DATE FILED: May 4, 2020 4:16 PM
FILING ID: 9496BF76F4C96
CASE NUMBER: 2014CW3043

EXHIBIT A-3 TO RIO BLANCO WCD EXPERT DISCLOSURES

 May 1, 2020

1. Introduction
The Rio Blanco Water Conservancy District (RBWCD) has filed an application for surface water
right and storage water right in Colorado Division 6 water court Case No. 14CW3043. The
application includes the proposed use of those rights for maintenance and recovery of federally
listed threatened and endangered species. This report discusses the proposed Wolf Creek
Reservoir, provides an analysis of the hydrology, physical habitat, biological conditions, and
flow recommendations for the White River in Colorado and Utah. I have prepared this report
for the Rio Blanco Water Conservancy District to summarize my analyses and opinions on the
need for water storage in Wolf Creek Reservoir and subsequent release to benefit the
endangered fish species in the White River in Colorado and Utah.

1.1. LIST OF DOCUMENTS AND INFORMATION RELIED UPON
The information in this report is based on the following data sources:
1. White River Storage Feasibility Study, Phase 1 Report. W.W. Wheeler & Associates,
Inc. Englewood, CO 80110, prepared for the Rio Blanco Water Conservancy District,
May 2014.
2. White River Storage Feasibility Study, Final Report. W.W. Wheeler & Associates, Inc.,
Englewood, CO. Prepared for the Rio Blanco Water Conservancy District. March 4,
2015.
3. Application for Surface and Storage Water Right, Case No. 14CW3043.
4. Engineers’ Reply in Support of Motion to Intervene; Concerning the Application for
Water Rights of: The Rio Blanco Water Conservancy District, Case No. 14CW3043.
November 27, 2019.
5. Letter from Andrew Nicewicz Colorado Assistant Attorney General to Alan E. Curtis,
White and Jankowski, LLC. November 22, 2019. Regarding Case No. 14CW3043.
6. Draft Review of Fish Studies with Interim Flow Recommendations for Endangered
Fishes of the White River, Colorado and Utah. D.M. Anderson, T.W. Econopouly, J.
Mohrman, T. Jones, M.J. Breen and T. Chart. November 5. 2019.
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7. White River Base Flow Study for Endangered Fishes, Colorado and Utah, 1995-1996.
Final Report. Project 65. Prepared for Upper Colorado River Basin Recovery
Implementation Program, G.B. Haines, D. Irving, and T. Modde, US Fish and Wildlife
Service, Vernal Utah, February 2004.
8. Flow Recommendations for the White River, Utah-Colorado, Draft Report. Prepared
for Upper Colorado River Basin Recovery Implementation Program. Geomorphic
analysis in support of a channel maintenance flow recommendation for the White
River near Watson, Utah. J.D. Schmidt and K.L. Orchard, Department of Earth
Sciences, Utah State University. And. Base Flow Recommendations for Endangered
Fishes in the White River, Colorado and Utah, 1995-1996. D. Irving, B. Haines, and T.
Modde. U.S. Fish and Wildlife Service, Vernal Utah. August 2002.
9. The White River and Endangered Fish Recovery: A Hydrological, Physical and
Biological Synopsis. Publication Number 00-37, Utah Division of Wildlife Resources,
Salt Lake City, Utah. Final Report Sept. 1998, Updated and Edited Sept. 2000. L.D.
Lentsch, B.G. Hoskins and L.M. Lubonudrow (1998). M.E. Anderson and A. Paschal,
(2000).
10. Completion Report, Yampa-White Physical Habitat Study, C.G. Prewitt, B.A. Caldwell,
W. Miller; in Colorado River Fishery Project, Final Report Yampa River, W.H. Miller,
D. Archer, H.M. Tyus and R.M. McNatt, U.S. Fish and Wildlife Service, Salt Lake City,
Utah, April, 1982.
11. Upper Colorado River Endangered Fish Recovery Program. General information
pages. https://www.coloradoriverrecovery.org
12. Stream Flow Needs of Rare and Endangered Fishes, Yampa River, Colorado. H.M.
Tyus and C.A. Karp. U.S. Fish and Wildlife Service, Vernal Utah. April 1, 1988.
13. Flow Recommendations for Endangered Fishes in the Yampa River. T. Modde and G.
Smith, U.S. Fish and Wildlife Service. November 1995.
14. Management Plan for Endangered Fishes in the Yampa River Basin, Environmental
Assessment. G. Roehm, U.S. Fish and Wildlife Service, Denver, Colorado September,
2004.
15. Minimum Flow Recommendation for Passage of Colorado Squawfish and Razorback
Sucker in the 2.3-Mile Reach of the Lower Gunnison River: Redlands Diversion Dam
to the Colorado River Confluence, B.D. Burdick U.S. Fish and Wildlife Service, Grand
Junction, Colorado. January 1997.

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16. Movement, Migration and Habitat Preference of Radio-telemetered Colorado
Squawfish; Green, White and Yampa Rivers, Colorado and Utah. U.S. Fish and
Wildlife Service, Colorado River Fishery Project, Salt Lake City, Utah, January 20,
1983.
17. Riverine Fish Flow Investigations, Federal Aid Project F-289-R6, R. Anderson and G.
Stewart, Colorado Division of Wildlife, Fort Collins, Colorado, June 2003.
18. Determination of habitat availability, habitat use, and flow needs of endangered
fishes in the Yampa River between August and October. T. Modde, W.J. Miller, and
R. Anderson. Recovery Implementation Program Project #CAP-9, April, 1999.
19. Chapter 4: Habitat Use, W. Miller and T. Modde, in Determination of habitat
availability, habitat use, and flow needs of endangered fishes in the Yampa River
between August and October. T. Modde, W.J. Miller, and R. Anderson. Recovery
Implementation Program Project #CAP-9, April, 1999.
20. An Evaluation of the Role of Tributary Streams for Recovery of Endangered Fishes in
the Upper Colorado River Basin, with Recommendations for Future Recovery
Actions. Project Number 101, Upper Colorado Endangered Fish Recovery Program,
H.M. Tyus and J.F. Saunders, Center for Limnology, University of Colorado, Boulder,
Colorado. March 29, 2001.
21. Home-Range Fidelity and Use of Historic Habitat by Adult Colorado Pikeminnow
(Ptychocheilus Lucius) in the White River, Colorado and Utah. D. Irving and T.
Modde. Western North American Naturalist 60(1): 16-25, 2000.
22. Colorado Squawfish Habitat Use and Movement during Summer Low Flow in the
Yampa River Upstream of Cross Mountain Canyon. Prepared for Colorado River
Water Conservation District, Glenwood Springs, Colorado. W.J. Miller and D.E. Rees,
Miller Ecological Consultants, Inc. Fort Collins, Colorado. December 17, 1997.
23. Colorado Squawfish Winter Habitat Study, Yampa River, Colorado, 1986-1988. E.J.
Wick and J.A. Hawkins, Larval Fish Laboratory, Colorado State University, Fort
Collins, Colorado. February, 1989.
24. Fishes and Macroinvertebrates of the White and Yampa Rivers, Colorado. Final
Report on a Baseline Survey Conducted for the Bureau of Land Management. C.A.
Carlson, C.G. Prewitt, D.E. Snyder, E.J. Wick, E.L. Ames, and W.D. Fronk. Colorado
State University, Fort Collins, Colorado. February, 1979.
25. Distribution of Fishes in the White River, Utah. S.H. Lanigan and C.R. Berry, Jr. The
Southwestern Naturalist 26(4):389-393, November 20, 1981.

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26. Colorado Pikeminnow Habitat Use in the San Juan River, New Mexico and Utah. W.J.
Miller and J.A. Ptacek, Miller Ecological Consultants, Fort Collins, Colorado, January
31, 2000.
27. Flow Recommendations to Benefit Endangered Fishes in the Colorado and Gunnison
Rivers, C. W. McAda. U.S. Fish and Wildlife Service, Grand Junction, Colorado, 2003.
28. Streamflow Needs of Rare and Endangered Fishes: Yampa River Interim Flow
Recommendations, Final Report. U.S. Fish and Wildlife Service, Region 6, Denver,
Colorado. March 5, 1990.
29. Procedures for Releasing and Administering Water from Elkhead Reservoir to
Augment Yampa River Flows for Endangered Fish. J. Mohrman and D. Anderson.
Upper Colorado River Endangered Fish Recovery Program. October 3, 2017.
30. Final Programmatic Biological Opinion for Bureau of Reclamation’s Operations and
Depletions, Other Depletions, and Funding and Implementation of Recovery
Program Actions in the Upper Colorado River above the Confluence with the
Gunnison River. U.S. Fish and Wildlife Service. Lakewood, Colorado. December
1999.
31. Exhibit A – Scope of Work, White River Management Plan. December 19, 2019.
32. Sources of Water for Endangered Fishes in the Colorado River. News Release,U.S.
Fish and Wildlife Service, Denver, Colorado. January 10, 2014.
33. Memorandum from Robert Muth to Erin Light providing the Rationale for
Management of Water Releases from the Elkhead Reservoir Endangered Fish Pool to
Augment August -October Base Flows in the Yampa River, Upper Colorado River
Endangered Fish Recovery Program, April 3, 2008.
34. Final Programmatic Biological Opinion on the Management Plan for Endangered
Fishes in the Yampa River Basin. Regional Director, Region 6, Fish and Wildlife
Service, Denver Colorado. January 10, 2005.
35. Dedication of Elkhead Dam & Reservoir Enlargement in Northwest Colorado. News
Release, Upper Colorado River Endangered Fish Recovery Program. Denver,
Colorado. July 2, 2007.
36. Microsoft Excel spreadsheet created by W.J. Miller to calculate stream flow volume
for each interim instream flow recommendation and wetted perimeter for riffles.

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37. Evaluation of Instream Flow Methods and Determination of Water Quantity Needs
for Stream in the State of Colorado, R.B Nehring, Colorado Division of Wildlife,
September 1979.
38. Expert Report for Case No. 14CW3043, Water Division 6, May 2020. W.W. Wheeler
and Associates, Inc.

1.2. Background on Instream Flow needs and Flow Recommendations for the federally
listed Colorado Pikeminnow (Ptychocheilus lucius) and Razorback Sucker (Xyrauchen
texanus) in the Upper Colorado River Basin.
The Upper Colorado River Endangered Fish Recovery Program (UCRRIP) was established in 1988
with the dual objectives of recovery of the endangered fishes and allow water development to
proceed in accordance with federal and state laws (Figure 1). The UCRRIP Partners include the
State of Colorado and Colorado Water Congress. The UCRRIP has set the objective of recovery
of the endangered fishes not just to maintain the status quo. The objective will be met when
the fishes are first downlisted to “threatened” and then delisted with removal from Endangered
Species Act protection (Figure 2).
One element of the UCRRIP is identification and protection of instream flows to restore river
and floodplain habitat to benefit endangered fishes (Figure 3). Studies to identify appropriate
instream flow needs in the Upper Basin have occurred in the mainstem Colorado, Green,
Gunnison, Yampa and White Rivers at various times since the early 1980s. The studies included
hydrologic data, geomorphology data, measurement of physical habitat in these rivers,
computer simulations of the relationship between habitat and various levels of flow (Prewitt et
al. 1982; Haines et al. 2004; Modde et al. 1999; Tyus and Karp 1988; Modde and Smith 1995;
Schmidt and Orchard 2002, Burdick 1997). The results of these studies have been used to set
appropriate instream flow regimes to benefit endangered fishes in the Upper Colorado River
Basin. These flow recommendations have been an integral part of the Programmatic Biological

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Opinions in the 15 Mile Reach (Colorado River upstream of the Gunnison River) and Yampa
River (McAda 1999, Roehm 2004).

1.3. Sources of water secured to benefit endangered fishes in the Colorado and Yampa
Rivers.
Reservoirs in the Colorado River and Yampa River currently provide a portion of the flow
volume specified in the flow recommendations for those rivers. Source of the water comes
from multiple reservoir locations and multiple entities. The flow recommendations for those
two rivers vary by season. The recommended flow regime specifies timing and volume to
benefit spawning, rearing and winter habitats. The Coordinated Reservoir Operations in the
Colorado River basin were established in 1995 and can provide additional water during peak
runoff to benefit spawning endangered fishes. In years with high snowpack and potential extra
water in the basin, the reservoir operators coordinate releases in spring to increase the peak
flow in the 15 Mile Reach and benefit the endangered fishes. This coordinated release of water
can provide a higher peak flow than the previous non-coordinated release during high
snowpack years. Additional water (10825 acre-feet) for summer and fall releases to benefit
endangered fishes was secured in agreements with water users and the Recovery Program in
2014. The 10825 water is released from Granby Reservoir and Ruedi Reservoir.
Water to benefit endangered fishes in the Yampa River is leased by the Recovery Program from
Elkhead Reservoir. The water was secured as part of the dam rehabilitation and enlargement of
the reservoir completed in 2007 (US Fish and Wildlife 2007). The release procedures are laid
out in a series of UCRRIP documents, which include Muth (2008) and Mohrman and Anderson
(2017). The releases are generally made to maintain late summer and early fall stream flows at
or above the recommended flows for that time of year.

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Figure 1. Excerpt from UCRRIP website showing the date of establishment and purpose of the
program. https://www.coloradoriverrecovery.org/general-information/about.html

Figure 2. Excerpt for UCRRIP website showing the Recovery goal.
https://www.coloradoriverrecovery.org/general-information/about.html

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Figure 3. Excerpt from UCRRIP website listing the program element if instream flow
identification and protection. https://www.coloradoriverrecovery.org/generalinformation/recovery-program-elements.html

2. Background on Endangered Fish and Flow Recommendations in the
White River.
2.1. Hydrology
The White River is a major tributary in the Green River basin. The flow regime still maintains a
snowmelt hydrograph with peak flow occurring in late May and early June. These peak flows
are most pronounced in wet and average years, however, there is a small peak flow in drier
years (Figure 4). Until the construction of Taylor Draw Dam and Kenney Reservoir in the 1980s,
the White River contained only direct flow diversion structures and no large impoundments.
Taylor Draw Dam is a run of the river facility and still passes spring peak flows through the
spillway. Anderson et al. (2019) conclude the following about the current flow regime:
The current hydrologic regime of the White River includes the annual occurrence of
relatively robust spring peak flows (Figure 7, and Appendix A) which, together with the

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current magnitude and timing of base flows, have been adequate to provide and maintain
habitat characteristics that sustain Colorado pikeminnow and razorback sucker
populations.
The flows referenced above include within and between year variation that has supported the
aquatic community in the river. Current peak flows in wet hydrologic conditions exceed 3500
cfs and reach 1000 cfs in dry hydrologic conditions. Median peak flows exceed 2000 cfs at the
Watson, Utah USGS gage (#9306500) (Anderson et al. 2019, Figure 4). The White River flow
regime and resulting habitats are adequate to support the substantial populations of
endangered and native fish species as discussed below.
Spring peak flows provide the hydraulic forces required to create and maintain habitat as well
as transport sediment from the upper river downstream through the lower river. These peak
flows also provide spawning cues for species such as Colorado Pikeminnow. High spring flows
and the shoulder flows preceding those flows inundate backwaters and embayments that are
used by the endangered fish prior to spawning. Colorado Pikeminnow use the areas as staging
locations prior to spawning. These areas are generally warmer than the mainstem river and
also concentrate Colorado Pikeminnow prey, both of which are needed for reproductive
maturation of the fish.

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Figure 4. Hydrographs presented in Anderson et al. 2019. Distribution of flows (mean daily
discharge) as measured by the USGS at the White River near Watson, Utah gage (#09306500)
for the period 1923-2016 (missing 1980-1985). The traces illustrate 90% exceedance, 50%
exceedance, and 10% exceedance values for each individual date over the period of record.
Base flows are also variable by hydrologic year type. Summer base flows in wet years are
greater than 500 cfs while flows in dry years can be as low as 100 cfs (Figure 4). White River
summer base flows are noted to have decreased somewhat with the upstream consumptive
uses for irrigation and municipalities. Irrigation return flows can be delayed as it either comes
as overland flow from surface irrigation or as groundwater return.

2.2. Fish
Studies to determine occurrence of fish species and habitat conditions in the White River in
Colorado and Utah have been conducted for several decades. These studies have documented

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the presence of endangered species, in particular Colorado Pikeminnow, since the 1970s
(Carlson et al. 1979, Lanigan and Berry 1981, Miller et. al. 1983, Irving and Modde 1994, Lentsch
et al. 2000). The White River has some of the highest catch rates of Colorado Pikeminnow in
the Upper Colorado River Basin, which demonstrates importance of the White River to the
recovery effort for that species.
In addition to the endangered species these studies also document the other components of
the biotic community including native and non-native fish species and macro-invertebrates.
The studies document the presence of all trophic levels from primary producers to top level
consumers. Native species, in addition to Colorado Pikeminnow, present include Roundtail
Chub, Speckled Dace, Flannelmouth Sucker and Bluehead Sucker. These species are consumers
of the primary and secondary producers, algae and macroinvertebrates, respectively. All of
these fish species are potential prey items for Colorado Pikeminnow.
Razorback sucker were undetected in the White River until more recent intensive monitoring
including installation of Passive Integrated Transponder (PIT) tag antenna arrays (Anderson et
al. (2019). Razorback Sucker from larval to adult age classes have been collected in the White
River since 2002 indicating the presence of suitable habitat for all life stages of that species.
Razorback Sucker feed on algae and invertebrates similar to the Flannelmouth Sucker and
Bluehead Sucker. Maintaining primary and secondary production is important to recovery of
this species.

2.3. Movement and Migration
Several researchers have studied the movement and migration of Colorado Pikeminnow
captured in the White River. Miller et al. (1983) documented migration of adult Colorado
Pikeminnow from the White River downstream to the Green River and migration from the
Green River into the White River. Colorado Pikeminnow tagged in the White River were
documented to move as much as 250 miles, which included a migration from the White River

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downstream into the Green River and return. This same study documented the movement of
Colorado Pikeminnow tagged in the Green River to an upstream location in the White River and
return to the Green River. These movements occurred during the usual spawning period for
Colorado Pikeminnow. The movement of the individual fish from the Green River into the
White River may be an indication of potential spawning habitat in the White River. The usual
period for spawning migrations is from June into early August.
Irving and Modde (2000) report migrations of as much as 400 miles for Colorado Pikeminnow
tagged in the White River. These migrations were from the White River into either the Green or
Yampa Rivers and then back to the White River. The movement out of the White River usually
occurs in June and early July. The fish return to the White River by August. This study also
reported localized movements in the White River. Late summer movements were more
localized, which would imply a home range area. This same type of localized movement was
reported by Miller et al. (1983).
Similar localized movement was reported for Colorado Pikeminnow in the Yampa River during
August to October (Miller and Rees 1997, Miller and Modde 1999). Movements of these fish
appeared to be associated with feeding in riffle habitats and movement between habitats after
dark. A study in the San Juan River reported similar movement as previous studies in the
Yampa and White rivers. Miller and Ptacek (2000) reported longer movement by Colorado
Pikeminnow during the spawning period and shorter localized movement post-spawn in late
summer.
Movement by Colorado Pikeminnow during winter is not extensively studied. Irving and Modde
(2000) report only small differences in fish locations from late fall until early spring in the White
River. Miller and Ptacek (2000) report on small movements for Colorado Pikeminnow during a
one-week observation period during February in the San Juan River. Wick and Hawkins (1989)
studied Colorado Pikeminnow habitat use and movement in the Yampa River for two winters.
They report Colorado Pikeminnow staying within the wintering area and movements of no

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more than 0.3 miles. Most Colorado Pikeminnow stayed within a specific habitat complex with
some local undirected movements.

2.4. Habitat Availability and Habitat Use
Studies to characterize aquatic habitat conditions have occurred since the 1980s similar to
those for fish studies. These studies have included habitat characterization by habitat type (e.g.
pools, riffles, runs, backwaters, etc.) as well as studies to determine change in habitat with
stream flow. The latter include studies of geomorphology (Schmidt and Orchard 2002) and
studies of change in channel physical parameters of wetted width, depth and velocity (Haines
et al. 2004).
A complex suite of habitat types is required to support a fully functioning aquatic ecosystem.
This includes habitat heterogeneity with a mix of riffles, runs, pools, low velocity habitats and a
mix of streambed substrate types. These type of habitat characteristics are currently present in
the White River. The amount of each habitat type varies by season and level of stream flow.
Backwaters, embayments and floodplain habitat is more abundant during shoulder and high
flows as these features are inundated with rising water. Pools, runs and riffles are dominant
during the base flows. All of these habitats are used by Colorado Pikeminnow and other fish at
various times of the year. Adequate flow and water depths are needed to allow production of
food and to allow the passage and localized movement inherent in Colorado Pikeminnow
behavior.
Riffle habitat is important for primary productivity which provides the food base for higher
trophic levels. Production in the riffles is highest when the greatest wetted area is maintained.
Riffle wetted area was one of the key elements examined in the habitat study by Haines et al.
(2004). Haines et al. (2004) determined the number of riffles with sufficient depth for passage
as a function of discharge and also the amount of wetted area present as a function of
discharge. A value of 30 cm was used a sufficient for unrestricted passage by Colorado

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Pikeminnow. This was the same value as used in previous determinations of minimum flow for
passage in the Gunnison River (Burdick 1997) and Yampa River (Modde et al. 1999). Anderson
et al. (2019) summarized the results of Haines et al. (2004) in the following table.
Table 1. Number of riffle cross sections with thalweg depth greater than 30 cm (Source:
Anderson et al. 2019) and percent of total passable In parentheses.
Flow in cfs

100

150

200

250

300

transects with riffle

35

43

45

46

47

thalweg depth > 30

(71)

(88)

(92)

(94)

(96)

Number of 49

cm.
Passage at riffles is important during the summer and fall base flow period for Colorado
Pikeminnow. Habitat use studies have shown that Colorado Pikeminnow can move up to a few
miles each day from a resting habitat to a foraging habitat (Miller and Rees 1997). The largest
change in the percent of riffles passable occurs as flows increase from 100 cfs to 150 cfs.
The wetted perimeter coverage also shows a similar response based on the graphs presented
by Haines et al. (2004). The greatest loss of wetted perimeter coverage occurs as flow drop
below the range of 200 to 150 cfs and lower. Maintaining wetted perimeter through the
summer growth period for fish is important to provide adequate food supply to support the fish
over winter. Greater wetted perimeter provides more area for macroinvertebrate production
upon which small bodied fishes and Razorback Sucker feed. A robust community of small
bodied and other fishes is needed to support Colorado Pikeminnow, which primarily forage on
fish as they grow from juveniles to adults. A flow regime that restricts wetted perimeter below
a somewhat typical baseflow can be detrimental to productivity and survival. Lower than
normal base flows have also been shown to be advantageous to non-native species in the
Green River basin (Anderson et al. 2019).

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2.5. White River Flow Recommendations
Studies completed from the 1980s through the early 2000s were conducted to determine the
relationship between stream flow and habitat in the White River. Most recently, there is an
ongoing effort to synthesize the available data and make updated flow recommendations for
the White River (Anderson et al. 2019). The current effort combines biological data, physical
habitat data and hydrologic data to recommend a suite of flows to maintain and benefit the
endangered fishes in the White River.
Haines et al. (2004) applied the physical habitat model RHABSIM to habitats in the White River
downstream from Taylor Draw Dam in 1995 and 1996. This model was state of the science at
the time. Newer more robust 2-dimensional hydraulic/habitat models are now the state of the
science, however, this does not diminish the usefulness of the Haines et al. work. RHABSIM
provides hydraulic data at each cross section for water width, wetted perimeter, water depth
and water velocity. The State of Colorado uses several of these parameters (wetted perimeter,
depth and velocity) to set minimum instream flows. The threshold values were first
determined by Nehring (1979) and are still applied. The thresholds for these parameters vary by
stream width (Table 2) and have been applied in many streams and rivers in Colorado.
The method used by the State is R2Cross and based on data from riffle cross sections. April
through October minimum flows are set when all three thresholds are met or exceeded. While
specific data for an R2Cross analysis was not generated from the RHABSIM model, there are
data that can be used as surrogates to calculate an approximate minimum flow similar to the
R2Cross model. Haines et al. (2004) and Anderson et al. (2019) provide data on wetted
perimeter, thalweg water depth, and velocity.

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Table 2. Key flow parameters used to determine minimum flow requirements using the
R2Cross method (from Nehring 1979).
Stream width (ft)
Average depth (ft)
Average velocity
Wetted Perimeter
(ft/sec)

(%)

1-20

0.2 or greater

1

50

21-40

0.2-0.4

1

50

41-60

0.4-0.6

1

50 to 60

61-100

0.6-1.0

1

70 or greater

Based on the above parameters and the White River riffle width, the threshold values would be
at the highest level in the parameter table. Haines et al. (2004) summarize the riffle water
width coverage for 75% water coverage. The average discharge required for 75% water width
across 42 riffles is 218.7 cfs. An analysis of the wetted perimeter graph in Haines et al. (2004)
results in a similar flow value of 221 cfs (Table 3). The average depth threshold base on the
average riffle width would be 1.0 foot. The flow value that meets this threshold in 88 percent
of more of the riffles is 150 cfs or higher (Table 1). Haines et al. (2004) do not provide
individual velocity values for each riffle at all flows simulated. They provide a summary for all
riffles at a flow of 339 cfs, 424 cfs and 552 cfs. The mean velocities at 339 cfs (the lowest flow
reported) range from 1.8 feet/second (fps) to 2.2 fps across all riffles. The mean depths at 339
cfs range from 1.2 feet to 1.3 feet (Haines et al. 2004). These values are higher than the
R2Cross parameter threshold so the minimum flow for the depth and velocity criteria would be
lower than 339 cfs and equal to or greater than the 70% wetted perimeter value of 221 cfs. The
lowest possible summer minimum flow based on the data from Haines et al. using the State of
Colorado criteria would be 221 cfs.

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Table 3. Discharge that provides 70% wetted perimeter and total wetted width for individual
White River riffle cross sections from visual estimates of graphs presented in Haines et al.
2004.

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The interim flow recommendations (Anderson et al. 2019) vary by hydrologic year type, season
and recurrence interval. Specific recommendations are made to address spring peak and
shoulder flows intended for habitat maintenance, creation, and sediment transport (Table 4).
Base flows recommendations are separated into irrigation season (Table 5) and non-irrigation
season (Table 6). The logic for the recommended flows is to continue the inter- and intraannual variation in stream flow that currently supports the robust native fish and aquatic
community in the White River, which will benefit the endangered fish. The water volumes
needed to meet these flows ranges from near 60, 000 acre-feet (90% exceedance, wet year) to
just over 8,000 acre-feet (100 % exceedance, dry year) at the USGS gage at Watson (Table 7).
The shoulder flows and spring peak flows function to support and benefit preparation and
migration for spawning fish. The irrigation base flows function to preserve and maintain the
fish passage and stream productivity needed to maintain and improve conditions for the
endangered fish. The USFWS state that the greatest change in riffle wetted perimeter and loss
of depth for passage occurs at flow less than 150 cfs (Anderson et al. 2019). The non-irrigation
season flows are intended for preserve over-winter habitat for all species including the
endangered fish. Interim flow recommendations are intended to mimic the current flow
regime in the White River at the Watson gage, which exists at the current level of water use in
the basin. The draft interim flow recommendations were derived from a combination of
hydrologic modeling and interpretation of gage data. Hydrologic modeling using the current
baseline for the White River predicted zero flow days at the Watson gage. The gage data
included a low flow in a dry year of 13 cfs. The USFWS lists the proposed instream flow at the
100% exceedance value in dry year of 30 cfs for the 139-day June 15-October 31 time period to
avoid extremely detrimental conditions to the endangered species. The flow volume to meet
the 30 cfs flow would require 8257 acre-feet of water, not accounting for transit loss or
evaporation during the irrigation season. For comparison, a higher minimum flow of 150 cfs for
139 days that maintains riffle passage and productivity at the level prior to the greatest decline,
would require 41,283 acre-feet of water at the Watson gage during the irrigation season.

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Additional consumptive use is predicted based on future growth in the Whiter River basin,
which would reduce streamflow downstream from those uses from those now reported for
current conditions. The interim flow recommendations are a stepped function that results in a
different flow exceedance value is the river is managed down to the recommendations (Figure
5). The ability to maintain and recover the endangered species would be impacted if flows are
reduced from current conditions. Increased demand and consumption without augmentation
in downstream river reaches could shift the hydrologic regime to a drier condition and less
beneficial conditions for the endangered species. Maintaining the flow at a minimum of 150 cfs
for all conditions shown in the shaded portion of Table 5 for Average, Moderately Dry and Dry
year types would be more beneficial to the endangered fish.
Table 4. Recommended spring peak and shoulder flows by hydrologic year type from
Anderson et al. (2019).

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Table 5. Recommended irrigation season base flows by hydrologic year type from Anderson
et al. (2019).

Table 6. Recommended non-irrigation season base flows by hydrologic year type from
Anderson et al. (2019).

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Table 7. Flow volume (acre-feet) required for each interim instream flow recommendation
from Anderson et al. 2019.

Figure 5. Flow duration curve for White River at Watson gage from June 15 to October 31 of
four “dry” years as presented in Anderson et al. 2019.

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2.6. Future White River consumptive and non-consumptive water demands and the Rio
Blanco Water Conservancy District proposed storage water right.
An ongoing effort is in place to develop a Management Plan for the White River as well as a
Programmatic Biological Opinion (PBO) to address future water development in the basin. This
same approach of developing a management plan and PBO has been applied on the Colorado,
Yampa and Gunnison rivers. This approach fits with the dual goals of the UBCRRIP to recover
the endangered fishes and allow water development to proceed according to federal and state
laws. An estimate of future development and consumptive use as well as the amount of water
needed to support environmental flows is part of this process. The scenarios include a range
for projections from low levels of new demands to high levels of new demands. The Colorado
Water Plan makes predictions for water use to the year 2050. The projections include
predicted increases for Municipal & Industrial use and energy development. Energy
development includes both Oil and Natural gas and Oil Shale. An increase in future water use
could reduce the frequency and occurrence of the current flows. The Rio Blanco Water
Conservancy District has made an application for storage water rights for Wolf Creek Reservoir
that includes releases of stored water for maintenance and recovery of federally listed
threatened and endangered species. The amount of water specified for endangered fish flows
is 42,000 acre-feet (Wheeler 2015) but could range from 21,283 acre-feet to 208,850 acre-feet
to meet the endangered fish augmentation requirements (Wheeler 2020). The total maximum
long-term needs for M&I, Oil and Natural Gas, and Oil Shale is listed as 48,950 acre-feet
(Wheeler 2015, Wheeler 2020).

3. Summary and Opinion
The White River is a major tributary in the Green River basin. The endangered species that are
found in the White River are part of a larger metapopulation within the Green River basin and
its tributaries. The importance of the White River to the recovery of the endangered species is

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noted in Tyus and Saunders (2001) and Lentsch et al. (2000). The White River currently
supports all life stages of Colorado Pikeminnow and reproduction by Razorback Sucker was
documented in recent years. The presence and increase in the numbers of these fish
demonstrate the importance of the White River to recovery of these species. The current
populations are the result of the habitat and flow conditions in the river with current levels of
use.
Colorado Pikeminnow use a wide range of habitats depending on season and activity. Some
Colorado Pikeminnow also make long spawning migrations during summer from the White
River to known spawning locations in other portions of the Green River basin. Colorado
Pikeminnow also move within shorter river reaches during late summer and fall to feed in
riffles. Some of these movements require passage through several riffles on a daily or weekly
basis. Razorback Sucker feed on periphyton, algae and invertebrates and these prey items are
generally found in or near riffle habitats. It is important for the recovery of the endangered
species to keep these riffle habitats passable and productive. The USFWS state that research in
the White River has shown that a flow of 150 cfs is the point at which the decline in riffle
habitat and depth becomes greatest (Anderson et al. 2019).
The flow regime in the river today still retains a relatively natural snow-melt runoff shape with
inter- and intra-annual variation. These variations provide the range of conditions that
maintain the habitat and support the aquatic species, including endangered species, in the
river. Future water consumptive use, as projected, in the White River without augmentation
would reduce the flow volume and potentially seasonal timing of flows to the detriment of
endangered species. Fish monitoring data in the Upper Colorado River Basin under current
conditions has shown that extreme low flows in dry water years favor some non-native species,
such as Smallmouth Bass, and are not beneficial to native fish. The USFWS interim flow
recommendations list a flow of 30 cfs should be the flow met 100% of the time in dry years.
The USFWS acknowledges that this low flow while preventing complete drying of the river may
result in increased non-native populations and result in less productivity and riffle passage.

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The UCRRIP has the dual objective of recovery of endangered species and allow water
development to proceed in accordance with federal and state laws. It is important to note the
objective of “recovery” of endangered species is not to maintain the status quo (i.e.
endangered status but avoid extinction). The UCRRIP identified several elements to recover the
endangered fish. One of these elements is to identify, provide and protect instream flows to
maintain and benefit endangered species. Identification and providing water to meet
recommended instream flow regimes has occurred in the Colorado, Gunnison and Yampa rivers
through the use of reservoir releases. Yampa River summer base flows are augmented with
water specifically for endangered fish benefit from Elkhead Reservoir.
In conclusion, it is my opinion that the interim flow recommendations for peak flows and
shoulder flows are appropriate to maintain and benefit the endangered fish in the White River.
The flows are typical of the magnitude and timing of the current peak and shoulder flow
regime, which create and maintain habitat, provide spawning cues, and opportunities for
migration.
It is my opinion that separation of base flows into irrigation and non-irrigation seasons is
appropriate. The endangered species use habitat differently in summer and winter, which
require different levels of flow. Mid-summer is the time when migrating Colorado Pikeminnow
return to the White River and passage over riffles is critical to the return to their home ranges.
Summer and fall are the seasons when water temperature and food availability promote
growth for aquatic biota, including the endangered fish, to prepare the species for the colder
winter months. Movement through and within riffle habitat is critical for feeding and growth.
It is my opinion that maintaining summer base flows at a minimum of 150 cfs is more likely to
assist in recovery of the endangered species than the lowest flows specified in dry years. Fish
passage and riffle wetted perimeter are substantially higher at 150 cfs than at flows of 100 cfs
and lower. The hydrologic modeling and gage analysis show that the 150 cfs flow is not

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available at all times, which would require augmentation of flows. Wolf Creek Reservoir would
have water specifically available for release to benefit the endangered fishes. Further, it is my
opinion that the projected additional future water consumption in the White River over current
conditions would require augmentation of flows to meet the USFWS interim flow
recommendations. The predicted long-term future non-irrigation uses are as much as 48, 950
acre-feet (Wheeler 2015, Wheeler 2020). Future water demands and use at that level would
require a commensurate release to meet the interim flow recommendations.
The Rio Blanco Water Conservancy District has applied for a storage right for Wolf Creek
Reservoir that includes a specified use for maintenance and recovery of endangered fish that
could offset the stream flow reduction due to future demands. It is my opinion that the best
reservoir site for releases to benefit endangered species in the White River downstream from
Taylor Draw Dam would be a location upstream of and close to Kenney Reservoir. The Wolf
Creek Reservoir location meets these criteria.
It is my opinion that the minimum flow in the White River to benefit endangered fishes is 150
cfs. A flow of 150 cfs keeps the majority of riffles passable by Colorado Pikeminnow and
productive for food resources consumed by Colorado Pikeminnow and Razorback Sucker.
It is my opinion that additional releases will be needed to meet these criteria in certain average,
moderately dry and dry years. The water volume needed would range from approximately
21,000 acre-feet (50% exceedance dry year) to over 41,000 acre-feet (100% exceedance dry
year) at the Watson Gage, not including transit loss and evaporation (Table 8).
Table 8. Acre-feet volume required to meet the 150 cfs recommended minimum flow during
irrigation season in average, moderately dry and dry years.

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It is my opinion that the storage right for Wolf Creek Reservoir will needed for the additional
releases to meet the recommended flows for maintenance and recovery of endangered fishes.

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