Morrisville Hydroelectric Proj Water Quality - Decision on the Merits ( 2018 )


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  •                                            STATE OF VERMONT
    SUPERIOR COURT                                                              ENVIRONMENTAL DIVISION
    Environmental Division Unit                                                   Docket No. 103-9-16 Vtec
    Morrisville Hydroelectric Project Water
    Quality                                                             DECISION ON THE MERITS
    This is an appeal of a water quality certification issued by the Agency of Natural Resources
    to Morrisville Water and Light for the Morrisville Hydroelectric Project located on the Lamoille
    River and its tributaries in north-central Vermont. Morrisville Water and Light (MWL) applied for
    the certification in connection with a Federal Energy Regulatory Commission (FERC) relicensing
    application. The Agency of Natural Resources (ANR) issued a certification on August 9, 2016,
    which MWL subsequently appealed to this Court on September 7, 2016. American Whitewater
    and the Vermont Paddlers’ Club (AW/VPC), the Vermont Natural Resources Council (VNRC), and
    the Vermont Council of Trout Unlimited (TU) all filed cross-appeals.
    Procedural History
    MWL and AW/VPC each moved to file Amended Statements of Questions on December
    22, 2016. In a February 7, 2017 decision, the Court granted both motions. VNRC and TU filed a
    joint Statement of Questions on October 17, 2016.
    On June 13, 2017, we issued a decision on multiple motions to dismiss and motions for
    summary judgment. We dismissed MWL Questions 1, 2, 6, 8, and part of Question 3 addressing
    whether ANR was required by the Streamflow Procedure to consider economic and social issues
    when issuing certification on appeal.1 We granted ANR’s motion for summary judgment on the
    1
    MWL Question 1 asks: “For all facilities whether [ANR] failed to strike a balance between competing water
    uses in the public interest as required by ANR Streamflow Procedure in issuing the Water Quality Certification,
    including, but not limited to the policy of the State of Vermont to decrease Vermont’s dependence on non-
    renewable energy sources.”
    MWL Question 2 asks: “Regarding bypass flows at the Morrisville and Cady’s Falls facilities on the Lamoille
    River, whether ANR failed to adequately consider any public benefits or detriments associated with increasing
    conservation flows for previously approved facilities as required by ANR Streamflow Procedure.”
    MWL Question 6 asks: “Whether the downstream flow and drawdown conditions for the Green River facility
    are in excess of what is necessary to provide a ‘high quality aquatic habitat,’ pursuant to the Vermont Water Quality
    1
    remaining part of MWL Question 3 addressing whether ANR was required to consider social and
    economic issues when issuing the certification on appeal pursuant to the Vermont Water Quality
    Standards (VWQS) or various Vermont statutes. Further, we granted VNRC and TU’s motion for
    summary judgment on AW/VPC’s amended Question 3 and dismissed AW/VPC’s Question 14. 2
    On July 20, 2017, we granted ANR’s motion for summary judgment on AW/VPC Question 1. 3
    This matter was further narrowed by our March 14, 2018 decision granting ANR’s motion
    for summary judgment on MWL Questions 10 and 11.4 On March 23, 2018, we granted ANR’s
    motion for summary judgement on AW/VPC’s on Question 6 and partially on Question 2 (on the
    issue of whether ANR followed an adopted application process for the water quality certification
    presently on appeal).5 At trial, however, AW/VPC moved on the record to dismiss the remaining
    aspect of Question 2 (“Whether ANR has adopted by procedure an application process for the
    certification of hydroelectric projects in Vermont under Section 401 of the federal Clean Water
    Act as contemplated by 10 V.S.A. §§ 1004, 1006.”) which the Court granted.
    Standards, and whether higher allowed downstream flows during generation, and greater winter drawdown, would
    provide such habitat and meet all applicable requirements of the Vermont Water Quality Standards.”
    MWL Question 8 asks: “Regarding the Green River facility, whether ANR failed to give due consideration to
    the dam safety concerns posed by spillage that would result from the restrictions on reservoir drawdown and
    downstream flows.”
    2
    AW/VPC Amended Question 3 asks: “Whether whitewater boating on the Green River during natural high
    flow events and during scheduled releases is a designated use protected under Section 3-04(A)(6) of the [VWQS] for
    Class B waters, and if so, whether the Water Quality Certification should ensure the continued opportunity for
    whitewater boating on the Green River during natural high flow events and during scheduled recreational releases.”
    AW/VPC Amended Question 14 asks: “To the extent that the Water Quality Certification renders the project
    uneconomical and results in decommissioning, whether the Green River Dam should be removed due to its adverse
    impacts.”
    3
    AW/VPC Question 1 asks: (“Whether [ANR] waived issuance of a Water Quality Certification for the
    [Project] by failing to act on the application for Water Quality Certification . . .within one (1) year of receiving an
    application, in accordance with Section 401(a)(1) of the Clean Water Act, 
    33 U.S.C. § 1341
    (a)(1).”
    4
    MWL Question 10 asks: “Regarding the Green River facility, whether ANR failed to give due consideration
    to the dam safety concerns posed by spillage that would result from the restrictions on reservoir drawdown and
    downstream flows.”
    MWL Question 11 asks: “Whether the Water Quality Certification should be revised to specifically allow
    new flow and water level management conditions to be phased in over an extended period of time (10 years) to
    accommodate engineering design, permitting and construction of improvements need to implement new
    conditions.”
    5
    AW/VPC Question 6 asks: “Whether ANR has conducted any site specific flow studies documenting the
    impact of whitewater boating in compliance Section 3-01(C) and Section 1-02(E) of the [VWQS} and if not whether
    any determination by ANR regarding the impacts of whitewater boating is entitled to deference by the Court.”
    2
    The Court held a trial from April 2, 2018 to April 11, 2018 at the Vermont Superior Court,
    Costello Courthouse in Burlington, Vermont. We conducted a half-day site visit on April 13, 2018.
    Thereafter, the parties jointly requested an extended post-trial briefing schedule which the Court
    granted.
    MWL is represented by Gregory M. Eaton, Esq. and Clara E. Conklin, Esq. ANR is
    represented by Leslie A. Welts, Esq. and Kane H. Smart, Esq. AW/VPC is represented by Daniel P.
    Richardson, Esq. and Ryan P. Kane, Esq. VNRC is represented by Jon Groveman, Esq. TU is
    represented by Robert J. Carpenter, Esq.6
    Findings of Fact
    1.       On September 9, 2015, MWL submitted an application for a water quality certification to
    ANR for hydroelectric facilities located on the Lamoille River and its tributaries in north-central
    Vermont (the Project).
    2.       The Project consists of four facilities: the Morrisville Facility, the Cadys Falls Facility, the
    Green River Facility, and the Lake Elmore Facility. These facilities were constructed between the
    1890s and the 1940s.
    3.       Pursuant to its FERC application, MWL has sought to remove the Lake Elmore
    development from its FERC license.
    4.       The 2014 Vermont Water Quality Standards (VWQS) are applicable to the water quality
    certification on appeal.
    5.       The Project does not affect any high-quality waters. All relevant project waters are
    defined as Class B waters under the VWQS.
    6.       The Project was granted an original FERC license on August 21, 1981, which ran until April
    30, 2015.
    7.       The Project as currently operated does not meet the VWQS.
    8.       On August 9, 2016, ANR issued a water quality certification to MWL with conditions
    pursuant to the Clean Water Act (CWA) and the VWQS.
    6
    Friends of Green River Reservoir, represented by Anthony Iarrapino, Esq., the Towns of Morristown,
    Elmore, Eden, and Hyde Park, and self-represented litigants Christine Hallquist and Barrett M. Singer entered this
    matter as Interested Persons. None of these parties, however, participated in any aspect of the 8-day merits hearing.
    Therefore, at the close of evidence, the Court dismissed these parties as Interested Persons and converted their
    status to FYI only.
    3
    9.     On September 7, 2016, MWL appealed the water quality certification to this Court.
    Morrisville Facility
    10.    The Morrisville Facility is in Morristown, Vermont. The facility was originally constructed
    in 1924.
    11.    The Morrisville Facility has a small impoundment and has a dam that is approximately 216
    feet long at the main spillway.
    12.    The facility is licensed to operate in modified run-of-river mode and both the water quality
    certification and MWL’s proposed conditions seek to transition the facility into true run-of-river
    operation.
    13.    The Morrisville Facility currently has an inflatable crestgate installed on the dam.
    14.    There are two bypass reaches at the facility, a primary reach approximately 400 feet long
    and a secondary reach approximately 800 feet long.
    15.    MWL is currently required to maintain a bypass flow of 12 cubic feet per second (cfs) in
    the primary bypass reach. There is no required flow in the secondary bypass reach.
    16.    The substrate in the primary bypass reach is primarily bedrock. The reach lacks gravel
    and cobble substrate that would support macroinvertebrate habitat that would provide a food
    source to fish or other aquatic biota. Because of this, the reach is unlikely to support trout
    spawning or incubation.
    17.    At the end of the reach there is a large drop off approximately 15 feet tall.
    18.    Brook trout, brown trout, and rainbow trout have been found at the primary bypass reach
    and were used as target species.
    19.    Fish move through the bypass reach over the dam down the bypass reach and over the
    drop off to the Lamoille River. It is highly unlikely that fish move up-stream from the Lamoille
    River towards the dam because of the drop off.
    20.    The Morrisville Facility and the primary bypass reach are visible from a bridge off B Street
    in Morristown.
    21.    The Morrisville Facility is currently manually operated and does not have the necessary
    equipment to operate remotely.
    4
    22.    MWL retained the consulting firm Gomez & Sullivan, and with participation from ANR,
    Gomez & Sullivan conducted a habitat-flow study within the primary bypass reach to determine
    the flow necessary to meet VWQS.
    23.    ANR, MWL, and other participating parties agreed upon the study’s scope and goals.
    24.    Gomez & Sullivan conducted a habitat suitability analysis for adult and juvenile rainbow
    trout, brook trout, and brown trout (the target species).
    25.    Flows of 4.5, 21, 59, and 91 cfs were evaluated in the bypass reach to assess downstream
    passage and habitat connectivity for fish, as well as water movement and the availability for
    cover. These flows represented leakage flow, one-inch spill, 0.2 cubic feet per second per square
    mile (cfsm), and 0.4 cfsm flow scenarios.
    26.    From this evaluation, the analysis produced habitat-flow curves representing the amount
    of habitat observed at the different flows for each target species at relevant life stages.
    27.    Both ANR and MWL relied upon the habitat-flow curves in reaching the respective flow
    regime at the Morrisville Facility.
    28.    The Gomez & Sullivan analysis concluded that a flow of 59 cfs would provide 73% of
    available habitat relative to the maximum observed available habitat for adult rainbow trout,
    which is the most limiting habitat species, of that provided at a flow of 91 cfs.
    29.    In 2017, MWL consultant Meddie Perry conducted an assessment of the Project and its
    compliance with the relevant sections of the VWQS. Additionally, Mr. Perry created a flow-
    energy model to evaluate how changes in flow over time relate to hydroelectric generation. Mr.
    Perry also conducted an aesthetic evaluation.
    30.    Mr. Perry is a senior hydrogeologist with the consulting firm VHB. Mr. Perry has a
    Bachelor’s degree in environmental science and biology and many years of relevant work
    experience in the area of hydrology.
    31.    Mr. Perry combined the results of the flow-energy model and the habitat-flow analysis to
    develop a flow and habitat duration analysis to evaluate the availability of habitat over time
    under different scenarios.
    32.    Mary Nealon aided Mr. Perry in his analysis of the Morrisville Facility. Ms. Nealon is a
    fisheries biologist with Bear Creek Environmental, LLC. Ms. Nealon and Mr. Perry used habitat
    5
    supply information from the Gomez & Sullivan study, United States Geological Survey (USGS)
    streamflow data from the USGS streamflow gauging station in Johnson, Vermont, and project
    operation information to perform a habitat time series analysis. In addition, Ms. Nealon made
    general habitat observations.
    33.       The original analysis did not include rainbow trout. An updated time series analysis was
    provided which analyzed that species. Both Mr. Perry and Ms. Nealon testified that their overall
    conclusions regarding the facility were not changed by the updated time series analysis.
    34.       From this, Mr. Perry concluded that a flow of 43 cfs in the primary bypass reach would
    provide the target species and their life stages, on annual average, 80% of the amount of suitable
    habitat that would be available under natural flow conditions.
    35.       The results also concluded that a flow of 43 cfs would provide on average annually,
    relative to natural flow conditions, 70% of available habitat for adult rainbow trout, 76% of
    habitat for juvenile rainbow trout, 79% of habitat for adult brown and brook trout, and 94% of
    habitat for juvenile brown and brook trout.
    36.       Ms. Nealon concluded that a flow of 43 cfs in the bypass reach provided adequate habitat
    connectivity. This allows fish that wash over the dam to move through and exit the bypass reach
    safely.
    37.       Ms. Nealon concluded that a flow of 43 cfs provided adequate cover in the forms of
    turbulence and depth. Ms. Nealon observed that the pool in the bypass reach and holes in the
    bedrock provide high quality cover for juvenile and adult trout at this flow. A flow of 43 cfs
    provides turbulence in the reach that would provide additional cover.
    38.       In 2012, Gomez & Sullivan also conducted a water quality study at the Morrisville Facility.
    The study monitored dissolved oxygen (DO) and temperature at the facility’s then-current flow
    regime of 12 cfs.
    39.       The water quality study consisted of bi-monthly DO and temperature readings in the
    development’s reservoir, penstock tap, and tail race; as well as observations of river flows,
    weather, spillage, and turbine operations during sampling. Periodic data was collected at these
    locations from May 2012 to October 2012. Continuous data was collected from September 6 to
    October 23.
    6
    40.       A draft sampling plan was submitted to ANR for comments prior to beginning the study.
    Comments submitted by ANR were then incorporated into the final study plan, which was also
    submitted to ANR.
    41.       The water quality study concluded that the Morrisville Facility was complying with the DO
    and temperature requirements of the VWQS.
    42.       Mr. Perry concluded in his analysis of the bypass reach that a flow of 43 cfs complies with
    the DO and temperature requirements of the VWQS because the Gomez & Sullivan water quality
    study concluded that a flow of 12 cfs was in compliance with these standards.
    43.       Ms. Nealon concluded that a flow of 43 cfs in the primary bypass reach would meet the
    criteria for DO and temperature, based on the existing Gomez & Sullivan data.
    44.       In 2012, Gomez & Sullivan also conducted an aesthetics flow study in connection with
    ANR and MWL. The study was conducted pursuant to a mutually agreed upon study plan and
    involved a team of Gomez & Sullivan representatives, ANR representatives, and MWL
    representatives observing predetermined demonstration flows from predetermined vantage
    points.
    45.       Flows of 4.5, 21, 59, and 91 cfs were observed in the primary bypass reach. While there
    were 3 total predetermined vantage points, only one was used for the primary bypass reach. This
    point was located on the bridge in front of the dam, over the reach. These flows represented
    leakage flow, one-inch spill over the dam, 0.2 cfsm, and 0.4 cfsm flow scenarios.
    46.       A flow of 21 cfs in the primary bypass reach provided good aesthetic value at the primary
    bypass reach vantage point. This flow only provided fair aesthetic value in the secondary bypass
    reach. Good aesthetic value was observed in the secondary bypass reach at 59 cfs, which
    provided good to excellent aesthetic value in the primary bypass reach.
    47.       In 2017, Mr. Perry conducted an independent aesthetic evaluation of additional
    demonstration flows of 12, 28, 43, and 70 cfs at the Morrisville Facility.
    48.       Mr. Perry’s concluded that a flow of 43 cfs provided a full veil of whitewater over the crest
    of the dam, full water levels in the reach, scenic views of the ledge within the reach, a mixture of
    deep pools and whitewater, and pleasant auditory aesthetics. This flow would provide for
    7
    approximately two inches of spillage over the dam. Mr. Perry concluded that a 43 cfs flow would
    provide good aesthetic value at the primary bypass reach.
    49.    At 70 cfs, Mr. Perry concluded that other than an increase in the sound of falling water,
    the aesthetic value of the dam itself or in the reach were not improved.
    50.    Changes to the equipment at the Morrisville Facility will be needed to comply with either
    the water quality certification’s flow regime or MWL’s proposal.
    51.    Mr. Perry testified that the proposed 43 cfs condition does not balance social and
    economic factors, in accord with our prior order.
    52.    The Morrisville Facility is currently manually operated and lacks the equipment to be
    operated or monitored remotely so the facility would require automated and remote controls.
    Additionally, the facility would require the installation of automated communications equipment
    and other flow-measurement devices. MWL would need to make programming changes to the
    existing crestgate equipment.
    Cadys Falls Facility
    53.    The Cadys Falls Facility is in Morristown, Vermont. It was constructed in 1894 and
    reconstructed in 1906, 1914, and 1947.
    54.    The facility includes a 364-foot-long concrete dam and 186-foot spillway. Wooden panels
    are used as crestgates. These wooden panels are 3.5 feet high and are operated manually to
    adjust levels and flows.
    55.    The Cadys Falls Facility is manually operated and does not have the equipment necessary
    to operate or monitor the facility remotely.
    56.    The facility currently is licensed to operate in modified run-of-river mode.
    57.    The facility creates an approximately 150-acre impoundment, called Lake Lamoille.
    58.    There is a single bypass reach that is 1690 feet long. Currently, no minimum flow is
    required to be released into the bypass reach and the only flow in the reach is leakage from the
    dam. The leakage is roughly 5.5 cfs.
    59.    Existing flows in the bypass reach do not comply with the VWQS.
    60.    The bypass reach’s substrate is boulder and a mixture of cobble and gravel.
    8
    61.     Brook trout, brown trout, and rainbow trout are found in the bypass reach. The substrate
    can also support macroinvertebrates.
    62.     In 2012, Gomez & Sullivan, conducted a habitat-flow study in the bypass reach to
    determine the flow regime necessary to comply with the VWQS. The study’s scope and goals
    were agreed upon by ANR, MWL, and other interested participating parties.
    63.     Flows of 48, 67, 98, 139, and 163 cfs were observed in the bypass. Three representative
    transects were selected. Each transect fell into the “riffles” category, selected because of their
    flow sensitivity.
    64.     The Gomez & Sullivan study determined habitat suitabilities for macroinvertebrates and
    adult and juvenile rainbow trout, brook trout, and brown trout. This was done through
    measurements of depth, velocity, and substrate collected at the three representative transects
    for each of the five study flows.
    65.     These instream flows were evaluated using a transect-based modification to the Physical
    Habitat Simulation Model (PHABSIM) methodology. PHABSIM is part of the U.S. Fish and Wildlife
    Service’s Instream Flow Incremental Methodology (IFIM). IFIM is typically used to determine
    appropriate flow regimes in waters in which the natural flows are altered. PHABSIM modeling
    simulates river hydrology and habitat based on known species preferences for the specific
    physical habitat components of depth, velocity, and substrate. The end products are weighted
    usable areas, or habitat coverage, which serve as a function of streamflow at each life stage for
    a given species.
    66.     The modified PHABSIM methodology, which was employed by Gomez & Sullivan, similarly
    uses hydraulic information and aquatic habitat suitability index curves to understand the
    relationship between habitat and flow at each representative transect. Unlike the traditional
    PHABSIM, the modified method utilizes direct field-based measurements rather than modeling.
    67.     A modified PHABSIM approach is preferred over the traditional approach in steep or
    difficult to model reaches, like the Cadys Falls reach.
    68.     From this evaluation, the analysis produced habitat-flow curves representing the amount
    of habitat observed at the different study flows for each target species at relevant life stages.
    9
    69.    The analysis concluded that a flow of 100 cfs would provide 80% of that habitat that was
    available for the most limiting species, adult rainbow trout, that was available at the highest
    observed flow, 163 cfs. A flow of 98 cfs would provide 78% of available suitable habitat for this
    species and a flow of 65.5 cfs would provide for approximately 60% of available suitable habitat
    relative to the highest observed flow.
    70.    Both ANR and MWL relied upon the habitat-flow curves in reaching the respective flow
    regime at the Cadys Falls Facility.
    71.    In 2017, Mr. Perry created a flow-energy model to evaluate how flow changes over time
    relate to hydroelectric generation using the same methodology as with the Morrisville Facility.
    The results of this model were combined with the results of the habitat-flow study to create a
    flow and habitat duration analysis evaluating the overall habitat availability under different flow
    regimes.
    72.     Ms. Nealon and Mr. Perry used habitat supply information from the Gomez & Sullivan
    study, USGS streamflow data from the USGS streamflow gauging station in Johnson, Vermont,
    and project operation information to perform a habitat time series analysis. In addition, Ms.
    Nealon made general habitat observations.
    73.    The original analysis did not include rainbow trout. An updated time series analysis was
    provided which analyzed that species. Both Mr. Perry and Ms. Nealon testified that their overall
    conclusions regarding the facility were not changed by the updated time series analysis.
    74.    The flow and habitat duration analysis shows that a flow of 65.5 cfs would provide an
    annual average of 63% of the suitable habitat that is available under a natural flow regime.
    75.    The results also concluded that a flow of 65.5 cfs would provide on average annually,
    relative to natural flow conditions, 60% of habitat for adult rainbow trout, 64% of habitat for
    juvenile rainbow trout, 66% of habitat of adult brown and brook trout, 72% of habitat for juvenile
    brown and brook trout, and 58% of habitat for macroinvertebrates.
    76.    A flow of 65.5 cfs, as proposed by MWL, does not provide high quality aquatic habitat in
    the Cadys Falls bypass reach.
    77.    Ms. Nealon concluded that that a flow of 90 to 100 cfs would provide high quality aquatic
    habitat in the reach. At trial, Ms. Nealon recommended a flow of 90 cfs to meet this standard.
    10
    78.    MWL concedes that a flow of at least 90 cfs would provide high quality aquatic habitat in
    the reach.
    79.    MWL maintains that a flow of 100 cfs would result in a 21% decrease in renewable energy
    generation at the facility. A flow of 65.5 cfs would result in a 13% decrease in generation.
    80.    MWL asserts that a flow of 65.5 cfs would result in a reasonable balance between
    protecting and maintaining aquatic habitat in the reach and renewable energy generation.
    81.    In 2012, Gomez & Sullivan also performed a water quality study at the Cadys Falls Facility.
    The study monitored DO and temperature measurements.
    82.    The water quality study consisted of bi-monthly DO and temperature readings in the
    development’s reservoir, penstock tap, and downstream in the tail race; as well as observations
    of river flows, weather, spillage, and turbine operations during sampling. Periodic samples were
    taken at these locations from May 2012 to October 2012.
    83.    The water quality study concluded that these locations complied with the DO and
    temperature requirements of the VWQS.
    84.    In 2012, Gomez & Sullivan also performed an aesthetic flow study of the Cadys Falls
    Facility with the same participants, methods, and process as at the Morrisville Facility.
    85.    Five individuals observed three different flows of 27.7, 77.6, and 133.3 cfs in the bypass
    reach. Three vantage points were assessed; one located on the bridge downstream from the
    dam, one within the reach, and one at the dam itself.
    86.    The study concluded that a flow of 133.3 cfs provided good to good/excellent aesthetic
    value in the reach, whereas a flow of 77.6 cfs provided fair/good to good aesthetic value,
    depending on the vantage point. A flow of 27.7 cfs, however, did not provide good aesthetic
    value in the reach.
    87.    In 2017, Mr. Perry conducted an independent aesthetic evaluation of additional flows
    within the bypass reach. Mr. Perry observed flows of 53 and 100 cfs at three vantage points
    within the bypass reach; one viewing the dam, one viewing the bridge, and one in the middle of
    the reach.
    88.    Mr. Perry concluded that a flow rate of 53 cfs provided good aesthetic value throughout
    the reach. In reaching this conclusion, Mr. Perry asserted that this flow provided a full veil of
    11
    water over the crest of the dam, the bypass reach contained full water levels, and, within the
    reach, there was a variety of features such as pools, visible outcrops, riffles, and whitewater.
    Further, the flow produced pleasant auditory effects such as rushing and babbling water. Mr.
    Perry concluded that increasing the flow to 100 cfs did not improve these qualities.
    89.    MWL’s proposal of 65.5 cfs would result in some spillage over the crest of the dam.
    90.    The equipment currently at the Cadys Falls Facility is outdated. Equipment upgrades
    would be required regardless of what flow regime is mandated within the bypass reach.
    Green River Facility
    91.    The Green River Facility is in Hyde Park, Vermont. It was originally constructed in 1947
    and generation capacity was installed in 1984.
    92.    The facility has a 360-foot long, 105-foot high concrete arch damn. The facility is operated
    in a store and release mode. The facility was not designed to operate in run-of-river mode or to
    spill water over the dam crest.
    93.    The dam maintains, and uses stored water from, the Green River Reservoir. The reservoir
    is approximately 653 acres, has a normal maximum water elevation of 1220 feet, a maximum
    depth of 93 feet, and an average depth of 35 feet. The reservoir is characterized as large, and it
    is located in a small watershed.
    94.    The Green River is approximately 4.3 miles long with a culvert located on Garfield Road
    (Garfield Road culvert). The Garfield Road culvert likely impedes fish from traveling upstream.
    95.    The current operating license places conditions on the facility’s conservation flows,
    maximum generation flows, and maximum reservoir drawdown levels.
    96.    Current license conditions require a continuous 5.5 cfs conservation flow into the Green
    River. From November to April, there is a maximum generation flow of 283 cfs. From May to
    October, the maximum generation flow is set at 160 cfs, except when necessary to prevent
    spillage over the dam.
    97.    Generation cycles last a minimum of six hours.
    98.    From May to October, a one-foot maximum fluctuation in the reservoir level is permitted
    from the full reservoir elevation of 1220 feet. Additionally, the reservoir is managed to protect
    loon nesting habitat during this time. From December 1 to April 30, a 10-foot maximum total
    12
    drawdown is allowed from this elevation (the winter drawdown). The reservoir level must be
    refilled no later than May 1.
    99.     MWL determines the actual amount of winter drawdown based on annual snowpack. The
    average drawdown is 3.7 feet, the maximum on record was 5.9 feet, and the minimum was 0
    feet.
    100.    Fisheries management goals for the Green River Reservoir include protecting spawning
    fish, eggs, and fry from harmful water level fluctuation in the spring and early summer and
    maintaining the ecological integrity of the littoral zones and their habitat value for fish
    populations.
    101.    Littoral zones serve a vital role in lake and reservoir ecosystems and influence the overall
    productivity of the lentic system.
    102.    Light penetrates the littoral zones. This light produces macrophyte (plant) growth, which
    enables diverse species composition and habitat complexity, supporting life cycle functions at
    each level of the food chain.
    103.    Drawdowns cause dewatering of littoral zones. In the winter, these drawdowns can
    prevent the establishment of healthy near-shore communities which provide habitat and life
    cycle functions, such as forage and reproduction, for organisms serving as food sources for larger
    fish and wildlife.
    104.    Dewatering also exposes aquatic plants to drying and freezing conditions and can remove
    fine sediments from the near-shore area which support macrophyte growth.
    105.    Drawdowns are associated with reduced abundance and richness of larger, longer-lived
    macroinvertebrates.
    106.    Natural water fluctuations can promote structural and biotic diversity by providing a
    wider variety of habitats and conditions for different species through the disturbance.
    107.    The Green River Reservoir’s natural fluctuation is 1.7 feet.
    108.    A six-foot winter drawdown, as proposed by MWL, would result in the dewatering of
    approximately 80 acres of near-shore habitat at the reservoir.
    109.    A 1.5-foot drawdown, as imposed by the 2016 water quality certification, would resulting
    in dewatering consistent with the limits of the reservoir’s natural fluctuation.
    13
    110.   In the Green River Reservoir, there are populations of smallmouth bass, chain pickerel,
    northern pike, yellow perch, brown bullhead, and pumpkinseed sunfish.
    111.   Bass species begin spawning in late-May. Spawning requires the maintenance of a stable
    reservoir elevation from May into July to protect the spawning, incubation, and black fry stages.
    112.   Two or three territorial loon pairs are typically supported from May to August during
    nesting season.
    113.   Loons are a species of great conservation need in Vermont. They nest near the edges of
    the water and their reproductive success can be negatively affected by water fluctuations.
    114.   In 2012, the consulting firm TRC conducted an aquatic resource assessment of the near-
    shore aquatic habitat. The assessment sought to inventory the existing habitat within the
    drawdown zone and assess the effect project operations have on the availability of aquatic
    habitat by comparison to other sites. The assessment was a cursory evaluation that failed to
    achieve study objectives.
    115.   ANR performed a littoral habitat assessment of the Green River Reservoir in 2014. The
    assessment sampled 17 sites at the reservoir and compared the Green River Reservoir’s littoral
    habitat to those of reference waterbodies in Vermont.
    116.   The reference waterbodies were eight large naturally occurring mesotrophic lakes that
    were sampled by ANR in 2007 and 2008, at which 54 sites were sampled. The assessment states
    that these samples provided conditions of waterbody types like that of the Green River Reservoir
    and were of similar size and trophic status. These reference sites represented minimally
    impacted conditions, and a range of biological, physical, and chemical attributes that were
    potentially attainable in the Green River Reservoir.
    117.   Sites were assessed for substrate composition, aquatic plant cover, woody debris,
    embeddedness, odonate exuviae (dragonfly exoskeletons), and riparian habitat characteristics.
    118.   The assessment concluded that the reservoir’s littoral zone had many areas that were
    highly suitable for aquatic macrophyte growth that currently lacked macrophytes and, as
    compared to these other lakes, the reservoir had less aquatic plant cover and odonate exuviae.
    The assessment concluded that this impact is consistent with water level fluctuations.
    14
    119.      The 2014 littoral habitat assessment was implemented to study the effects of shoreline
    development and was not conducted in direct relationship with the Project.
    120.      In 2017, MWL consultants EcoLogic conducted a study to assess the appropriateness of a
    1.5-foot winter drawdown (the EcoLogic study).
    121.      The study was conducted by Kurt Jirka, an associate scientist with EcoLogic. Mr. Jirka has
    a Bachelor’s degree in wildlife ecology and a Master’s in fisheries science. He has over thirty
    years of biological consulting experience.
    122.      The EcoLogic study only involved a qualitative review and contained no quantitative or
    comparative analysis. The participants observed the habitat and species composition along the
    perimeter of the reservoir and compiled a list of the macrophyte species observed. No data was
    collected regarding macroinvertebrates.
    123.      There is a self-sustaining population of brook trout located above the Garfield Road
    culvert. Below the culvert there are brook trout, brown trout, and rainbow trout populations.
    Adult brown and rainbow trout successfully spawn in the lower portion of the river.
    124.      Other species found in the Green River include: blacknose dace, creek cub, lake chub,
    longnose dace, Northern redbelly dace, pumpkinseed, slimy sculpin, longnose sucker, and white
    sucker.
    125.      Fisheries management goals for the Green River include management for wild brook,
    brown, and rainbow trout and improvement of the flow regime to provide high quality aquatic
    habitat for all life stages of trout.
    126.      Current conditions at the Green River do not meet the VWQS.
    127.      Historical data collected prior to the construction of the dam indicates the following
    monthly median flows: January 13.0 cfs, February 9.8 cfs, March 14.0 cfs, April 88.0 cfs, May 36.0
    cfs, June 17.0 cfs, July 11.0 cfs, August 8.6 cfs, September 9.8 cfs, October 17.0 cfs, November
    25.0 cfs, December 17.0 cfs.
    128.      The Green River provides relatively abundant spawning and incubation habitat for many
    fish species, but particularly trout species.
    129.      Overwintering and reproductive requirements are presently being supported by the
    Green River.
    15
    130.   Habitat found along the Green River includes bedrock gorges, confined riffle-pools,
    confined step-pools, unconfined riffle-pools, and wetland channels.
    131.   Whitewater boating generally and boating on scheduled releases (together, whitewater
    boating) are existing uses of the Green River. Whitewater boating occurs year-round on both
    naturally occurring high flow events and scheduled releases.
    132.   MWL has provided two or three scheduled releases annually to support whitewater
    boating on the Green River. The releases last at least five hours.
    133.   MWL conducted a whitewater boating study to address the whitewater boating activities
    on the Green River. The study concluded that the minimum flow required to safely support
    whitewater boating is between 128 cfs and 140 cfs. A flow of 222 cfs provides the best flow level
    for a standard run and a flow of 280 cfs provides the best level for a highly challenging run.
    134.   Natural flows of 128 cfs or above have historically occurred within the Green River.
    135.   MWL asserts that natural high flows over 70 cfs will be passed downstream, outside of
    the winter drawdown and spring refill period. The water quality certification requires the
    passage of natural high flows over 128 cfs From June 1 to December 14. Additionally, natural
    high flows would be required to be passed after April 1 after the reservoir has been refilled.
    136.   Time shifting is when a naturally occurring high flow is stored for a period and then
    released. In the context of whitewater boating, this would result in the storage of natural high
    flows that occur when whitewater boating is unlikely to occur, such as overnight or during the
    weekdays, until whitewater boaters are likely to boat, such as daylight hours on the weekend.
    137.   In order for a time shifted release to be proper, it must account for timing, frequency,
    rate of change (ramping), magnitude and amplitude, and duration.
    138.   In 2012, Gomez & Sullivan, with ANR participation, conducted a habitat-flow study to
    quantitatively assess the relationship between flow and aquatic habitat for selected target
    organisms in the Green River. The study’s scope and goals were agreed upon by MWL, ANR, and
    other participating and interested parties.
    139.   This study mapped the habitat along the river and collected data at nine transects. The
    transects were selected to be representative of various habitat conditions. Five of the transects
    were “spawning transects,” which were transects identified as likely spawning areas.
    16
    140.     Flows of 10, 75, and 160 cfs were observed. Depth, velocity, substrate, and cover
    measurements were collected at each flow.
    141.     Target species and life stages included: spawning, incubation, early fry, late fry, juvenile,
    and adult stages for brook, brown, and rainbow trout, spawning and incubation stages for
    longnose sucker, and macroinvertebrates.
    142.     The habitat-flow study produced habitat-flow curves used to determine the flows at
    which the maximum amount of suitable habitat was available for each life stage of the target
    species, together with a range of flows providing at least 80% of the maximum amount of suitable
    habitat potentially provided. The curves can be summarized as follows:
    Exhibit I at 8-11.
    143.     Rapid flow fluctuations caused by hydropeaking (the shifting from low conservation flows
    to high generation flows) can impact fish populations through dewatering, stranding, disruption
    of spawning or migration, and habitat loss. These occurrences can have the largest effect on
    immobile species or life stages, because they cannot relocate to suitable habitat when the shifts
    occur.
    17
    144.      ANR conducted dual flow analysis using the results of the habitat-flow study. This analysis
    accounts for species immobility and quantifies the remaining habitat available to a species and
    life stage under a peaking regime.
    145.      The dual flow analysis reached the following results:
    146.      In 2017, Mr. Perry created a flow-energy model to assess how flows compare to a natural
    flow regime, evaluate how inputs to and from storage in the reservoir relate to hydroelectric
    generation, quantify changes in energy production resulting from different flow regimes, and
    analyze the aquatic habitat in the river. Mr. Perry employed the same methodology at the Green
    River as used at the Morrisville and Cadys Falls Facilities. Similarly, the flow-energy model was
    combined with the habitat-flow study in the same manner described above to develop a flow
    and habitat duration analysis. The flow and habitat duration analysis evaluated the overall
    habitat availability under different flow scenarios. Ms. Nealon aided in this analysis.
    147.      The original analysis did not include rainbow trout. An updated time series analysis was
    provided which analyzed the species. Both Mr. Perry and Ms. Nealon testified that their overall
    conclusions regarding the facility were not changed by the updated time series analysis.
    148.      Mr. Perry also reviewed Ms. Nealon’s fish population study, USGS data, and Mr. Jirka’s
    report.
    149.      Mr. Perry and Ms. Nealon observed flows of 5.5, 60, and 100 cfs.
    150.      Ms. Nealon walked the entirety of the Green River from the dam to its confluence with
    the Lamoille River. She characterized fish habitat throughout the river. The three main types of
    18
    habitat in the Green River are bedrock gorge, confined valley with riffle pool habitat, and
    unconfined valley with wetlands adjacent to the channel.
    151.   Ms. Nealon observed that the Green River has good channel and bank integrity under
    existing conditions and observed little bank erosion and scour.
    152.   In 2017, Ms. Nealon conducted a fish population survey in the Green River. The fish
    population survey sought to gain site-specific data within the river to determine whether existing
    conditions met the aquatic biota and habitat requirements of the VWQS. The fish population
    study used the Index of Biotic Integrity (IBI) and the results of the study to evaluate the fish
    community.
    153.   The IBI looks at the structure, function, and abundance of a given fish community to
    determine if there are deviations between the sampled community and a reference community.
    The IBI does not directly address the impacts of flow.
    154.   Ms. Nealon used electrofishing during fish population monitoring. She selected four
    electrofishing stations at river mile (RM) 3.5, RM 3.2, RM 2.9, and RM 0.1. At each station, Ms.
    Nealon and her team conducted multiple electrofishing passes. Fish population estimates were
    calculated based on this. Then the Cold Water IBI (CWIBI) and Mixed Water IBI (MWIBI) were
    used to score each station and evaluate the health of the fish.
    155.   The fish population monitoring and analysis indicated that there is a self-sustaining
    population of native trout, there is excellent natural reproduction of fish, and there is full support
    of aquatic biota and habitat. All life cycle functions like overwintering and reproductive
    requirements are maintained and protected under existing conditions.
    156.   MWL concluded that current conditions in the Green River are in compliance with VWQS
    aquatic habitat and biota requirements.
    157.   The Green River Facility is currently manually operated and does not have the necessary
    equipment to be operated remotely. The reservoir level, however, can be adjusted remotely.
    158.   To comply with any new flow regime, MWL would need to install utility lines, sensors, and
    controls to regulate flow, including an aerator turbine.
    19
    Conclusions of Law
    CWA § 401(a)(1) requires that an “applicant for a federal license or permit for any activity
    . . . which may result in any discharge into . . . navigable waters” obtain a water quality
    certification (§ 401 certification) from the state to present to the federal licensing or permitting
    agency. 
    33 U.S.C. § 1341
    (a)(1). A § 401 certification is meant to ensure that the activity to be
    licensed or permitted will comply with “effluent limitations and other limitations” required by
    the CWA and “any other appropriate requirement of State law.” 
    33 U.S.C. § 1341
    (d).
    The state agency tasked with certifying the activity can impose reasonable conditions and
    limitations in a § 401 certification to ensure compliance with these laws. PUD No. 1 of Jefferson
    Cty. v. Washington Dep’t of Ecology, 
    511 U.S. 700
    , 712 (1994); 33 U.S.C § 1341(d). The Vermont
    legislature has delegated the responsibility of administering § 401 certifications to ANR. 10 V.S.A.
    § 1004.
    Pursuant to CWA § 303, states are required to adopt water quality standards, which are
    approved by the U.S. Environmental Protection Agency (EPA). 
    33 U.S.C. § 1313
     (calling for water
    quality standards); 
    40 C.F.R. § 131
     (EPA regulations regarding the procedures for establishing
    water quality standards). The state water quality standards adopted pursuant to CWA § 303 are
    among the “other limitations” that must be complied with for § 401 certification; “limitations to
    assure compliance with state water quality standards” also fall into the category of “other
    appropriate requirement[s] of state law” required by § 401 certification.7 PUD No. 1, 511 U.S. at
    713; 
    40 C.F.R. § 121.2
    (a)(3) (indicating that a § 401 certification must give “reasonable assurance”
    that the activity will not violate state water quality standards).
    Pursuant to § 303, Vermont has adopted the VWQS. In re Clyde River Hydroelectric
    Project, 
    2006 VT 11
    , ¶ 3, 
    170 Vt. 606
    . The VWQS state that they are intended to achieve the
    goals set out in both the CWA and the first section of the Vermont Water Pollution Control Act,
    10 V.S.A. § 1250. VWQS § 1-02. Any § 401 certification issued in Vermont must ensure that the
    activity certified will comply with the VWQS. See PUD No. 1, 
    511 U.S. 700
    ; 
    40 C.F.R. § 121
    .
    7
    The U.S. Supreme Court has declined to “speculate on what additional state laws, if any, might be
    incorporated by [the ‘other appropriate requirement of state law’] language” set out in CWA § 401. See PUD No. 1,
    511 U.S. at 713.
    20
    In the present matter, MWL is in the process of applying to the Federal Energy Regulatory
    Commission (FERC) for a license for the Project. As a part of this license application process, MWL
    has applied for a § 401 certification with ANR. ANR issued a § 401 certification to MWL for the
    Project and MWL, AW/VPC, VNRC, and TU appealed that certification to this Court. See 10 V.S.A.
    § 8504(a).
    In considering an appeal of a § 401 certification, the Court’s role is to determine whether
    the Project complies with the provisions of the CWA specified in § 401, the VWQS, and any other
    appropriate state law; and whether any conditions or limitations should be imposed within the
    § 401 certification to ensure compliance. See 10 V.S.A. § 8504(h) (calling for de novo review). 8
    We first examine what the VWQS require from the Project in terms of supporting and maintaining
    the “designated” and “existing” uses of the respective waterbodies. We then consider whether
    ANR has appropriately interpreted and applied the VWQS in establishing the conditions of the
    water quality certification. This includes an evaluation of whether ANR properly construed the
    term “high quality aquatic habitat” in determining whether it is supplied by the proposed
    conditions for the Project.
    We then turn our discussion to each of the three facilities individually to assess what
    specific limitations on their operations are necessary to satisfy the VWQS. Finally, we decide on
    the duration of a phase-in period, during which the Project will operate under current license
    conditions while MWL brings itself into compliance with the new conditions set forth in this
    decision.
    I.       Designated uses of the Project
    States take a variety of considerations into account when formulating their water quality
    standards. Some of these considerations are self-imposed by the state, while others are required
    by the CWA. “Designated uses” are of the latter type; states must consider a waterbody’s
    designated uses in setting their water quality standards, pursuant to the CWA and EPA
    regulations. 
    33 U.S.C. § 1313
    (c)(2)(A) (revised or new standards “shall consist of the designated
    uses of the navigable waters involved and the water quality criteria for such waters based upon
    8
    As stated in our June 13, 2017 decision, and pursuant to our vested rights doctrine, the VWQS that went
    into effect on October 30, 2014 are applicable to this case. See In re Morrisville Hydroelectric Project Water Quality,
    No. 103-9-16 Vtec, slip op. at n. 4 (Vt. Super. Ct. Envtl. Div. Jun. 13, 2017) (Walsh, J.) (citations omitted).
    21
    such uses”). These are some of the uses of the waterbody “to be achieved and protected” by
    state water quality standards. 
    40 C.F.R. § 131.10
     (setting out guidelines for “Designation of uses”
    and describing what “the State must take into consideration” in designating uses).
    Federal regulations define designated uses as “those uses specified in water quality
    standards for each waterbody or segment whether or not they are being attained.” 
    40 C.F.R. § 131.3
    (f). The VWQS define designated uses as “any value or use, whether presently occurring
    or not, that is specified in the management objectives for each class of water as set forth in §§ 3-
    02(A) [Class A(1) water], 3-03(A) [Class A(2) waters], and 3-04(A) [Class B waters] of these rules.”
    VWQS § 1-01(B)(14).
    States are required to define designated uses at least as specific as the uses identified in
    the CWA, those of drinking water supply, protection and propagation of fish, shellfish, and
    wildlife, recreation, agricultural, industrial, and navigation. But states do have discretion to define
    designated uses in more or less specific terms. 33 U.S.C §§ 1251(a) (setting out goals and policy
    of the CWA), 1313(c) (stating that water quality standards must take into consideration and
    protect the CWA purposes); 
    40 C.F.R. § 131.10
    (c) (allowing states to designate sub-categories of
    uses); U.S. Envt’l. Prot. Agency Water Quality Standards Handbook §§ 2.3, 4.4.1 (1994) available
    at    https://www.epa.gov/wqs-tech/water-quality-standards-handbook               [hereinafter    EPA
    Handbook].
    For each relevant waterbody, states are required to manage water “to achieve and
    maintain a level of quality that fully supports” the designated uses of that waterbody. VWQS § 3-
    04(A); see also 
    40 C.F.R. § 131.10
    (a) (designated uses are “to be achieved and protected”). Uses
    that the state defines more specifically than required by the CWA, and which are not designated,
    do not have to be supported under the requirements of the CWA. See, 40 C.F.R. 131.10(k)(2).
    In this case, ANR is the authorized agency and must identify designated uses for
    waterbodies, regardless of whether those uses are fully supported at present. See, e.g., In re
    Stormwater Npdes Petition, No. 14-1-07 Vtec, slip op. at 1-2 (Vt. Envtl. Ct. Aug. 28, 2008) (Durkin,
    J.) (ANR determination that five streams did not presently support the “aquatic life” use for which
    the streams were designated). Designated uses in Class B waters, as here, include: aquatic biota,
    wildlife, and aquatic habitat; aesthetics; public water supply; irrigation of crops and other
    22
    agricultural uses; swimming and other primary contact recreational uses; and boating, fishing
    and other recreational uses. VWQS § 3-04(A)(1)-(6).
    II.      Existing uses of the Project
    States must also account for “existing uses” when setting their water quality standards.
    Existing uses are defined by the EPA as “those uses actually attained in the waterbody on or after
    November 28, 1975, whether or not they are included in the water quality standards.” 
    40 C.F.R. § 131.3
    (e). The VWQS define an existing use as “a use which has actually occurred on or after
    November 28, 1975, in or on waters, whether or not the use is included in the standard for
    classification of the waters, and whether or not the use is presently occurring.” VWQS § 1-
    01(B)(18). A state’s water quality standards must include an antidegradation policy that is
    intended to protect “existing beneficial uses of navigable waters, preventing their further
    degradation.” PUD No. 1, 51 U.S. at 705; 
    40 C.F.R. § 131.12
    (a) (requiring states to adopt
    antidegradation polices to protect and maintain existing uses).
    Further, existing uses are relevant when determining whether a use was both a
    designated use and an existing use. If so, the use cannot be removed from the state water quality
    standards. 
    40 C.F.R. § 131.10
    (h)(1).
    In Vermont, existing uses may be identified either through the basin planning process 9,
    or on a case-by-case basis “during the consideration of an application.” VWQS §§ 1-03(B)(1), 1-
    02(D)(2) and (4). When identifying existing uses, ANR considers:
    a. Aquatic biota and wildlife that utilize or are present in the waters;
    b. Habitat that supports existing aquatic biota, wildlife, or plant life;
    c. The use of the waters for recreation or fishing;
    d. The use of water for water supply, or commercial activity that depends directly
    on the preservation of an existing high level of water quality; and
    e. . . . the factors considered . . . above, evidence of the use’s ecological
    significance in the functioning of the ecosystem or evidence of the use’s rarity.
    VWQS § 1-03(B)(1)(a)-(e).
    9
    In the basin planning process, ANR develops a management strategy for each of the fifteen major drainage basin
    units in Vermont. The process involves coordinating conservation, mitigation, and remediation efforts of the
    stakeholders in the basin. directed at water quality. http://dec.vermont.gov/watershed/map/basin-
    planning/process.
    23
    Central to this appeal is whether or not the hydroelectric generation of the Project’s facilities
    qualifies as a “commercial activity that depends directly on the preservation of an existing high
    level of water quality” under VWQS § 1-03(B)(1)(d). As discussed below, in Section IV.b, because
    we recognize that the Project’s hydroelectric activities are existing uses, they must be factored
    in when determining the requirements of the VWQS.
    ANR has identified some additional existing uses in the 2016 Tactical Basin Plan for the
    Lamoille Basin (the Basin Plan). The Basin Plan identifies swimming, recreational boating,
    recreational fishing, and use as a public water supply as existing uses in the basin. Additionally,
    for the reasons set out in our March 23, 2018 decision, which we incorporate here by reference,
    the Basin Plan identifies whitewater boating as an existing use on the Green River.
    III.      Whether ANR may impose conditions beyond what is necessary to meet the VWQS
    At the core of this appeal is MWL’s assertion that the conditions imposed by ANR through
    the 2016 water quality certification are in excess of what is necessary to ensure compliance with
    the CWA and the VWQS. MWL offers alternative conditions to satisfy the CWA. We must review
    the parties’ competing standards to determine which comply with the VWQS.
    The Court applies the principles of statutory construction when we interpret
    administrative regulations like the VWQS. In re Sheffield Wind Project, No. 252-10-08 Vtec, slip
    op. at 3 (Vt. Envtl. Ct. Sept. 29, 2009) (Wright, J.) (citing In re Williston Inn Grp., 
    2008 VT 47
    , ¶ 14,
    
    183 Vt. 621
    ; Conservation Law Found. v. Burke, 
    162 Vt. 115
    , 121 (1993)). The Court’s goal is to
    “discern the intent of the drafters . . . by reference to the plain meaning of the regulatory
    language.” Willison Inn Grp., 2008 VT at ¶ 14 (citing Slocum v. Dep’t of Soc. Welfare, 
    154 Vt. 474
    ,
    478 (1990)).
    The Court gives “substantial deference to an agency’s interpretation of its own
    regulations,” here, the VWQS. In re ANR Permits in Lowell Mountain Wind Project, 
    2014 VT 50
    ,
    ¶ 15, 
    196 Vt. 467
     (citing In re Peel Gallery of Fine Arts, 
    149 Vt. 348
    , 351 (1988)). “Absent a clear
    and convincing showing to the contrary, decisions made within the expertise of such agencies
    are presumed correct, valid and reasonable.” In re Johnston, 
    145 Vt. 318
    , 322 (1985). Parties
    challenging ANR’s interpretation “bear the burden of showing that ANR’s interpretation is wholly
    irrational and unreasonable in relation to its intended purpose.” ANR Permits, 
    2014 VT 50
    , ¶ 17
    24
    (citations omitted); see also Plum Creek Me. Timberlands, LLC v. VT. Dep’t of Forests, Parks &
    Recreation, 
    2016 VT 103
    , ¶ 28, 
    203 Vt. 197
    ; In re Costco Stormwater Discharge Permit, 
    2016 VT 86
    , ¶ 5, 
    202 Vt. 564
    .
    As there are no express standards to determine compliance with the VWQS, we must look
    to the document in its entirety. The VWQS are intended to meet the goals of the Vermont Water
    Quality Policy, and the objectives of the CWA “to restore and maintain the chemical, physical,
    and biological integrity of the Nation’s waters.” VWQS § 1-02; 
    33 U.S.C. § 1251
    (a).
    The VWQS Hydrology Policy provides some guidance regarding the management of water
    resources in the state. Pursuant to the Hydrology Policy, when determining conditions regarding
    water resource management, the conditions should provide a means to “preserve, to the extent
    practicable, the natural flow regime of waters.” VWQS § 1-02(E)(1). This management “requires
    careful consideration of the interruption of the natural flow regime” and impacts resulting from
    dams. Id.
    The natural flow regime is “a water’s characteristic variability in flow rates and water
    levels, annually, seasonally, and daily, without the influence of artificial flow regulation.” VWQS
    § 1-01(B)(30). Pursuant to the Hydrology Criteria, “[a]ny change from the natural flow regime
    shall provide for maintenance of flow characteristics that ensure the full support of uses and
    comply with the applicable water quality criteria.”10 VWQS § 3-01(C)(1)(c).
    In addition, water must be managed to achieve “the level of water quality necessary to
    protect” existing uses of waters. VWQS § 1-03(B)(1) (emphasis added); see also VWQS § 1-
    03(C)(1) (“In all cases, the level of water quality necessary to maintain and protect all existing
    uses as well as applicable water quality criteria shall be maintained”) (emphasis added). The
    existing uses of waters “shall be maintained and protected regardless of the water’s
    classification.” Id. Class B waters, as are at issue here, also “shall be managed to achieve and
    maintain a level of quality that fully supports . . . designated uses.” VWQS § 3-04(A).
    10
    To determine compliance with this subsection, the preferred method is site-specific flow studies. VWQS
    § 3-01(C)(1)(c). The studies must be “sufficiently based on scientific knowledge . . . [and] [i]n the case of aquatic
    habitat studies, those methodologies that are acceptable . . . include the Instream Flow Incremental Methodology
    (IFIM), as well as other comparable methods of evaluation deemed appropriate by the Secretary.” VWQS §3-
    01(D)(2)(a).
    25
    The determination of what is “necessary” to support the existing uses of the waterbodies
    at issue, to support their designated uses, and to meet all relevant aspects of the VWQS was
    heavily debated by the parties’ experts at trial.
    a. High quality aquatic habitat
    Also heavily debated were the water quality conditions necessary to support the
    designated use of aquatic biota, wildlife, and aquatic habitat. Pursuant VWQS § 3-04(A)(1), Class
    B waters, as at issue in this appeal, must support aquatic biota, wildlife, and aquatic habitat.
    VWQS § 3-04(A)(1). This designated use is supported by sustaining “high quality aquatic habitat”
    in the applicable waters. Id. The different operational regimes ANR and MWL would impose on
    the Project produce differing levels of habitat availability and quality. We must determine what
    water quality conditions contribute to high quality aquatic habitat, and which operational regime
    meets those conditions, to ensure compliance with the VWQS.
    High quality aquatic habitat is not defined by the VWQS. The VWQS provide some
    guidance, however, stating that there should be “[n]o change in the reference condition that
    would prevent the full support of aquatic biota, wildlife, or aquatic habitat uses.” VWQS § 3-
    04(B)(4). In a high quality habitat, “[b]iological integrity is maintained and all expected functional
    groups are present.” Id. The habitat supports and protects “all life-cycle functions, including
    overwintering and reproductive requirements.” Id. A reference condition is:
    [T]he range of chemical, physical, and biological characteristics of waters minimally
    affected by human influences. In the context of an evaluation of biological indices, or
    where necessary to perform other evaluations of water quality, the reference condition
    establishes attainable chemical, physical, and biological conditions for specific waterbody
    types against which the condition of waters of similar waterbody type is evaluated.
    VWQS § 1-01(39).
    ANR asserts that high quality aquatic habitat is provided if 80% of the total maximum
    habitat observed is protected in a given waterbody. We owe deference to ANR’s interpretation
    of policy or terms when: “(1) that agency is statutorily authorized to provide such guidance; (2)
    complex methodologies are applied; or (3) such decisions are within the agency’s ‘area of
    expertise.’” In re Korrow Real Estate, LLC Act 250 Permit Amendment Application, 
    2018 VT 39
    ,
    ¶ 20 (citation omitted). As stated above, the Court gives deference to ANR’s interpretation of
    the VWQS, however, “the deference owed to agency determinations is not absolute.” Korrow
    26
    Real Estate, LLC, 
    2018 VT 39
    , ¶ 21 (citation omitted). “An agency’s authority to define terms
    within its statutory purview will be given deference unless that authority is applied ‘arbitrarily
    and capriciously’ such that it ‘give[s] rise to a violation of due process.’” 
    Id.
     (citing In re Woodford
    Packers, Inc., 
    2003 VT 60
    , ¶ 17, 
    175 Vt. 579
    ).
    In Vermont, the Secretary of ANR has the authority to review, establish, and revise the
    water quality standards. See 
    40 C.F.R. § 131.4
    (a) (giving states the authority to review, establish,
    and revise water quality standards); 10 V.S.A. § 1252(e) (requiring the Secretary of ANR to adopt
    water quality standards). As such, it is within ANR’s discretion to define the terms within the
    VWQS and within ANR’s area of expertise. High quality aquatic habitat, however, is undefined in
    the VWQS or in another formal document.
    At trial, ANR witnesses Jeff Crocker and Rod Wentworth testified regarding ANR’s
    interpretation of high quality aquatic habitat. ANR has often looked to the most limiting habitat
    approach, also known as the habitat optimization analysis, on the basis that this method is
    recommended in the relevant scientific literature. This sets habitat as a percentage of the
    maximum habitat observed, in this case, the maximum habitat observed within the relevant
    Gomez & Sullivan report for each respective facility, when determining what is high quality
    aquatic habitat.
    ANR offers that, based on scientific literature, 80% is a significant threshold level, because
    if less than 80% of the maximum habitat value observed is provided, species may experience
    various stressors.11 ANR suggests that this would lead to a decline in fish populations. No specific
    sources were cited or provided, however. Further, increasing the amount of habitat in any given
    waterbody does not necessarily correlate with an increase in actual fish populations. There are a
    variety of other factors that influence fish populations, including the various physical
    characteristics of a waterbody or other site-specific considerations.
    11
    Alternatively, MWL urges us to look to a comparison between available habitat and the natural flow
    regime. In support of this, MWL cites to the USGS PHABSIM guidebook, which cautions users against comparing
    current habitat to the maximum potential habitat observed because it is not tied to a natural flow regime. Further,
    they assert, comparison to a natural flow regime provides a more conservative estimate when, as in this case, the
    point at which habitat would decrease in relation to a lessened flow is unknown. We find their clarification helpful
    in guiding our understanding of what could be considered high quality aquatic habitat.
    27
    ANR’s approach is unwritten, not expressed in ANR’s policy, and is not considered an
    established practice of determining high quality aquatic habitat. Instead, this is an interpretation
    of what might be reasonably representative of high quality habitat based on professional
    judgment.
    Accordingly, we cannot afford ANR’s interpretation deference in this matter. To give this
    definition deference would result in the arbitrary and capricious application of the definition,
    threatening a violation of due process. See Korrow Real Estate, LLC, 
    2018 VT 39
    , ¶ 21. ANR has
    not provided a definition for “high quality aquatic habitat” in any statute, regulation, or any other
    ANR guidance documents, nor has there been any evidence that this is ANR’s established
    practice. See 
    Id. at n. 2
     (noting that ANR’s methodology was an established practice and
    therefore not arbitrary and capriciously applied).12
    For these reasons, we will not afford ANR deference in its definition of high quality aquatic
    habitat as habitat consisting of 80% or more of the maximum habitat observed. Therefore, for
    each of the three facilities, we consider the alternative definitions of high quality aquatic habitat
    provided by the parties, and the site-specific conditions in the relevant reaches, when
    determining whether high quality aquatic habitat is provided by the two different sets of water
    quality conditions advanced by ANR and MWL.
    IV.        Conditions to be imposed at the Project’s facilities.
    For a proposal to meet the VWQS, it must satisfy the Hydrology Policy (§ 1-02(E)),13 the
    Hydrology Criteria (§ 3-01(C)), the Anti-Degradation Policy, the water quality criteria for Class B
    waters (§ 3-04(B)), the DO and temperature requirements, and fully support designated uses (§
    3-04(A)).
    The VWQS also require protection of designated uses. Designated uses at the Project
    include: aquatic biota, wildlife, and aquatic habitat; aesthetics; public water supply; irrigation of
    12
    It has not been asserted that reaching this definition required the application of complex methodologies.
    If so, however, we would still decline to afford the definition deference, as MWL has provided credible evidence that
    the comparison between habitat and flow made by ANR is not recommended as the best practice. Therefore, this
    approach could be considered irrational and unreasonable. Korrow Real Estate, LLC, 
    2018 VT 39
    , ¶ 21.
    13
    Because the Hydrology Policy implicates the potential need for a phase-in period, we reserve discussion
    of the Hydrology Policy for Section VIII, Phase-In. Additionally, because the Hydrology Criteria are those criteria used
    to implement the Hydrology Policy, our discussion of compliance with the Hydrology Criteria at each facility occurs
    there as well.
    28
    crops and other agricultural uses; swimming and other primary contact recreational uses; and
    boating, fishing and other recreational uses. VWQS § 3-04(A)(1)-(6). At issue in the present
    appeal is the support of the designated uses of aquatic biota, wildlife, and aquatic habitat,
    aesthetics, and, to a certain extent, recreational uses.
    In the sections that follow, we consider each of the three facilities independently to
    evaluate what operational conditions are necessary to satisfy these different aspects of the
    VWQS. For each facility, we compare the requirements of ANR’s water quality certification
    against MWL’s new proposed conditions to identify which hew to the dictates of the VWQS.
    a. Morrisville Facility
    The current conditions at the Morrisville Facility primary bypass reach do not meet the
    VWQS. Presently, the minimum required bypass flow in the primary bypass reach is 12 cfs. As a
    part of the 2016 water quality certification, ANR imposed a condition requiring a minimum
    bypass flow of 70 cfs and one inch of water depth to be spilled over the dam spillway for aesthetic
    purposes. ANR argues in favor of these conditions on appeal. MWL proposes a flow of 43 cfs
    and no required spill over for aesthetic purposes. MWL does not dispute the conditions imposed
    by the 2016 water quality certification for Morrisville Facility’s secondary bypass reach. As such,
    the secondary bypass reach is not at issue in this appeal.
    For the reasons set forth below, we conclude that MWL’s proposal for the Morrisville
    Facility cfs flow complies with the VWQS. ANR’s proposed conditions exceed what is necessary
    to comply with the VWQS.
    Anti-Degradation Policy
    Under the Anti-Degradation Policy, “[e]xisting uses of waters and the level of water
    quality necessary to protect those existing uses shall be maintained and protected regardless of
    the water’s classification.” VWQS § 1-03(B)(1). Existing uses in the Lamoille Basin are identified
    as swimming, recreational boating, recreational fishing, and use as a public water supply. 2016
    Lamoille Tactical Basin Plan, p. 134. The Morrisville Facility primary bypass reach is not used as
    a public water supply. We therefore focus our analysis on recreational uses. 14
    14
    Recreational uses are also protected as designated uses. See VWQS § 3-04(A)(5)-(6) (naming swimming,
    other primary contact recreational, boating, fishing, and other recreational uses as designated uses).
    29
    At the Morrisville Facility there are limited opportunities for recreational uses within the
    bypass reach. First, the reach is very short and there is a large drop at the end of the reach, so
    recreational boating opportunities are limited. Second, the composition of the substrate within
    the reach does not support long-term fish habitat, so recreational fishing opportunities are
    limited. The 2016 water quality certification notes that there is an informal fishing location within
    the Morrisville Facility tailrace.
    The Court did not receive evidence suggesting that recreational boating or swimming
    occurs within the reach. Further, the Court did not receive evidence regarding whether either
    MWL’s proposal of 43 cfs or ANR’s certification requiring 70 cfs would support either of these
    uses.
    We conclude that MWL’s proposal of 43 cfs supports aquatic biota, wildlife, and aquatic
    habitat by providing high quality aquatic habitat, as set forth below. The proposed cfs is a
    significant improvement upon the current conditions in the bypass reach. Therefore, to the
    extent there is recreational fishing or recreational boating within the bypass reach, these uses
    are supported. The Court concludes that a flow of 43 cfs supports the recreational uses within
    the Morrisville Facility primary bypass reach.
    Water Quality Criteria for Class B Waters
    Waters must comply with the general water quality criteria as well as the applicable
    criteria for their class designation. VWQS § 3-01; VWQS § 3-04(B) (setting water quality criteria
    for Class B waters). There are eleven criteria general to all waters, VWQS § 3-01(B)(1)-(11), and
    seven criteria specific to Class B waters, see VWQS § 3-04(B)(1)-(7). Some of the seven criteria
    specific to Class B waters overlap with the general criteria. This appeal focuses on the water
    chemistry criteria of DO and temperature.
    Prior to MWL’s application for water quality certification, a study was conducted by
    Gomez & Sullivan at all MWL facilities regarding water quality in the respective locations. The
    2012 study aimed to understand the Project’s present and potential impact on water quality for
    both DO and temperature. Gomez & Sullivan Water Quality Monitoring Study Report, April 2013,
    p. 6. During the study, bi-monthly and continuous readings were taken of both DO and
    temperature levels and general environmental observations were taken.
    30
    At the Morrisville Facility, six sampling locations were identified in the impoundment at
    the thalweg,15 the dam site, the primary bypass reach, the tailrace, and downstream. The
    locations in the impoundment, primary bypass reach, and tailrace were continuously sampled
    from September to October of the study year. All other sites were periodically monitored from
    May to October of the study year.
    ANR was given the opportunity to comment on a draft sampling plan prior to the start of
    the study. ANR’s comments were then incorporated into the final study plan.
    Dissolved Oxygen
    At the Morrisville Facility, DO must be no less than 6 milligrams per liter (mg/l), with 70%
    saturation at all times. VWQS § 3-04(B)(2)(a). The Gomez & Sullivan Water Quality Monitoring
    Report concluded that the Morrisville Facility met the DO requirements in both the
    impoundment and bypass reach. Gomez & Sullivan Water Quality Monitoring Study Report, April
    2013, p. 45.
    At trial, ANR offered two reasons for why it disagrees with the Gomez & Sullivan study
    conclusions. First, ANR asserts that a flow of 43 cfs does not meet the VWQS for DO because at
    this rate there could be stagnation in the reach. This lack of circulation could cause a decrease
    in DO.
    Second, ANR disagrees with the times at which the continuous monitoring was conducted
    in the Gomez & Sullivan study because the monitoring equipment was not installed until
    September of the monitoring year. ANR practice, it asserts, is to conduct monitoring from July
    15 to September 15 of the monitoring year.
    ANR conducted an additional subsequent analysis of the water chemistry at the
    Morrisville Facility. ANR’s analysis consisted of viewing video of the flows at the facility to
    understand circulation in the reach. This was not done to supersede the results of the Gomez &
    Sullivan study but to provide ANR with assurances regarding the Gomez & Sullivan conclusions.
    The Court finds that ANR’s approach of viewing videos of the flows is not a scientifically reliable
    15
    Black’s Law Dictionary notes that “thalweg” is the Old German spelling of “talweg.” Thalweg, BLACK’S LAW
    DICTIONARY (5th ed. 1979). It defines “talweg” as, in relevant part, “meaning the middle or deepest or most navigable
    channel.” Talweg, BLACK’S LAW DICTIONARY . The definition notes that it is frequently used as related to water
    boundaries. Id. Here, however, we take it to denote the middle or deepest location in the impoundment.
    31
    method of determining DO in a waterbody. Further, we note that ANR received the Gomez &
    Sullivan draft sampling plan and was afforded the opportunity to comment on the draft. ANR’s
    comments were then incorporated in the final sampling plan. Because the Gomez & Sullivan
    study afforded ANR this opportunity, it is unclear why ANR is now asserting that the study
    contains a “fatal flaw.” ANR Post-Trial Brief, p. 77. We conclude the Gomez & Sullivan water
    quality study sampling was sufficient to reach the conclusions therein.
    Based upon the evidence before the Court, the Morrisville Facility is meeting the DO
    standards in the impoundment and the tailrace at its current flow of 12 cfs. Therefore, we are
    unconvinced that a significantly increased flow, improving water circulation within the reach and
    providing increased opportunity for water aeration by increasing water flow over the crest of the
    dam, will somehow decrease the DO in the reach. For these reasons, MWL’s proposal of a
    minimum flow rate of 43 cfs meets the DO requirement of the VWQS.16
    Temperature
    At the Morrisville Facility, the current total allowable temperature increase above the
    ambient temperature is one-degree Fahrenheit. VWQS § 3-01(B)(1)(b). The Gomez & Sullivan
    Water Quality Monitoring Study Report concluded that the temperature in the reach and
    impoundment met this standard under existing conditions.
    ANR raises the same concerns regarding the sampling data within the Gomez & Sullivan
    water quality study here as raised with respect to DO discussed above. For the same reasons,
    the Court concludes the Gomez & Sullivan water quality study sampling supports the conclusions
    reached therein.
    As stated above, an increase in flow from 12 cfs to 43 cfs would significantly improve
    circulation in the reach. In the context of temperature, this increased flow limits the likelihood
    of the sun warming stagnant waters, a common cause of increased temperatures in a waterbody,
    even though the water’s surface area within the reach will be increased. Further, the reach
    generally meets the temperature requirement of the VWQS under current conditions. The
    16
    Our conclusion is further supported by ANR’s assertion that flows over the 7Q10 flow, representative of
    a drought flow, usually maintain the DO in a waterbody to a level suitable for aquatic biota and, therefore, comply
    with the water chemistry requirements. Both the flow included in the 2016 water quality certification and the flow
    proposed by MWL exceed the 7Q10 flow.
    32
    exception of this being the July temperature readings in which there was an approximately two-
    degree Celsius difference between upstream and downstream conditions (the downstream
    conditions were cooler than the upstream conditions). July, as many parties stated at trial, is a
    dry month where temperature can be a concern.
    A flow of 43 cfs will provide a significant improvement in flow and circulation within the
    reach, helping the facility to meet the temperature requirements throughout the year and
    significantly improving conditions during the dry summer months. Like DO, ANR asserts that
    flows over the 7Q10 flow in a waterbody usually maintain a temperature to a level suitable for
    aquatic biota and, therefore, comply with the water chemistry requirements. A flow of 43 cfs
    exceeds the 7Q10 flow.
    We conclude, therefore, that a flow of 43 cfs will meet the temperature requirement of
    the VWQS.
    Designated Uses
    Designated uses in Class B waters include: aquatic biota, wildlife, and aquatic habitat;
    aesthetics; public water supply; irrigation of crops and other agricultural uses; swimming and
    other primary contact recreational uses; and boating, fishing and other recreational uses. VWQS
    § 3-04(A)(1)-(6). The waters at the Morrisville Facility are not used as a public water supply or
    for irrigation or agriculture. We address recreational uses above in the context of existing uses.
    Thus, we review the aquatic biota, wildlife, and aquatic habitat use and the aesthetic use here.
    Aquatic Biota, Wildlife and Aquatic Habitat
    High quality aquatic habitat must be available to support aquatic biota, wildlife, and
    aquatic habitat. VWQS § 3-04(A)(1). For the reasons set forth below, high quality aquatic habitat
    will be provided by MWL’s proposal of a minimum bypass flow of 43 cfs.
    The Morrisville Facility’s bypass reach is relatively short, approximately 400 feet long. The
    substrate of the reach is primarily bedrock, which does not typically support aquatic plant life,
    macroinvertebrate habitat, or fish spawning habitat. 17 An increase in flow would not improve
    17
    There is the potential for macroinvertebrates to spill over the dam into the reach, much like fish would,
    but the reach itself would not support macroinvertebrate habitat.
    33
    these physical habitat constraints. Because of this and the low flow currently in the reach, there
    is presently little fish and aquatic habitat.
    On the right side of the tail race there is an area where water pools. At the end of the
    reach, there is an approximately 15-foot drop. This drop discourages fish from moving up the
    bypass reach from the Lamoille River. It is highly unlikely that a fish would move up the bypass
    reach from the Lamoille River because of the elevation of the drop and, at high flows, the speed
    of the water. Fish only move through the bypass reach when moving over the crest of the dam
    into the reach and then, if they continue, over the drop and into the main stem of the Lamoille
    River.
    Because of the composition of the bypass’ substrate, food production is not supported
    and there is inadequate spawning habitat in the reach. Therefore, most fish will use the reach in
    a transient nature. Most fish will not linger in the reach because of its lack of food resources, but
    they may use the reach to rest.18
    Appropriate fish habitat includes cover in the form of adequate water depth, substrate
    features, and turbulence on the surface of the water. The combination of the three forms of
    cover obscures the bottom of the reach, which provides a place to rest away from predators.
    Additionally, appropriate fish habitat includes connectivity within the reach so that fish can safely
    move from the dam to the Lamoille River.
    MWL’s consultant Gomez & Sullivan, in 2012, designed methodology to study flow and
    aesthetic impacts of the Project. ANR’s comments were incorporated into this study, which was
    conducted in the Fall of 2012.
    At the Morrisville Facility, within the primary bypass reach, flow demonstrations and
    observations were performed at 4.5 cfs, 21 cfs, 59 cfs, and 91 cfs.19 Considerations of the flow’s
    18
    We note that no data was provided regarding whether fish stay in the bypass reach on a long-term basis.
    We do, however, find credible MWL expert’s assessment of the impacts the composition of the reach would have
    on fish staying in the reach long-term. Specifically, the substrate in the reach and its inability or unlikelihood of
    providing macroinvertebrate, aquatic plant life, and fish spawning habitat. Therefore, while it is theoretically
    possible for a fish to remain in the reach long-term, it is highly unlikely.
    19
    While we have been provided with clear references for 4.5 and 21 cfs, representing a leakage flow and a
    1-inch spill, respectively, descriptors of what 59 and 91 cfs represent are less clear. The relevant studies state that
    these flows represent 0.2 and 0.4 cfsm, respectively. We understand “cfsm” to stand for cubic feet per second per
    square mile but have not been provided with any further understanding of these measurements.
    34
    effects on downstream habitat connectivity, circulation, cover, and temperature were weighed.
    The percentage of usable habitat for the target species, adult and juvenile rainbow trout, brook,
    and brown trout, at each flow were calculated. These results are habitat-flow, or habitat supply,
    curves.
    MWL consultants performed additional analysis of the primary bypass reach. Meddie
    Perry created a flow-energy model to evaluate how changes in flow over time relate to
    hydroelectric generation. Mr. Perry combined the results of the flow-energy model and the
    habitat-flow curves to develop a flow and habitat duration analysis that evaluated the availability
    of habitat over time under different flow scenarios.
    Additionally, MWL consultant Mary Nealon aided Mr. Perry in his analysis of the
    Morrisville Facility. Ms. Nealon made general habitat observations. Ms. Nealon and Mr. Perry
    used habitat supply information from the Gomez & Sullivan study, USGS streamflow data from
    the USGS streamflow gauging station in Johnson, Vermont, and project operation information to
    perform a habitat time series analysis. This habitat time series analysis incorporated habitat
    supply curves from the Gomez & Sullivan flow study. The analysis created habitat and flow
    relationships for target species at specific life stages. MWL experts then created the habitat time
    series, which reflects how habitat varies according to the flow value and over time, specifically
    as related to the frequency and duration at which those flows occur. The original analysis did not
    include rainbow trout. An updated time series analysis was conducted which analyzed rainbow
    trout. Both Mr. Perry and Ms. Nealon testified that their overall conclusions regarding the facility
    were unchanged by the updated time series analysis.
    Based upon all of this information, MWL concluded that a 43 cfs flow was appropriate for
    the Morrisville Facility.
    At 43 cfs, as stated above, the water movement supports the DO and temperature
    standards which aid high quality fish habitat. A flow of 43 cfs provides fish with adequate cover
    both in terms of water depth and turbulence, as well as bypass substrate. Additionally, habitat
    connectivity and adequate depth for passage are supported at the 43 cfs flow rate, as shown by
    the Gomez & Sullivan report. Gomez & Sullivan Morrisville Bypass Flow Study Report, p. 13
    (concluding that all flows observed provided adequate habitat connectivity and depth for
    35
    downstream passage, though a leakage flow provided difficult passage, and all flows above the
    leakage rate performed better).
    We adopt the most limiting habitat approach when evaluating whether a proposed flow
    rate supports high quality fish habitat. The most limiting species is adult rainbow trout. At 43 cfs,
    67% of the maximum adult rainbow trout habitat observed is provided. 20 When analyzing the
    habitat provided at this flow relative to the habitat provided by a natural flow regime, on an
    annual basis, 79% of habitat is provided for adult brook and brown trout, 70% is provided for
    adult rainbow trout, 94% is provided for juvenile brook and brown trout, and 76% is provided for
    juvenile rainbow trout. This results in an overall weighted average of 80% of habitat provided by
    a 43 cfs flow relative to a natural flow regime.
    ANR raised concerns with the fact that MWL experts combined target organisms to reach
    a weighted average. This concern is based in the fact that it is unclear whether specific species
    or life stages are given more or less value in the weighting. While we note the concern, MWL has
    provided averages for each species and their life stages separate and apart from the overall
    weighted average, as noted above.
    Further, ANR asserts that MWL included flows in the habitat time series analysis that
    would be uncontrollable, essentially naturally occurring high and low flows, which occur
    approximately 25% of the time. ANR asserts that these uncontrollable flows should not be
    factored into the habitat analysis. We do not find the inclusion of this data within the habitat
    time series analysis to be in error, largely because these uncontrollable flows do occur, even if
    infrequently, and do affect habitat within the bypass reach.
    ANR asserts that 70 cfs, the flow condition imposed by the water quality certification, is
    necessary to provide high quality aquatic habitat. ANR bases this flow on the most limiting
    habitat approach, and the fact that this flow provides 80% of the maximum habitat observed in
    the Gomez & Sullivan study. We again note that this approach is not ANR’s policy, but an
    interpretation of what could be considered high quality aquatic habitat.
    20
    However, 73% of habitat is provided for juvenile rainbow trout, 94% is provided for juvenile brook and
    brown trout, and 78% is provided for adult brook and brown trout.
    36
    At 70 cfs, under the most limiting habitat approach (with adult rainbow trout as the most
    limiting species), 83% of the maximum habitat observed is provided. Further, 86% is provided
    for juvenile rainbow trout, 97% is provided for juvenile brook and brown trout, and 90% is
    provided for adult brook and brown trout.
    Relative to a natural flow regime, instead of the maximum habitat observed, 70 cfs
    provides 90% of habitat for adult brook and brown trout, and 97% for juveniles. We do not have
    data comparing habitat provided for juvenile and adult rainbow trout at 70 cfs to a natural flow
    regime.
    In the bypass reach, the rough bedrock substrate, the depth of the pool, and the
    turbulence provided by the dam provide cover for fish when moving through the reach. There is
    no spawning habitat available and there is a highly unlikely chance that significant food sources
    would be supported in the reach at any flow. 43 cfs provides 67% of the maximum habitat
    observed for the most limiting species. We have not been provided evidence regarding the
    significance of a 13% decrease in habitat value in relation to a most limiting species approach.
    Further, 70% of habitat is provided as compared to a natural flow regime and 80% of habitat is
    provided as an overall average. We find that using a natural flow regime approach when
    determining high quality aquatic habitat is reasonable considering the VWQS. See VWQS § 1-
    02(F) (requiring preservation of the natural flow regime “to the extent practicable.”); VWQS § 2-
    02 (considering flow values used to determine compliance with VWQS criteria in relation to the
    natural flow regime); VWQS § 3-01(C)(1)(c) (determining maintenance of flow characteristics in
    Class B waters when changes are made to the natural flow regime). 21
    For all these reasons, we conclude that 43 cfs provides high quality aquatic habitat in the
    Morrisville Facility primary bypass reach.
    Aesthetics
    Class B waters shall be managed to maintain the designated use of aesthetics. VWQS § 3-
    04 (A)(2).    Aesthetics include the “water character, flows, water level, bed and channel
    characteristics, exhibiting good aesthetic value and, where attainable, excellent aesthetic value
    21
    We again note MWL’s assertion that the USGS PHABSIM guidebook cautions users from comparing
    habitat to the maximum observed because it is not tied to a natural flow regime. This guidebook was not, however,
    introduced into evidence, though both Ms. Nealon’s and Mr. Perry’s expert reports cite to the document.
    37
    based on the Water Management Type designation.” Id. Where a Class B water has not been
    assigned a water management type, as is the case here, the water must have “a quality that
    consistently exhibits good aesthetic value.” VWQS § 3-04(B)(6)(d).
    The parties agree that the current conditions of the Morrisville Facility do not provide
    good aesthetic value when viewing the dam or the bypass reach. ANR asserts that a one-inch
    spill of water over the dam and a flow of 70 cfs are required to meet the VWQS. MWL disagrees,
    offering that a spill requirement is not necessary and that a flow of 43 cfs will provide good
    aesthetic value. It is noted that a flow of 43 cfs would result in approximately two inches of
    spilled water at most times, however, during winter freeze conditions there may be no spill at
    this flow rate. We consider the parties’ offers.
    Aesthetic evaluations of the 4.5 cfs, 21 cfs, 59 cfs, and 91 cfs flows were conducted in the
    Gomez & Sullivan Aesthetic Flow Study.22 At the Morrisville Facility, four individuals observed
    four different flow characteristics in the bypass reach and then the team evaluated the aesthetic
    quality of the flows. Because of the limited public visibility of the primary bypass reach, only one
    vantage point of the reach was utilized. This vantage point was located on the bridge over the
    bypass reach. This study concluded that, at the primary bypass reach, a one-inch spill over the
    crest of the dam at a flow of 21 cfs in the channel provided good aesthetic value.
    In 2017, Mr. Perry conducted an independent aesthetic evaluation of additional
    demonstration flows of 12, 28, 43, and 70 cfs at the Morrisville Facility. Mr. Perry concluded that
    a 43 cfs flow would provide good aesthetic value at the primary bypass reach. This flow would
    provide for approximately two inches of spillage over the dam.
    Based upon the evidence provided by the parties, we are unconvinced that a one-inch
    spill should be required at the Morrisville Facility to satisfy the VWQS aesthetic requirements.
    The dam and its bypass reach are visible only to a limited degree. While the dam itself is quite
    large, one must be on the bridge over the primary bypass reach, located on B Street, to view it.
    Otherwise, public visibility is extremely limited.             Further, complying with a one-inch spill
    requirement may be impractical in the winter months when the impoundment behind the dam
    is frozen. Therefore, we conclude that a minimum spill requirement is not warranted, and we
    22
    These flows represent the same flows scenarios as discussed in Footnote 19.
    38
    turn our focus to what flow rate should be required to provide good aesthetic value of the dam
    and the reach.
    At 43 cfs, water crests and falls over a majority of the dam, resulting in a veil of water over
    its concrete face. This spillage will result in approximately two inches of water being spilled over
    the dam. Downstream, this flow results in water pooling and showing some exposed ledge and
    rocky features as well as visible flows. At 70 cfs, there is a full veil of water cresting over the dam,
    which is slightly thicker than that at 43 cfs. In the bypass reach, at 70 cfs, the channel is largely
    full and less of the bed and channel characteristics are apparent.
    ANR asserts that the methodology employed by Mr. Perry was improper because Mr.
    Perry conducted the analysis alone. This concern does little to devalue his conclusions. The
    results of the Gomez & Sullivan aesthetic flow study, conducted by a team of four, concluded
    that a flow of 21 cfs in the primary bypass reach, coupled with a one-inch spill over, provided
    good aesthetic value. Mr. Perry’s conclusion, and MWL’s proposal, increases the flow rate and
    provides for greater spillage.
    We therefore conclude that a flow of 43 cfs meets the aesthetic requirements of the
    VWQS for Class B waters. This flow provides good aesthetic value both at the dam and within
    the bypass reach. A flow of 70 cfs goes beyond what is necessary to provide good aesthetic value
    in the bypass reach pursuant to VWQS §§ 3-04(A)(2) and 3-04(B)(3)(d). Further, a condition
    requiring one-inch of spilled water over the crest of the dam is unnecessary due to the limited
    public visibility of the dam and the bypass reach and the impracticability of complying with the
    condition year-round. We find that declining to adopt a minimum spillage condition is further
    supported by the fact that a flow of 43 cfs will result in approximately two inches of spillage over
    the dam during non-freeze conditions.
    b. The Morrisville Facility as an existing use pursuant to VWQS § 1-03(B)(1)(d)
    The parties disagree as to whether the hydroelectric generation at the Morrisville Facility
    is an existing use pursuant to VWQS § 1-03(B)(1)(d) and, therefore, subject to the protection of
    the Anti-Degradation Policy. While this issue is not explicitly raised in any parties’ Statement of
    Questions, the parties agree that this issue is intrinsic to the Statement of Questions. See In re
    Jolley Assocs., 
    2006 VT 132
    , ¶ 9, 
    181 Vt. 190
    . Thus, the issue is appropriately before the Court in
    39
    this de novo appeal. In the discussion that follows, we affirm hydroelectric generation as an
    existing use. We acknowledge that this finding is immaterial with regards to the conditions to be
    implemented at the Morrisville and Green River Facilities, because MWL’s proposed conditions
    for both facilities satisfy the VWQS regardless of whether the facilities are categorized as existing
    uses or not.23 But because of the emphasis the parties have placed on the question, and their
    extensive briefing on the subject, we address it here as well.
    Existing uses are entitled to protection regardless of the water’s classification. VWQS § 1-
    03(B)(1). In determining existing uses to be protected, ANR must consider, in part, “the use of
    the water for . . . commercial activity that depends directly upon the preservation of an existing
    high level of water quality.” VWQS § 1-03(B)(1)(d). The parties do not debate the fact that
    hydroelectric generation at the Morrisville Facility is a commercial activity. Therefore, our
    analysis turns on whether hydroelectric generation depends upon “an existing high level of water
    quality.” Id.
    MWL asserts that hydroelectric generation depends on a high level of water quality due
    in large part to its reliance on a river’s hydrology and flow. This is because, at any given time, the
    flow in a river or the water level in a reservoir must be sufficient to support generation. In
    addition, total suspended solids and other solids, including refuse and debris, as well as scum or
    sludge, must be limited. If they are not, hydroelectric intake systems can clog, which would
    require generation to cease or slowdown to remove the blockage. Further, turbidity, as
    associated with sediment, can wear down the blades of the hydroelectric turbines, decreasing
    generation efficiency and causing the facility to require more water to generate at equivalent
    rates, thus impeding overall generation. See VWQS § 3-01(C)(1) (setting the Hydrology Criteria,
    flow changes as related to the natural flow regime must provide flow characteristics that fully
    support uses and comply with water quality criteria); VWQS § 3-01(B)(4)-(5) (regulating sludge,
    solid refuse, settleable solids, floating solids, oil, grease, scum, or TSS as general water quality
    criteria); VWQS § 3-01(B)(5) (regulating TSS as water quality criteria as related to Class B waters);
    VWQS § 3-04(B)(1) (regulating turbidity as water quality criteria in Class B waters). For these
    23
    This is not so for the Cadys Falls Facility, where its classification as an existing use does have
    implications for the conditions it must meet under the VWQS, as discussed in Section IV.d.
    40
    reasons, MWL asserts that hydroelectric generation is an existing use as a commercial activity
    reliant on a high level of water quality pursuant to VWQS § 1-03(B)(1)(d).
    ANR and VNRC/TU disagree, arguing that because a hydroelectric facility could operate in
    waters having adequate flow but impacted by phosphorus or nitrogen, it cannot be considered
    reliant on a high level of water quality.24 Additionally, they assert that because the waters are
    not currently high quality the section does not apply.25 Lastly, ANR and VNRC/TU assert that
    hydrology, particularly as it relates to flow and volume, should not be considered as factors of
    water quality in the interpretation of VWQS § 1-03(B)(1)(d).
    The Court gives “substantial deference to an agency’s interpretation of its own
    regulations,” here, the VWQS. In re ANR Permits in Lowell Mountain Wind Project, 
    2014 VT 50
    ,
    ¶ 15, 
    196 Vt. 467
     (citing In re Peel Gallery of Fine Arts, 
    149 Vt. 348
    , 351 (1988)). “Absent a clear
    and convincing showing to the contrary, decisions made within the expertise of such agencies
    are presumed correct, valid and reasonable.” In re Johnston, 
    145 Vt. 318
    , 322 (1985). Parties
    challenging ANR’s interpretation “bear the burden of showing that ANR’s interpretation is wholly
    irrational and unreasonable in relation to its intended purpose.” ANR Permits, 
    2014 VT 50
    , ¶ 17
    (citations omitted); see also Plum Creek Me. Timberlands, LLC v. VT. Dep’t of Forests, Parks &
    Recreation, 
    2016 VT 103
    , ¶ 28, 
    203 Vt. 197
    ; In re Costco Stormwater Discharge Permit, 
    2016 VT 86
    , ¶ 5, 
    202 Vt. 564
    .
    We do not defer to ANR’s interpretation that hydroelectric generation is not an existing
    use because it does not require a high level of water quality pursuant to VWQS § 1-03(B)(1)(d).
    ANR’s position is based partially on the premise that flow rate and water volume are not features
    24
    ANR and VNRC/TU suggest that reliance on “an existing high level of water quality” means reliance on water that
    is not impaired in any way. We decline to adopt such a narrow definition of high quality water. An activity can
    depend on water that is of high quality in one respect, while being negligibly affected by a contaminant it may
    carry. For example, the Project’s hydroelectric activity would be significantly impaired by water degraded by TSS,
    scum, or sludge. And while high loads of phosphorus or nitrates would have little to no consequence for
    generation, the Project still requires water of high quality with regards to these other potential impairments.
    25
    The parties take up the “existing” modifier in “existing high level of water quality” to say that the Project
    operates without a problem at present, despite the downstream waters failing to meet the VWQS, so it is not an
    activity requiring an existing level of high quality water. This view puts the cart before the horse, or, better stated,
    the bypass reach before the dam. As a commercial activity, hydroelectric generation depends on an input of high
    quality waters, coming from upstream of the facility. It does not “depend directly[]” on the quality of downstream
    waters. There is no evidence before the Court showing that any of the Project’s facilities are operating
    satisfactorily despite an input of low quality water from upstream.
    41
    of water quality, so, while hydroelectric generation is dependent on certain flow rates, it is not
    dependent on an aspect of water quality. This interpretation of VWQS § 1-03(B)(1)(d) is
    unreasonable, for the following reasons:
    First, hydrology as it relates to flow, water volume, and water quality, specifically to the
    implementation of the Hydrology Policy and Hydrology Criteria to support designated uses, are
    central issues in this appeal. The Court has received extensive testimony regarding the impacts
    that hydrology and flow have on water quality and compliance with the VWQS. This expert input
    supports a finding that flow rate is an integral component in any assessment of water quality.
    Second, the Hydrology Policy expressly considers flow interruptions and fluctuations
    because of existing and new dams or control structures when determining conditions to preserve
    the natural flow regime. VWQS § 1-02(E)(1). The VWQS themselves conceive of flow as a feature
    of water quality.
    Third, the United States Supreme Court has held that the distinction between water
    quality and quantity is “an artificial distinction.” PUD No. 1 of Jefferson Cty. v. Washington Dept.
    of Ecology, 
    511 U.S. 700
    , 719 (1994) (interpreting the Clean Water Act as part of a 401
    certification). The Court noted that the Clean Water Act includes a broad definition of pollution.
    
    Id.
     (citing 
    33 U.S.C. § 1362
    (19)). Further, “[i]n many cases, water quantity is closely related to
    water quality.” 
    Id.
    Adequate hydrology and the physical impacts of water are considered when determining
    adequate water quality in the other contexts at issue in this appeal. We see no reason for
    excluding these issues in the context of VWQS § 1-03(B)(1)(d). We therefore consider hydrology
    when determining if there is a high level of water quality.
    Finally, to adopt the interpretation proposed by ANR would render the Anti-Degradation
    Policy, particularly § 1-03(B)(1)(d), unnecessary and meaningless. To read the policy so narrowly
    would result in a failure to provide meaningful protection to uses that are existing. 26
    26
    We further decline to adopt ANR and VNRC/TU’s assertion that, because hydroelectric generation tends
    to degrade water quality, it cannot be an existing use. To do so would ignore the reality of the 401 certification’s
    role. It is uncontested that the present conditions of the relevant waters do not comply with the VWQS. However,
    the central issue in this appeal is reaching a set of certification conditions that result in MWL’s compliance with the
    necessary standards. Therefore, while unregulated hydroelectric generation may degrade a waterbody, the
    42
    Further, ANR and VNRC/TU argue that because hydroelectric generation was not
    identified as an existing use in the basin planning process and has never been determined to be
    an existing use before, it must be precluded from protection under the Anti-Degradation Policy.27
    Existing uses may be identified either through the basin planning process, or on a case-
    by-case basis “during the consideration of an application.” VWQS §§ 1-03(B)(1). Our role, in
    conducting our de novo review, is to determine, in part, the Project’s compliance with the VWQS.
    See In re Morrisville Hydroelectric Project Water Quality Certification, No. 103-9-16 Vtec, slip op.
    at 4-5 (Vt. Super. Ct. Envtl. Div. Jun. 13, 2017) (Walsh, J.) (citing 10 V.S.A. § 8504(h)). It is therefore
    within the scope of our review to determine if hydroelectric generation is an existing use
    pursuant to VWQS § 1-03(B)(1)(d). For hydroelectric generation to be operational and efficient,
    a waterbody must have adequate hydrological characteristics in the form of flow and volume, it
    must lack physical impediments such as debris, sludge, various solids, and turbidity. While the
    Morrisville Facility can operate if a water is impaired for some criteria regulated by the VWQS,
    the waters must be high quality in the areas addressed above. For these reasons, we conclude
    that hydroelectric generation at the Morrisville Facility is an existing use under VWQS § 1-
    03(B)(1)(d) as a “commercial activity that depends directly on the preservation of an existing high
    level of water quality.”28
    c. Cadys Falls Facility
    Current conditions at the Cadys Falls Facility bypass reach do not meet the VWQS. Under
    its current license, MWL is not required to pass any flow into the reach. Therefore, the only flow
    permitting regime itself stands for the proposition that, with the proper and proportional conditions, hydroelectric
    generation will not degrade water quality.
    27
    VNRC/TU also point to two previous water quality certifications for hydroelectric facilities: a Winooksi
    River project from 1993 and a Deerfield River project from 1995. In the case of the both projects, they assert that
    ANR included in a public comment a statement that the hydroelectric generation projects can degrade water quality
    and, therefore, are not existing uses.
    Both final water quality certifications were not appealed. Further, neither the responses to public comment
    nor the subsequent certifications were offered into evidence. A response to public comment regarding an
    unappealed certification issued over 20 years ago does not have precedential authority over the Court.
    28
    We note that there have been no Vermont cases addressing the applicability of this section to
    hydroelectric generation projects. Maine, however, has addressed the issue as related to Maine’s Anti-Degradation
    Policy. S.D. Warren Co. v. Maine Dep’t of Envtl. Prot., 
    2004 WL 143367
    , at *5 (Super. Ct. Me. May 4, 2004). The
    Maine Court concluded that hydroelectric generation was an existing use that must be maintained and protected
    pursuant to the Anti-Degradation Policy. 
    Id.
     The Court further concluded that an approximately 15% reduction in
    energy generation at the facility still supported the existing hydroelectric use. 
    Id.
    43
    within the reach is leakage, resulting in a flow of approximately 5.5 cfs. As part of the 2016 water
    quality certification, ANR imposed a minimum bypass flow of 100 cfs and one-inch of water to be
    spilled over the dam crest for aesthetic purposes. In this appeal, MWL proposes a minimum
    bypass flow of 65.5 cfs. MWL does not propose a requirement that water be spilled over the
    crest of the dam. For the reasons set forth below, we adopt MWL’s proposal.
    Anti-Degradation Policy
    Under the Anti-Degradation Policy, “[e]xisting uses of waters and the level of water
    quality necessary to protect those existing uses shall be maintained and protected regardless of
    the water’s classification.” VWQS § 1-03(B)(1). Existing uses in the Lamoille Basin are identified
    as swimming, recreational boating, recreational fishing, and use as a public water supply and
    irrigation. 2016 Lamoille Basin Plan, p. 134. The Cadys Falls Facility bypass is not used as a public
    water supply. We therefore focus our analysis on recreational uses.29
    The 2016 water quality certification recognizes that there are three formal recreational
    sites associated with the Cadys Falls Facility: a boat launch within the impoundment with
    associated parking spaces, a portage take-out within the impoundment with two associated
    parking spaces, and a put-in 1,500 feet downstream from the dam. 2016 Water Quality
    Certification, ¶¶ 178-79. We further note that in the Lamoille Basin Plan recreational fishing at
    the Cadys Falls Bridge is recognized as an existing use. Lamoille Basin Plan, Appendix F, Table F3,
    p. 200.
    At trial, we were provided with little evidence regarding the impact on existing
    recreational uses of any proposed flow at the Cadys Falls Facility bypass reach. This may be
    because in its current flow regime only 5.5 cfs is passed through the reach and recreational uses
    such as boating, fishing, or swimming, would only be supported when natural flows allowed.
    There is a causal connection between increasing flow and improving support of
    recreational activities. As ANR pointed out in support of its conditions, an increase in flow will
    provide more consistent opportunities for recreational uses as compared to the intermittent
    opportunities presently available. This is also true in MWL’s proposal.
    29
    Recreational uses are also protected as designated uses. See VWQS § 3-04(A)(5)-(6) (naming swimming,
    other primary contact recreational, boating, fishing, and other recreational uses as designated uses).
    44
    ANR asserts that MWL’s proposed 65.5 cfs does not meet the Anti-Degradation Policy,
    because MWL takes into consideration the commercial use of hydroelectric generation in support
    of less high quality aquatic habitat. We have been provided with no evidence on why a flow of
    65.5 cfs would not support the enumerated existing uses of swimming, recreational boating, and
    fishing.
    We have credible evidence that flows of 65.5, 90, and 100 cfs will significantly improve
    the flow and amount of water in the reach.30 All three flows will provide consistent flows within
    the bypass reach that will provide recreational opportunities more frequently than the
    intermittent opportunities presently available.
    Further a flow of 65.5 cfs provides an overall weighted average of 63% of the maximum
    available habitat relative to a natural flow regime in the bypass reach. This is a significant
    improvement from the amount of habitat currently available at a leakage flow. This will further
    support more consistent recreational fishing opportunities within the reach than those currently
    available.
    Because a flow of 65.5 cfs will provide significantly improved flows and habitat within the
    bypass reach, we conclude that the flow will support the existing recreational uses in the bypass
    reach and therefore complies with this aspect of the Anti-Degradation Policy.
    Water Quality Criteria for Class B Waters
    As discussed above, waters must comply with the general water quality criteria as well as
    the applicable criteria for their class. VWQS § 3-01; VWQS § 3-04(B) (setting water quality criteria
    for Class B waters). While there are many water quality criteria for Class B waters, this appeal
    focuses on DO and temperature.
    Gomez & Sullivan, in connection with ANR and MWL, conducted a water quality
    monitoring study at the Project. The study’s goals and general approach are discussed above in
    Section IV.a. “Water Quality Criteria for Class B Waters.”
    At the Cadys Falls Facility, four sampling locations were identified. Two are located above
    the dam, at a thalweg station and farther upstream at the impoundment’s linear center, one
    30
    MWL expert Mary Nealon’s expert report provides a description of conditions at a flow of 90 cfs.
    45
    station is at the dam’s penstock tap, and the fourth is located downstream in the bypass reach.
    These locations were periodically monitored from May to October of the study year.
    Dissolved Oxygen
    At the Cadys Falls Facility, DO must be not less than 6 milligrams per liter (mg/l), with 70%
    saturation at all times. VWQS § 3-04(B)(2)(a). The Gomez & Sullivan Water Quality Monitoring
    Report concluded that the Cadys Falls Facility complied with the DO requirements of the VWQS
    under current conditions.
    For the same reasons discussed regarding the Morrisville Facility, a flow of 65.5 cfs will
    support the DO requirement of the VWQS. Even under the leakage conditions currently in place,
    the Cadys Falls Facility meets the DO requirements and the flow exceeds the 7Q10 drought flow.
    ANR asserts that the 2016 water quality certification flow of 100 cfs provides reasonable
    assurances that DO will be met.31 We conclude that a significantly increased flow of 65.5 cfs in
    waters already meeting DO standards provides adequate assurance of compliance.                                This
    increased flow improves water circulation and provides increased opportunity for water
    aeration.
    Therefore, we find that a flow of 65.5 cfs will meet the DO requirements of the VWQS.
    Temperature
    The total allowable increase above the ambient temperature is one-degree Fahrenheit at
    the Cadys Falls Facility. VWQS § 3-01(B)(1)(b). The Gomez & Sullivan Water Quality Monitoring
    Study Report concluded that the temperature at the facility met this standard under existing
    conditions.
    A flow of 65.5 cfs would significantly improve circulation within the reach. The increased
    flow limits the opportunities for water to stagnate and warm in the sun. Increasing the flow
    significantly to a rate above the 7Q10 drought flow, resulting in these improved water
    characteristics of flow and circulation, would provide assurances that the facility would continue
    to meet this standard.
    Therefore, we find a flow of 65.5 cfs will meet the VWQS temperature requirement.
    Designated Uses
    31
    ANR stated that a flow of 90 cfs could potentially support the DO and temperature criteria of the VWQS.
    46
    Designated uses in Class B waters include: aquatic biota, wildlife, and aquatic habitat;
    aesthetics; public water supply; irrigation of crops and other agricultural uses; swimming and
    other primary contact recreational uses; and boating, fishing, and other recreational uses. VWQS
    § 3-04(A)(1)-(6). Because the waters at the Cadys Falls Facility are not used as a public water
    supply or for irrigation or agriculture, and because recreational uses are discussed above, we
    analyze the aquatic biota, wildlife, and aquatic habitat use and aesthetic use here.
    Aquatic Biota, Wildlife, and Aquatic Habitat
    High quality aquatic habitat must be available to support aquatic biota, wildlife, and
    aquatic habitat. VWQS § 3-04(A)(1). For the reasons set forth below, we find MWL’s proposal of
    65.5 cfs does not provide high quality aquatic habitat.
    The Cadys Falls Facility operates in essentially a run-of-river mode and has a single 1600-
    foot bypass reach. The substrate in the reach is bedrock and a mixture of gravel and cobble. This
    substrate composition provides mixed habitat within the reach, including both riffle habitat and
    deeper areas. Unlike at the Morrisville Facility, there is no physical barrier preventing or limiting
    downstream passage of fish in the bypass reach.
    In 2012, Gomez & Sullivan conducted a study of flows at the Cadys Falls Facility
    concurrently with the studies at the Morrisville Facility, discussed above. Unlike the Morrisville
    Facility, the flow study at Cadys Falls was conducted using a modified PHABSIM methodology.
    This method uses transect information on the water’s depth, velocity, and substrate and aquatic
    habitat suitability index curves to create relationships between habitat and flow at the transects
    selected within the bypass reach.32
    Three transects were selected at various intervals within the reach. Flows of 48, 67, 98,
    139, and 163 cfs were measured. Target species were identified as macroinvertebrates and adult
    and juvenile brook, brown, and rainbow trout. Both ANR and MWL referred to this study and its
    results in reaching their respective flow proposals and determining if these flows support the
    designated use of aquatic biota, wildlife, and aquatic habitat use.
    32
    The modified method also uses field-based measurements as opposed to modeling to determine a
    transects’ hydraulic characteristics. Gomez & Sullivan, Cadys Falls Bypass Reach Flow Study Report, April 2013, p. 4.
    The study states that this method is preferred in reaches that are difficult to model or steep, like the Cadys Falls
    reach. Id.
    47
    Additionally, MWL expert Mary Nealon conducted an observational evaluation of the
    reach at the same locations at which Gomez & Sullivan placed transects and observed flows at
    54 and 100 cfs, and, in consultation with Mr. Perry, conducted a time series analysis. Ms. Nealon
    then concluded that a flow of 90 to 100 cfs would provide high quality aquatic habitat. At trial,
    Ms. Nealon recommended a flow of 90 cfs to meet this standard.
    MWL concedes that a flow of 65.5 cfs fails to provide high quality aquatic habitat in the
    Cadys Falls Facility bypass reach. This flow provides an overall weighted average of 63% of
    available habitat under a natural flow regime. MWL argues this does not make their proposal
    unviable, however, because a flow of 65.5 cfs would support the existing use of hydroelectric
    generation. A discussion of why hydroelectric generation is an existing use and, for that reason,
    why a flow that fails to fully support a designated use can still be imposed in compliance with the
    VWQS is provided in Section IV.d below.
    The parties agree that high quality habitat will be provided at a flow of 100 cfs. At this
    flow, under a natural flow regime, there is 79% of habitat available for adult brook and brown
    trout and 84% available for juveniles.33 We do not have data on the percent of habitat available
    at a flow of 90 cfs, either under a most limiting species theory or a natural flow regime theory.
    We appreciate MWL expert Mary Nealon’s testimony regarding flow and note her original
    recommended flow range of 90 cfs to 100 cfs. Without quantitative data regarding the amount
    of habitat provided at 90 cfs, however, we lack the adequate basis for determining whether a
    flow of 90 cfs would support high quality aquatic habitat within the bypass reach.
    Aesthetics
    Class B waters shall be managed to maintain the designated use of aesthetics. VWQS §
    3-04 (A)(2). Aesthetics include the “water character, flows, water level, bed and channel
    characteristics, exhibiting good aesthetic value and, where attainable, excellent aesthetic value
    based on the Water Management Type designation.” Id. Where a Class B water has not been
    assigned a water management type, as is the case here, it must have “water of a quality that
    consistently exhibits good aesthetic value.” VWQS § 3-04(B)(6)(d). The parties agree that the
    33
    We do not have data on the percent of habitat available under a natural flow regime for adult or juvenile
    rainbow trout or macroinvertebrates.
    48
    current conditions at the Cadys Falls Facility do not provide good aesthetic value at the dam or
    within the reach. ANR asserts that a one-inch spill of water over the dam and a flow of 100 cfs
    are required to meet the VWQS. MWL disagrees, arguing 65.5 cfs with no spilled water
    requirement will provide good aesthetic value. We agree with MWL’s proposal.
    Aesthetic evaluations of these flows were also conducted in a Gomez & Sullivan Aesthetic
    Flow Study. At the Cadys Falls Facility, five individuals observed three different flows of 27.7,
    77.6, and 133.3 cfs in the bypass reach. Three vantage points were assessed; one located on the
    bridge downstream from the dam, one within the reach, and one at the dam itself. The study
    concluded that a flow of 133.3 cfs provided good to good/excellent aesthetic value in the reach,
    whereas a flow of 77.6 cfs provided fair/good to good aesthetic value, depending on the vantage
    point. A flow of 27.7 cfs, however, did not provide good aesthetic value in the reach.
    MWL expert Mr. Perry conducted aesthetic flow demonstration observations at the site.
    Mr. Perry observed a flow of 53 and 100 cfs at three vantage points within the bypass reach, one
    viewing the dam, one viewing the bridge, and one in the middle of the reach.
    Through his observations, Mr. Perry concluded that a flow rate of 53 cfs provided good
    aesthetic value throughout the reach. Mr. Perry concluded that increasing the flow to 100 cfs
    did not improve the aesthetic quality.
    As with the Morrisville Facility, we are unconvinced that a one-inch spill should be
    required. The Cadys Falls Facility dam itself is not readily visible by the public and cannot be seen
    from Cadys Falls Road except for a limited view from the bridge over the bypass reach. The public
    also has a filtered view of the dam through trees on Needles Eye Road and Griggs Road. Access
    to the dam is only available by a gated road. Otherwise, public visibility is extremely limited.
    Further, complying with a one-inch spill requirement may be impractical in the winter months
    when the impoundment behind the dam is frozen. Finally, MWL’s proposal of 65.5 cfs will result
    in some spillage over the dam.
    Because the dam itself is largely out of the public’s sight, we conclude a one-inch spill is
    unnecessary and, in certain conditions, impossible or highly impracticable to comply with.
    Therefore, we turn our focus to what flow should be required to provide good aesthetic value in
    the reach.
    49
    MWL supports its proposal of 65.5 cfs by Mr. Perry’s aesthetic evaluation conclusions.
    Through his observations, Mr. Perry concluded that a flow rate of 53 cfs provided good aesthetic
    value throughout the reach. Mr. Perry asserts that with this flow a full veil of water falls over the
    crest of the dam, the bypass reach contains full water levels, and, within the reach, there are a
    variety of features such as pools, visible outcrops, riffles, and whitewater. Perry Report, p. 77.
    Further, the flow produces pleasant auditory effects such as rushing and babbling water. Id. Mr.
    Perry concluded that increasing the flow to 100 cfs did not improve these qualities. Id.
    ANR asserts we should give little credibility to Mr. Perry’s recommendation because of
    flaws within his flow observations. Largely, they assert, because he conducted his observations
    without the advice of ANR, without ANR staff present for the observations, and because Mr. Perry
    was alone without a team like that used during the Gomez & Sullivan aesthetic study, his
    conclusions are not credible. While we find that a team approach may provide a consensus in
    their recommendation, we are unconvinced that the failure to include ANR, either by seeking
    advice or inviting ANR staff to aid in the observations themselves, alone undermines the
    credibility of Mr. Perry’s observations.
    Mr. Perry was retained in this matter in 2014, prior to this litigation. The present appeal
    was filed on September 7, 2016, over a year before Mr. Perry conducted his aesthetic evaluations
    at the Cadys Falls Facility on October 12, 2017. We do not agree with ANR that a party’s expert
    reports and studies will lose credibility when they failed to invite or seek advice from an opposing
    party in a litigation, even when that opposing party has expertise in the area on which the report
    or study is conducted. We therefore afford his testimony on this matter the weight it deserves.
    The Van Sicklen Ltd/ P’ship, No. 4C1013R-EB, slip op. at 1 (Vt. Env. Bd. Sep. 28, 2001); In re
    Application of Lathrop Ltd. P’ship I, 
    2015 VT 49
    , ¶ 90, 
    199 Vt. 19
    .
    Further, the Gomez & Sullivan study did not observe flows between 27.7 cfs, which did
    not provide good aesthetic values, and 77.6 cfs, which provided fair/good aesthetic value
    depending on the vantage point. Therefore, Mr. Perry’s observations of a flow in that range are
    helpful in reaching a determination regarding what flow provides good aesthetic value.
    Mr. Perry credibly testified that a flow of 53 cfs provides good aesthetic value within the
    reach and would comply with VWQS § 3-04(B)(6)(d). Further, he credibly testified that increasing
    50
    the flow to 65.5 cfs would provide an increased assurance that good aesthetic value will be
    provided within the reach. Finally, he concluded that increasing the flow to 100 cfs does not
    significantly improve the aesthetics within the bypass reach beyond what is provided at lesser
    flows.
    As with the Cadys Falls dam itself, the bypass reach has few easily accessed vantage
    points. The public has a filtered view of the reach through trees on Needles Eye Road and Griggs
    Road and on the Cadys Falls Road bridge. Otherwise, public visibility is limited.
    Therefore, we conclude that a flow of 65.5 cfs, without a one-inch spill, will provide good
    aesthetic value in the Cadys Falls Facility bypass reach. A flow of 100 cfs, as included in the 2016
    water quality certification, exceeds that which is necessary to support good aesthetic value.
    For the reasons set forth below, the failure to provide high quality aquatic habitat in the
    Cadys Falls Facility bypass reach does not make MWL’s proposed 65.5 cfs flow unviable at the
    Cadys Falls Facility.
    d. The Cadys Falls Facility as an existing use pursuant to VWQS § 1-03(B)(1)(d)
    For the same reasons set out above with respect to the Morrisville Facility in Section IV.b,
    we conclude that hydroelectric generation at the Cadys Falls Facility is an existing use pursuant
    to VWQS § 1-03(B)(1)(d). Unlike at the Morrisville Facility, MWL’s proposal does not comply with
    the VWQS without recognizing hydroelectric generation as an existing use. The Court now must
    determine whether MWL’s proposal of 65.5 cfs complies with the VWQS with consideration to
    hydroelectric generation as an existing use.
    Waters “shall be managed to achieve and maintain a level of quality that fully supports .
    . . designated uses,” here, aquatic biota, habitat, and wildlife. VWQS § 3-04(A)-(1). “Existing uses
    . . . and the level of water quality necessary to protect those existing uses shall be maintained
    and protected.” VWQS § 1-03(B)(1).
    The proposals before the Court cannot support both the existing use of hydroelectric
    generation at the Cadys Falls Facility and the designated use of aquatic biota, habitat, and
    wildlife. MWL asserts that a flow of 65.5 cfs in necessary to support hydroelectric generation,
    while ANR asserts, and MWL concedes, that this flow would not provide high quality aquatic
    habitat. A flow of 100 cfs would provide high quality aquatic habitat but would result in a 21%,
    51
    or 713-megawatt hour (MWh), reduction in energy generation at the facility. MWL provided
    evidence, albeit thin, that at this reduced production rate they would have to shut down this
    facility. We conclude that imposing the 100 cfs flow would cause a reduction in energy generation
    that does not support the existing use of hydroelectric generation. We therefore must determine
    the proper balance between the two uses.
    MWL’s proposes a flow of 65.5 cfs. At this flow, 63% of the overall weighted average of
    habitat at a natural flow regime is provided. This flow results in a 35% increase in habitat
    availability as compared to the present leakage conditions.34 This flow will result in a 13%, or
    440-megawatt hour (MWh), reduction in energy generation.
    A flow of 100 cfs, as imposed by the 2016 water quality certification, provides high quality
    habitat. This flow would, however, result in a 21%, or 713 MWh, reduction in energy generation.
    A flow of 100 cfs, providing for an approximate 55% increase in available habitat and 21%
    reduction in generation, does not reasonably balance these two uses.
    The waters at the Cadys Falls Facility are not high quality. We therefore do not address
    the issue of a reduction of quality in existing high quality of waters. See VWQS § 1-03(C)(1)-(2).
    Instead, any flow imposed by the Court is improving water quality in a body that presently fails
    to meet the VWQS. Both proposals significantly improve water quality in the bypass reach, while,
    to differing degrees, degrading the existing use of hydroelectric generation at the Cadys Falls
    Facility.
    A flow of 65.5 cfs meets all relevant standards except for the aquatic biota, wildlife, and
    habitat use. A flow of 100 cfs provides high quality habitat but exceeds what is necessary to
    ensure compliance with the other VWQS and fails to comply with the Anti-Degradation Policy.
    The 100 cfs does not reasonably balance the uses within the Cadys Falls bypass reach. We must
    balance the requirements that waters “shall be managed to achieve and maintain a level of
    quality that fully supports . . . designated uses,” here, aquatic biota, habitat, and wildlife (VWQS
    34
    This percentage represents a comparison between habitat available for adult brook and brown trout.
    Data provided for adult and juvenile brook and brown trout show that 28% and 29%, respectively, of habitat available
    under a natural flow regime is available at the present leakage flow. We do not have data that includes the
    percentages of habitat available under the leakage flow for rainbow trout or macroinvertebrates.
    52
    § 3-04(A)-(1)), and maintain and protect “[e]xisting uses . . . and the level of water quality
    necessary to protect those existing uses.” VWQS § 1-03(B)(1).
    We conclude that a flow of 65.5 cfs reasonably balances the designated and existing uses
    at issue in the reach while complying with all other relevant sections of the VWQS as discussed
    above.35
    e. Green River Facility
    Current conditions at the Green River Facility do not meet the VWQS. Unlike the other
    facilities at issue in this appeal, the Green River Facility operates in store and release mode.
    Under existing conditions at the facility, a large reservoir is maintained behind the dam. From
    May to October, the reservoir is permitted a maximum fluctuation of one foot and the water
    levels must be managed for recreation and loon nesting habitat. During the winter, from
    December 30 to April 1, MWL is permitted have a winter drawdown of ten feet. The reservoir
    must be refilled by May 1. The minimum downstream flow year-round is 5.5 cfs. From May to
    October, the maximum generation flow is 160 cfs and from November to April the maximum
    generation flow is 283 cfs.
    As a part of the 2016 water quality certification, ANR imposed multiple conditions on the
    Green River Facility, both with respect to the reservoir and the downstream conditions. The
    conditions are generally seasonal.
    For the drawdown levels, ANR imposed, and argues for on appeal, a maximum reservoir
    fluctuation of 0.25 feet from June 1 to December 15. From December 16 to March 31, the winter
    drawdown, they would limit the drawdown to 1.5 feet. This drawdown would have to be refilled
    by May 1. Once the reservoir is refilled, MWL would be permitted a maximum reservoir
    fluctuation of 0.25 feet.
    35
    We note that ANR expressed concern with the use of the percentage of energy reduction as a means for
    determining if hydroelectric generation was supported. Again, while this issue has not been addressed in Vermont,
    Maine has addressed the issue as related to Maine’s Anti-Degradation Policy. S.D. Warren Co., 
    2004 WL 143367
    , at
    *5. In that case, the Court relied on the amount of energy reduced in determining whether the use was supported.
    
    Id.
     In doing so, the Court concluded that an approximate 15% reduction in energy generation at the facility still
    supported the use. 
    Id.
     We also conclude that the amount of energy generation reduced is a proper means of
    determining whether hydroelectric generation is supported.
    53
    With respect to flow conditions, ANR imposed multifaceted conditions based on the
    season and relevant drawdown in the reservoir. We summarize the conditions here. First, a
    minimum downstream flow of inflow, 5.5 cfs, or 7 cfs from June 1 to September 30 based on
    drawdown. From October 1 to December 15, a minimum downstream flow of inflow, 7 cfs, or 10
    cfs based on drawdown. From December 16 to March 31, flows of inflow, 6 cfs, or 8 cfs, based
    on drawdown. Finally, from April 1 to May 31, flows of 15 cfs, 30, cfs, 60 cfs, or inflow based on
    the refilling of the reservoir from the winter drawdown and general drawdown in the reservoir.
    Further, maximum generation flow conditions were also imposed by the 2016 water
    quality certification. From June 1 to December 15, ANR imposed a maximum generation flow of
    0 cfs, unless inflow is greater than 60 cfs, in which case, MWL must match the inflow. From
    December 16 to March 31, the maximum generation flow is 110 cfs or inflow if inflow exceeds
    110 cfs. Finally, from April 1 to May 31, a maximum generation flow of 0 cfs is imposed, unless
    inflow is greater than 60 cfs, in which case, a maximum of 60 cfs is required until the reservoir is
    refilled after the winter drawdown. Then, if inflows exceed 60 cfs, MWL generation flows match
    the inflow.
    MWL proposes alternative conditions at both the reservoir and downstream. From June
    1 to December 15, MWL proposes a maximum reservoir fluctuation of 0.25 feet. From December
    16 to March 31, MWL proposes a maximum winter drawdown of 6 feet, which will be determined
    annually based on snowpack measurements. The reservoir must be refilled by May 1. After refill,
    a maximum fluctuation of 0.25 feet is imposed.
    The minimum downstream flows proposed by MWL are somewhat simpler than those
    imposed by ANR’s water quality certification. From June 1 to September 30, a downstream flow
    of 7 cfs is imposed. From October 1 to December 15, MWL proposes a flow of 10 cfs. From
    December 16 to March 31, a minimum flow of 8 cfs will be imposed. Finally, from April 1 to May
    31, a minimum flow of 60/30 cfs would be released. In these seasons, if inflows are less than the
    enumerated flow rate, then downstream flows will match inflow. MWL asserts that natural high
    flows over 70 cfs will be passed downstream outside of the winter drawdown and spring refill
    period.
    54
    Maximum generation flows from June 1 to December 15 are set at 70 cfs or inflow, if
    greater. From December 16 to March 31, the maximum generation flow proposed is 160 cfs or
    inflow, if greater. Finally, from April 1 to May 31, maximum generation flows would be set at 60
    cfs, or inflow, if greater, but only if the reservoir exceeds the target water level for refill.
    As discussed in detail below, because MWL’s proposed flow regime supports the
    designated use of aquatic biota, wildlife, and aquatic habitat, and because it ensures that the
    VWQS’s DO and temperature standards will be met, we recognize this as the flow regime suitable
    for water quality certification. ANR’s proposed regime exceeds the requirements of the VWQS.
    However, because MWL’s proposed winter drawdown of six-feet does not sufficiently support
    high quality aquatic habitat, ANR’s requirement of an 18-inch drawdown will be imposed.
    Additionally, because neither MWL nor ANR’s recommendations support the existing use of
    whitewater boating, the final operational conditions need to include three scheduled whitewater
    boating releases to comply with the VWQS.
    Anti-Degradation Policy
    Under the Anti-Degradation Policy, “[e]xisting uses of waters and the level of water
    quality necessary to protect those existing uses shall be maintained and protected regardless of
    the water’s classification.” VWQS § 1-03(B)(1). Existing uses in the Lamoille Basin are identified
    as swimming, recreational boating, recreational fishing, and use as a public water supply. 2016
    Lamoille Basin Plan, p. 134. The Green River Facility is not used as a public water supply. We
    therefore focus our analysis on recreational uses.36
    Green River
    We begin our discussion with the Green River. Pursuant to our March 23, 2018 decision,
    the whitewater boating uses at issue in this appeal—boating on naturally occurring high flows
    and scheduled releases (together, the whitewater uses)—are existing uses at the Green River. In
    re Morrisville Hydroelectric Project Water Quality Certification, No. 103-9-16 Vtec, slip op. at 4-6
    (Vt. Super. Ct. Envtl. Div. Mar. 23, 2018) (Walsh, J.). In considering whether either ANR or MWL’s
    36
    Recreational uses are also protected as designated uses. See VWQS § 3-04(A)(5)-(6) (naming swimming,
    other primary contact recreational, boating, fishing, and other recreational uses as designated uses).
    55
    proposed conditions sufficiently support the existing use of whitewater boating, we conclude
    that neither set of conditions sufficiently support the use.
    In post-trial briefs, ANR submitted the theory that, even though whitewater boating is an
    existing use, the use does not need to be protected because whitewater boating does not require
    a higher level of water quality than the classification of the waterbody requires. ANR asserts that
    existing uses requiring water quality less stringent than designated uses are presumed to be fully
    supported when designated uses are supported. ANR asserts that whitewater boating requires
    less stringent water quality than the designated uses, and therefore, is supported.
    The Court gives “substantial deference to an agency’s interpretation of its own
    regulations,” here, the VWQS. ANR Permits, 
    2014 VT 50
    , ¶ 15, 
    196 Vt. 467
     (citing Peel Gallery,
    
    149 Vt. at 351
    ). “Absent a clear and convincing showing to the contrary, decisions made within
    the expertise of such agencies are presumed correct, valid and reasonable.” Johnston, 
    145 Vt. at 322
    .   Parties challenging ANR’s interpretation “bear the burden of showing that ANR’s
    interpretation is wholly irrational and unreasonable in relation to its intended purpose.” ANR
    Permits, 
    2014 VT 50
    , ¶ 17 (citations omitted); see also Plum Creek Me. Timberlands, LLC, 
    2016 VT 103
    , ¶ 28; In re Costco Stormwater Discharge Permit, 
    2016 VT 86
    , ¶ 5.
    Essentially, ANR asserts that only existing uses requiring more stringent water quality
    than designated uses are entitled to protection. This reading results in existing uses going
    unsupported and the Anti-Degradation Policy being rendered unnecessary.                 The Anti-
    Degradation Policy is intended to provide for meaningful protection of existing uses. VWQS § 1-
    03(B)(1). As a practical matter, AW/VPC provided credible evidence that the conditions imposed
    in the 2016 water quality certification would likely provide no actual whitewater boating
    opportunities. Therefore, as discussed below, while ANR’s conditions may support certain
    designated uses, in reality they would not support the existing whitewater boating use. ANR’s
    interpretation would therefore result in an irrational and unreasonable interpretation of the Anti-
    Degradation Policy. We do not defer to this interpretation.
    The Green River is narrow, shallow, and very rocky. Therefore, the only potential boating
    uses that could be supported on the river are the whitewater uses. The minimum flow required
    56
    to support these uses is between 128 and 140 cfs. A flow of 222 cfs provides the best flow level
    for a standard run and a flow of 280 cfs provides the best level for a highly challenging run.
    Presently, whitewater uses occur when naturally occurring high flows allow and during
    scheduled releases, usually scheduled through agreement between AW/VPC and MWL.
    Recently, except for 2013, these scheduled releases occurred 2 to 3 times a year. Both the MWL
    and ANR proposals will limit whitewater boating opportunities in a way that does not support
    the use.
    Under the MWL proposal, there is no requirement to conduct scheduled releases at any
    time of year. In the spring, after the refill period, MWL’s proposal sets a maximum generation
    flow of 60 cfs, or inflow, if greater, after the reservoir is refilled. Because 60 cfs is not a boatable
    flow, opportunities for whitewater boating would be limited to natural high flow events. At all
    other times of the year, the minimum downstream flow is not viable for boating, and whitewater
    boating would be similarly limited.        In the winter, however, MWL proposes a maximum
    generation flow of 160 cfs. This flow would support whitewater boating when MWL chooses to
    generate.
    ANR’s conditions as set forth in the 2016 water quality certification will also impact the
    whitewater uses. During the winter months, MWL would be permitted to operate in store and
    release mode, but the certification places a maximum generation flow at 110 cfs, unless inflow
    exceeds that amount. 110 cfs is not a boatable flow so opportunities for whitewater boating
    would be limited to naturally occurring flows higher than 110 cfs. MWL, however, is not required
    to pass these naturally occurring high flows downstream and their passage would be dependent
    upon whether MWL is generating and the reservoir drawdown at that time. Whitewater boaters
    could not utilize the store and release operation for scheduled releases.
    In the spring, the water quality certification does not permit the passing of naturally
    occurring high flows during the refilling period. In the summer and fall months, naturally
    occurring high flows must be passed down the Green River from the Green River Reservoir,
    however, the opportunities for boating may be limited because natural high flows may also be
    limited at this time. Further, during these periods, minimum downstream flows are not boatable.
    57
    Under both flow conditions, scheduled releases would not be permitted and MWL would
    not be able to place these releases at a time during which whitewater boaters could take
    advantage of the use by time shifting.
    Time shifting would occur, for example, if a naturally occurring high flow were to take
    place overnight or on a weekday during which most whitewater boaters could not participate in
    the use. If time shifting were permitted, MWL could hold that natural high flow in the reservoir
    for a few hours or days and then release it at a time when boaters could take advantage of the
    opportunity, for example, during daylight hours on the weekends. If time shifting were not
    permitted, but naturally occurring high flows were to be passed, a boatable flow could occur but,
    because of its inconvenient and unsafe time, few or no boaters would be able to take advantage
    of it.
    Central to the issue of supporting the existing use of whitewater boating is the timing of
    when high flow events occur. Under both ANR’s conditions and MWL’s proposal, naturally
    occurring high flow events that are boatable will be passed downstream at various times
    throughout the year. Just because a flow is boatable, however, does not make that flow a
    whitewater boating opportunity. Only scheduled releases allow for boatable flows to occur for
    a sufficient duration when boaters can take advantage of them.
    We conclude that merely passing naturally occurring high flow is not sufficient to support
    the existing whitewater uses at the Green River. To adequately support the use, scheduled
    releases must occur at a time during which boaters can take advantage of the flows, such as
    weekend daylight hours. Neither the conditions imposed by ANR through the 2016 water quality
    certification nor the MWL proposal require scheduled releases to support whitewater boating on
    the Green River. Therefore, both sets of conditions as presented fail to support this existing
    use.37
    37
    The Court notes that the primary focus of the Anti-Degradation Policy at the Green River Facility was
    whitewater boating. To the extent that recreational fishing and swimming exist at the Green River, both ANR’s
    conditions imposed in the 2016 water quality certification and MWL’s proposed conditions would support both uses
    on the Green River. With respect to recreational fishing, for the reasons set forth below, both proposals will support
    the designated use of aquatic biota, wildlife, and habitat. Further, both proposals support year-round adequate
    flows in the river, such that swimming would be supported, to the extent it exists.
    58
    Evidence before the Court shows that two to three scheduled releases have occurred
    annually and, therefore, three scheduled releases of boatable flows must occur annually, during
    times at which boaters may take advantage of the flows.38
    Green River Reservoir
    The Green River Reservoir is a popular recreation destination and is in the Green River
    Reservoir State Park. Currently, the reservoir supports the uses of recreational non-motorized
    boating, fishing, swimming, and camping.
    MWL’s proposed drawdown of six feet would be in keeping with the current drawdown
    conditions, which support these uses as they currently exist.                          Alternatively, the 1.5-foot
    drawdown condition imposed by the 2016 water quality certification would result in smaller
    fluctuations in water level at the reservoir and, for the reasons set forth below, provide high
    quality aquatic habitat therein. Therefore, we conclude that both proposals would support the
    existing recreational uses within the Green River Reservoir.
    Water Quality Criteria
    Waters must comply with the general water quality criteria as well as the applicable
    criteria for their class. VWQS § 3-01; VWQS § 3-04(B) (setting water quality criteria for Class B
    waters). As noted above, this appeal focuses on the DO and temperature criteria.
    Gomez & Sullivan, in coordination with ANR, conducted a water quality monitoring study
    at the Project. The study’s goals and general approach are set forth above in Section IV.a “Water
    Quality Criteria for Class B Waters.”
    At the Green River Facility, six sampling locations were identified: three within the Green
    River Reservoir, at the reservoir’s linear center, the thalweg station, and the penstock tap; and
    three at various locations within the Green River, downstream from the dam at the tailrace, near
    Garfield Road, and near the river’s confluence with the Lamoille River. The locations within the
    reservoir were sampled periodically from May to October of the study year, whereas the
    locations downstream from the dam were sampled both periodically, also from May to October,
    38
    AW/VPC asserted at trial that seven annual releases would be supported by the naturally occurring flows
    in the Green River and would be utilized by the boating community. In its post-trial brief, it asserted that five releases
    would support the use. We have no evidence that scheduled releases have occurred at either frequency and we
    conclude that both requests exceed that which is necessary to support the use as it currently exists.
    59
    and continuously. Continuous monitoring for temperature occurred from April 26, 2012 to
    November 19, 2012 and continuous monitoring for DO occurred for nine days in September 2012.
    Dissolved Oxygen
    At the Green River Facility, DO must be not less than 6 milligrams per liter (mg/l), with
    70% saturation at all times. VWQS § 3-04(B)(2)(a).
    The parties agree that existing conditions do not conform to the VWQS for DO. This is
    largely due to the nature of the store and release operation of the dam. When drawing water
    from the reservoir, the water is not pulled from the top of the reservoir, but from deeper within
    the impoundment. Because of stratification, this is typically where low DO water accumulates.
    When DO is measured at the facility’s tailrace, DO does not comply with the VWQS.
    Further downstream, however, after the river naturally aerates the water, the waters come into
    compliance. MWL asserts that modifications to the facility’s equipment will bring the river into
    compliance. ANR expert Mr. Crocker testified that he has no concerns regarding MWL’s proposal
    regarding the DO requirements of the VWQS. Therefore, we conclude MWL’s proposal will
    comply with the DO requirements of the VWQS.
    Temperature
    The total allowable increase above the ambient temperature is one-degree Fahrenheit at
    the Green River Facility. VWQS § 3-01(B)(1)(b). The facility is presently meeting the temperature
    standards and ANR does not raise concerns regarding temperature with respect to MWL’s
    proposal.
    Designated Uses
    Designated uses in Class B waters include: aquatic biota, wildlife, and aquatic habitat;
    aesthetics; public water supply; irrigation of crops and other agricultural uses; swimming and
    other primary contact recreational uses; and boating, fishing and other recreational uses. VWQS
    § 3-04(A)(1)-(6). Unlike the Morrisville and Cadys Falls Facilities, the designated use of aesthetics
    is not at issue at the Green River Facility. Further, because the waters at the Green River Facility
    are not used as a public water supply or for irrigation or agriculture, and because recreational
    uses are discussed above, we analyze only the designated use of aquatic biota, wildlife, and
    habitat here.
    60
    High quality aquatic habitat must be available to support aquatic biota, wildlife, and
    aquatic habitat. VWQS § 3-04(A)(1). For the reasons set forth below, we find MWL’s proposed
    flow regime will support high quality aquatic habitat within the Green River. ANR’s flow regime
    imposes excessive flow requirements that go beyond the VWQS. However, MWL’s proposed
    winter drawdown will not provide high quality aquatic habitat, while ANR’s prescribed drawdown
    does comport with the VWQS.
    Green River
    The Green River is approximately 4.3 miles long and flows from the dam to its confluence
    with the Lamoille River. Approximately 1.5 miles downstream from the dam is a culvert at
    Garfield Road. This culvert prevents fish from accessing the section of the river upstream from
    the culvert. Fish could, however, move downstream through the culvert. There is a self-
    sustaining population of brook trout above the culvert as well as self-sustaining populations of
    both brook and brown trout below the culvert. In addition, there is a 10 to 15 foot-high falls
    located 3.2 miles downstream from the dam. This is potentially a year-round barrier to fish
    moving upstream.
    Throughout the river there are various features such as riffles, pools, including step pools,
    runs, and falls. The channel includes bedrock, fine gravel, course gravel, cobble, boulder
    substrate, with in-stream vegetation, woody debris, and overhanging vegetation. The banks are
    vegetated and mossy. These conditions provide in-stream cover for fish.
    Like at the Morrisville and Cadys Falls Facilities, Gomez & Sullivan performed a flow study
    at the Green River in 2012. This study developed habitat and flow relationships for the target
    species in the Green River at different life stages, including spawning and incubation, late fry,
    juvenile, and adult brook, brown, and rainbow trout, early fries of all trout, spawning and
    incubation for longnose suckers, and macroinvertebrates. The study utilized IFIM to assess the
    Green River, specifically a transect-based PHABSIM approach. This methodology allows transect
    information, such as depth, velocity, and substrate, to be combined with aquatic habitat
    suitability index curves to determine the weighted usable area of habitat as compared to flow at
    the selected transects.
    61
    Nine transects were identified in the Green River, five of which were specifically
    designated to address spawning habitat. These transects generally were spread throughout the
    river to study different types of habitat, including riffle, pool, and run, as well as substrate.
    Data collection occurred at flows of 10 cfs and 75 cfs. An attempt was made to collect
    data at 160 cfs, but the velocities resulted in the stream not being wadeable.
    MWL experts conducted a time series analysis to complete their understanding of the
    Gomez & Sullivan PHABSIM modeling, as it did at the Morrisville and Cadys Falls Facilities. The
    time series was based on historical flow information from the Garfield gauge.
    In October 2017, Ms. Nealon conducted fish monitoring at the Green River with a team
    from Bear Creek Environmental and Normandeau Associates.                       This monitoring sought to
    determine if current conditions comply with the aquatic biota, wildlife, and habitat use. Four
    monitoring stations were selected at river miles 3.5, 3.2, 2.9, and 0.1.                     Two rounds of
    electrofishing were conducted at each station, at a minimum, and the data was analyzed using
    the Indices of Biotic Integrity (IBI). The Vermont Mixed Water IBI and the Coldwater IBI were
    used. Stations located at river mile 3.2 received an assessment of very good, and river miles 2.9
    and 0.1 received assessments of excellent under the IBI. 39
    Under existing conditions, an overall weighted average of 76% of habitat, relative to the
    amount of habitat under a natural flow regime, is currently provided. Under MWL’s proposed
    flow regime, an average of 95% of habitat will be provided as compared to a natural flow regime.
    Under the conditions imposed by the 2016 water quality certification, 111% of habitat will be
    available relative to a natural flow regime. An average of 76% of habitat under a natural flow
    regime, for the same reasons as discussed above in Section IV.a “Designated Uses”, supports high
    quality aquatic habitat in the reach. An increase, such as under the MWL proposed flow regime,
    would provide further assurances that high quality habitat will be provided.
    ANR has raised concerns regarding the higher flows proposed by MWL and their effect on
    fish populations. Specifically, ANR addressed the issue of peak flows during spawning.40 It is
    ANR’s opinion that peaking generally negatively affects fish populations, especially with respect
    39
    River mile 3.5 was not evaluated using the IBI because it had a soft bottom.
    40
    ANR again raises concerns with MWL using averages in their habitat analysis. For the same reasons as
    above, we do not share these concerns.
    62
    to immobile or low mobility life stages. ANR relied upon the PHABSIM Gomez & Sullivan flow
    study in reaching its conclusions regarding the flows in the Green River, which indicate that
    consistent and lower flows support high quality aquatic habitat.
    Current conditions in the Green River, under a flow regime that permits maximum
    generation flows of 283 cfs and 160 cfs at various times of year, support abundant fish
    populations. Currently, there is a self-sustaining brook trout population above the Garfield Road
    culvert, self-sustaining populations of brook and brown trout below the culvert, and the river
    supports spawning habitat.
    Ms. Nealon’s expert report contains the results of her fish population study showing very
    good to excellent fish populations in the river. Mr. Wentworth opined that the Court should not
    give this very much weight. His opinion seems to be based on the fact that we presently lack
    data as to what has been going on over longer time scales with respect to fish in the Green River,
    such as factors that may be controlling the population, like physical habitat. Ms. Nealon’s study,
    he opined, is a snapshot of the present population which lacks the sort of multi-annual and
    seasonal data which would provide a full understanding of the population. Importantly, Mr.
    Wentworth did not look through the study or its results thoroughly and only “flipped through.”
    Instead, ANR and Mr. Wentworth rely upon the PHABSIM modeling to support the 2016
    water quality certification flow regime. We note that at various flows the modeling assigns a
    zero-habitat value. We know, however, that current flows support fish populations in the Green
    River in reality. While we value the information that modelling can provide, we cannot neglect
    the actual conditions at a given location, especially when the two contradict one another.
    The fish population results are indeed a snapshot of the population at a given time.
    However, high quality aquatic habitat is currently being provided within the reach and, under the
    current regime, in which generation is permitted at very high flows, this snapshot shows that fish
    populations are abundant in the habitat.
    We conclude that MWL’s proposed flow regime, increasing habitat availability from 76%
    to 95% as compared to a natural flow regime in the Green River, will provide high quality aquatic
    habitat and therefore satisfies the aquatic biota, wildlife, and habitat designated use. ANR’s flow
    63
    regime provides 111% habitat of a natural flow regime which is in excess of what the VWQS
    require.41
    Green River Reservoir
    The Green River Reservoir has a typical maximum water surface area of roughly 653 acres.
    The normal maximum water elevation is 1220 feet with a depth of 93 feet. Currently, MWL is
    permitted to draw down the reservoir in the winter (from December 1 to April 30) a maximum
    of ten feet. In practice, MWL has on average drawn the reservoir down 3.7 feet. The maximum
    winter drawdown occurred in the winter of 2009-2010 and was 5.9 feet.
    ANR performed a littoral habitat assessment of the Green River Reservoir in 2014. The
    assessment sampled 17 sites at the reservoir and compared the Green River Reservoir’s littoral
    habitat to those of reference waterbodies.                 The reference waterbodies were eight large
    mesotrophic lakes sampled by ANR in 2007 and 2008, at which 54 sites were sampled. These
    samples provided conditions of waterbody types like that of the Green River Reservoir. Sites
    were assessed for substrate composition, aquatic plant cover, woody debris, embeddedness,
    odonate exuviae (dragonfly exoskeletons), and riparian habitat characteristics.
    The assessment concluded that the reservoir’s littoral zone had many areas that were
    highly suitable for aquatic macrophyte growth but that currently lacked macrophytes and, as
    compared to these eight reference waterbodies, the reservoir had less aquatic plant cover and
    odonate exuviae. The assessment concluded that these impacts are consistent with those
    associated with water level fluctuations, such as winter drawdowns.
    MWL expert Kurt Jirka conducted an evaluation of the impacts of the current drawdown
    and those the 2016 water quality certification would have in the Green River Reservoir. Mr Jirka
    conducted a site visit on July 20, 2017 and made qualitative observations of the reservoir’s
    physical and biological attributes.
    MWL asserts that a six-foot maximum winter drawdown will provide high quality aquatic
    habitat. This is based on Mr. Jirka’s observational assessment of the reservoir’s current physical
    41
    VNRC and TU ask: “[w]hether hydropeaking and modified run-of-river flows in the Green River allowed
    in the water quality certificate issued for the Project do not comply with the VWQS, including the provisions in the
    standards that require support and protection of aquatic habitat and biota.” In reaching the conclusion that existing
    conditions, which include peaking, support high quality aquatic habitat, we answer this question in the negative.
    64
    and biological attributes under the current drawdown regime. No quantitative assessment of
    plant presence, substrate composition, fish populations, macroinvertebrate richness, or other
    wildlife presence was conducted in relation with this assessment. This cursory, observational
    assessment of the Green River Reservoir does not support the conclusion that the current
    drawdown regime supports high quality aquatic habitat in the reach.
    Further, ANR has provided an alternative assessment of the littoral zone. ANR’s littoral
    habitat assessment concluded that the Green River Reservoir’s littoral zone was less developed
    as compared with other reference waterbodies, despite having adequate substrate for aquatic
    biota. The assessment concluded this was a result of historical drawdown regimes at the
    reservoir.
    Because MWL has failed to demonstrate that its proposed winter drawdown regime
    supports high quality aquatic habitat, we conclude that a maximum winter drawdown of six feet
    does not support high quality aquatic habitat within the Green River Reservoir. Further, MWL
    has not provided persuasive justification supporting the assertion that ANR’s condition of a 1.5-
    foot drawdown does not comply with the VWQS. Therefore, we decline to adopt MWL’s proposal
    and the 2016 water quality certification’s condition on winter drawdown is affirmed.
    f. The Green River Facility as an existing use pursuant to VWQS § 1-03(B)(1)(d)
    For the same reasons as set out with respect to the Morrisville Facility, we conclude that the
    hydroelectric generation at the Green River Facility is an existing use pursuant to VWQS § 1-
    03(B)(1)(d).
    We note, however, that our above analysis regarding MWL’s proposed conditions at the
    facility does not depend on the facility’s existing use status. Therefore, MWL’s proposed flow
    conditions at the Green River Facility complies with the VWQS, even without the consideration
    of the facility’s existing use status. Further, we note that MWL does not argue that it cannot
    operate or operate practically without the six-foot drawdown it proposed. Therefore, there is
    no need to balance the existing uses and our above analysis of the proposal is not affected by our
    conclusion that the Green River Facility is an existing use.
    65
    V.      Phase-In
    The Hydrology Policy states that conditions imposed should “preserve, to the extent
    practicable, the natural flow regime of waters.” VWQS § 1-02(E)(1). Consideration must be given
    to existing operation of “dams, diversions, and other control structures.” Id. Here, all bypass
    reaches and downstream flows are affected by the existence of the MWL facilities.
    The Hydrology Criteria are those criteria used to implement the Hydrology Policy. For
    Class B waters, “[a]ny change from the natural flow regime shall provide for maintenance of flow
    characteristics that ensure the full support of uses and comply with the applicable water quality
    criteria.” VWQS § 3-01(C)(1)(c).
    MWL argues that the water quality certification does not comply with the Hydrology
    Policy because it fails to include a phase-in period during which it could implement the necessary
    equipment modifications and construction. MWL argues that phase-in is required based on its
    interpretation of the term “practicable.” Because there is no definition of “practicable” in the
    VWQS, MWL turned to the Vermont Wetland Rules, which defines practicable or practicability as
    “available and capable of being done after taking into consideration logistics, existing technology
    and cost in light of [the] overall project purpose.” Vt. Code of Regulations 12004056, § 2.28.
    MWL asserts it is entitled to a phase-in period because of the necessary modifications and
    construction, under either its own proposal or ANR’s certification.
    ANR asserts that a phase-in period is not authorized under the Hydrology Policy. ANR
    interprets “practicable” as referring to the preservation of the natural flow regime to the extent
    practicable, not the preservation of hydroelectric facilities to the extent practicable. ANR asserts
    that permitting a phase-in within the water quality certification would contravene the CWA and
    cites to an unreported Florida case interpreting the CWA in the context of a different permitting
    regime. See Miccosukee Tribe of Indians v. United States, 
    1998 WL 1805539
    , at * 16 (S.D. Fla.
    1998). Further, ANR contends that there is no authority within the VWQS to permit a phase-in
    period and, therefore, one cannot be included. See In re Star-Kist Caribe, Inc., 
    1990 WL 324290
    ,
    at *2 (EPA, Apr. 16, 1990).
    We owe deference to ANR’s interpretation of policy or terms when: “(1) that agency is
    statutorily authorized to provide such guidance; (2) complex methodologies are applied; or (3)
    66
    such decisions are within the agency’s ‘area of expertise.’” Korrow Real Estate, LLC, 
    2018 VT 39
    ,
    ¶ 20 (citation omitted). As stated above, the Court gives deference to ANR’s interpretation of
    the VWQS, however, “the deference owed to agency determinations is not absolute.” 
    Id., ¶ 21
    (citation omitted). “An agency’s authority to define terms within its statutory purview will be
    given deference unless that authority is applied ‘arbitrarily and capriciously’ such that it ‘give[s]
    rise to a violation of due process.’” 
    Id.
     (citing In re Woodford Packers, Inc., 
    2003 VT 60
    , ¶ 17, 
    175 Vt. 579
    ).
    In Vermont, the Secretary of ANR has the authority to review, establish, and revise the
    water quality standards. See 
    40 C.F.R. § 131.4
    (a) (giving states the authority to review, establish,
    and revise water quality standards); 10 V.S.A. § 1252(e) (requiring the Secretary of ANR to adopt
    water quality standards). As such, it is within ANR’s discretion to define the terms within the
    VWQS. However, practicable is undefined in the VWQS.
    It is uncontested that ANR issued a water quality certification to Green Mountain Power
    in 2016 which contained phase-in measures in the form of interim and immediate compliance
    deadlines tied to construction. Here, however, ANR asserts that a phase-in schedule is not
    permissible under the Hydrology Policy and, further, is not authorized by the VWQS. It is unclear
    why a phase-in schedule would be permissible to another permittee but impermissible here.
    Because ANR’s interpretation has been applied arbitrarily and capriciously, we decline to afford
    it deference or adopt it here. See In re Champlain Coll. Maple St. Dormitory, 
    2009 VT 55
    , ¶ 10,
    
    186 Vt. 313
     overruled on other grounds; In re Confluence Behavioral Health, LLC, 
    2017 Vt. 112
    (2017) (declining to adopt a zoning interpretation that has not been consistently applied).
    We further note that MWL’s interpretation appears to be implicitly supported by In re
    Clyde River Hydroelectric Project, 
    179 Vt. 606
    , 610 (2006). In that case, appellants asserted that
    the Water Resources Board violated the VWQS by applying different criteria to the relevant
    bypass reach and the rest of the river. 
    Id.
     In rejecting that argument, the Vermont Supreme
    Court stated that the Hydrology Policy is specific to existing dams, and cites the language at issue
    here, emphasizing the phrase “to the extent practicable.” 
    Id.
     The Supreme Court’s discussion
    supports interpreting the phrase “to the extent practicable” in a way that refers to existing dams,
    as opposed to the preservation of the natural flow regime.
    67
    For these reasons, we conclude that a phase-in period is permissible under the VWQS.
    MWL asserts that it will require ten years to be in compliance with any flow regime
    imposed on it. During this time, MWL wishes to operate under its current flow regime.
    The purpose of the VWQS is to “restore and maintain the chemical, physical, and
    biological integrity of the Nation’s waters.” VWQS § 1-02. This is the same objective as the CWA.
    
    33 U.S.C. § 1251
     et seq. FERC licenses are valid for 30 to 50 years. Excessive delay would diminish
    the objectives of the VWQS and CWA.
    MWL contends that it would take three to five years to implement a new flow regime at
    the Morrisville and Green River Facilities and four to ten years to implement a new flow regime
    at the Cadys Falls Facility. VNRC asserts that the upgrades to the Green River Facility could be
    accomplished in two to three years, in three years at the Cadys Falls Facility, and in one year at
    the Morrisville Facility. Further, MWL concedes that current equipment at the Morrisville Facility
    could potentially be reprogrammed to pass a flow of 70 cfs. Additionally, MWL concedes that
    existing equipment would allow for the passage of a flow of 100 cfs at the Cadys Falls Facility.
    However, additional equipment must be installed to fully comply and to operate each of the
    facilities remotely.
    MWL asserts that it cannot undertake these projects concurrently due to management
    capabilities. MWL provided no specific expectations for equipment delivery or installation and
    has done no assessment of these expectations. None of the required equipment would need to
    be specially designed for the Project.
    We first note that many of the concerns raised by MWL address economic factors outside
    of the scope of this Court’s review, specifically with respect to the sequencing of construction.
    Morrisville Hydroelectric, No. 103-9-16 Vtec, slip op. at 17 (Jun. 13, 2017). Further, the general
    assertions provided by MWL do not support the imposition of a separate phase-in period for each
    facility, during which MWL would be in non-compliance with the relevant laws for one-third to
    one-fifth of the license period.
    We conclude that a total phase-in period of four years for all three facilities is warranted.
    At the termination of this period, MWL must comply with all aspects of the water quality
    certification at all three facilities.
    68
    Conclusion and Order
    For the foregoing reasons, we conclude that MWL’s proposed flow regimes at the
    Morrisville, Cadys Falls, and Green River Facilities comply with the VWQS. We conclude,
    however, that a six-foot drawdown at the Green River Reservoir does not support the designated
    use of high quality aquatic habitat in the reservoir. Therefore, we conclude that ANR’s condition
    limiting the winter drawdown to 18 inches is required to provide high quality aquatic habitat.
    Further, we conclude that the existing use of whitewater boating at the Green River must be fully
    supported by annually providing three scheduled whitewater boating releases, lasting for a
    duration of at least six hours each. Lastly, a total phase-in period of four years for all three
    facilities is warranted. At the termination of this period, MWL must comply with all aspects of
    the water quality certification at all three facilities.
    This concludes the matter before the Court. A Judgment Order accompanies this merits
    decision.
    Electronically signed on September 18, 2018 at 03:28 PM pursuant to V.R.E.F. 7(d).
    _________________________________________
    Thomas G. Walsh, Judge
    Superior Court, Environmental Division
    69
    

Document Info

Docket Number: 103-9-16 Vtec

Filed Date: 9/18/2018

Precedential Status: Precedential

Modified Date: 7/31/2024