CHEYENNE BOARD OF PUBLIC UTILITIES OPERATING PERMIT RENEWAL

Water Resources Report

Prepared by:

/s/Carol Purchase Carol Purchase

Hydrologist 307-326-2543

cpurchase@fs.fed.us Date: 02/28/2012

Brush Creek/Hayden Ranger District Medicine Bow-Routt National Forests Thunder Basin National Grasslands P.O. Box 249, Saratoga, WY 82331

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Cheyenne Board of Public Utilities Water Facilities Reauthorization

Water Resources Report By Carol Purchase, February 28, 2012 Introduction The City of Cheyenne Board of Public Utilities (CBOPU) has had a water collection and storage system on the Medicine Bow NF since 1962. In 1962, the original water collection and storage facilities were authorized for the purpose of operation and maintenance of two reservoirs, 21 miles of pipeline and a 3,300 foot long tunnel (Stage I). The system was expanded in 1964 to add a third reservoir. The entire system was increased in size and extent in the1980’s following the preparation of an Environmental Impact Statement (EIS) for the Stage II Development of the Water Collection Facilities of the CBOPU. A Record of Decision (ROD) was signed for this action on December 8, 1981. The Stage II development was authorized under an easement issued on July 26, 1982. The 30 year easement is expiring and the CBOPU has applied for renewal of the easement. Proposed Action The proposed action is to issue a new authorization to CBOPU for the operation and maintenance of the water collection, transmission and reservoir system owned and operated by CBOPU on NFS lands. The period of the new authorization is proposed to be 30 years. Design criteria would be developed for additional protection of the environment beyond that provided by standard authorization clauses. The design criteria will be tied to the authorization through an operation and maintenance plan. Existing facilities currently covered by the easement include:

126 concrete diversion structures

3,500 foot long tunnel crossing under the Continental Divide.

About 26 miles of concrete and steel pipelines, with a combined flow capacity of about 240 million gallons of water per day. This system is used to transport water collected by the diversion structures located along the west side of the Continental Divide, into Hog Park Reservoir, which is located on the east side of the continental divide.

Hog Park Dam and Reservoir, which impounds 22,600 acre feet of water behind a 120 ft. high dam.

Rob Roy Reservoir, which impounds about 35,600 acre feet of water behind a 140 ft. high dam. Some of the land around Rob Roy Reservoir is owned by CBOPU, including the dam location.

Lake Owen Dam and Reservoir which impounds about 700 acre feet of water behind a 12 foot high earthen embankment.

About 24 miles of concrete and steel pipelines, with a flow capacity of about 26 million gallons of water per day, which are used to transport water from Rob Roy Reservoir to Lake Owen Reservoir. From Lake Owen the water is transported to the Cheyenne area through two steel pipelines with a combined flow capacity of about 26 million gallons of water per day.

Necessary access roads.

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The right-of-way widths are limited to 100 feet in width. The rights-of-way for reservoirs, dams and appurtenant structures are limited to the area actually occupied.

Purpose and Need The purpose of this action is to provide a new authorization for existing facilities on NFS lands, for which a demonstrated public need has been shown. The need of the action is to allow CBOPU to continue to operate its water collection and transmission system to provide water to the residents and businesses of the City of Cheyenne, the South Cheyenne Water and Sewer District, and Warren Air Force Base. About 60% of Cheyenne’s water comes from the system located on NFS lands. The rest comes from four wells located around the City of Cheyenne. No new construction of collection or transmission facilities is proposed for the new authorization. Existing Condition The operations of this water system have been monitored by the U.S. Forest Service and found to be in compliance with the easement conditions (USFS, 2011a). The focus of this report is to compare the existing condition to the expected effects described in the Cheyenne State II Water Diversion Proposal FEIS (FEIS) (USFS, 1981) and to review current existing conditions to determine compliance with the relevant water and aquatic standards and guidelines in the Medicine Bow Revised Forest Plan (USFS, 2003) and with existing laws and regulations. Soil erosion, such as that occurring on the Rob Roy lake shore, and from unauthorized ATV use of the pipeline access are not covered in this report, but are addressed in the Soil report (USFS, 2011b). Likewise, effects of this water system on aquatic life and aquatic habitat are covered in the Aquatics report (USFS, 2012). Douglas Creek Watershed Douglas Creek has been altered by human activities for two centuries. Early in the 1800's, trappers removed beavers from the drainages, reducing wetlands and pools along the major drainages (Young et al, 1994). Between 1870 and 1940, railroad ties were driven down Douglas Creek and many other creeks and rivers in the Snowy Range. To drive the ties down the stream channel, logs and boulders were removed, often with dynamite. Tie drives widened and straightened stream channels, reducing pools and habitat complexity (Young et al, 1994). Gold mining along Douglas Creek started in 1868 and has continued in one form or another ever since (westernmininghistory.com). Suction dredging, both with large machinery or small equipment has occurred over the past century. The effects of the ongoing small scale suction dredging still can be seen in the summer as piles of gravel from the recreational gold miners dot Douglas Creek from Keystone to below the confluence with Lake Creek. Reservoir Release Effects on Spring Runoff Hydrograph The original Rob Roy Reservoir was completed in 1966, and the capacity of the dam was approximately one-third of the average annual runoff of Douglas Creek. A USGS gage (active from 1955 to 1965) was located above Keystone and approximately 1 mile below the current Rob Roy dam. The drainage area above this gage is just slightly larger than the drainage area1 of Rob Roy Reservoir and so the flows should be very similar to the natural flows in the Rob Roy Watershed. Figure 1 below gives the peak flow data from 1955 to 1965 for this gage. Peak flows averaged about 575 cfs, and vary between 390 cfs in 1964 to over 850 cfs. (Note that USGS data indicates that several years in the early 1960's were low peak flows for most

1 The USGS gage has a watershed area of 22.10 square miles, the watershed area above the Rob Roy

dam is 21.0 square miles (MBRTB GIS database).

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creeks in the Snowy Range.)

Figure 1. Peak flow data for Douglas Creek above Keystone for the years 1956-1965. (USGS Data for Wyoming: http://waterdata.usgs.gov/wy/nwis/sw)

There is no data for the gauging station above Keystone after 1965, but peak flow data for the USGS gage downstream on Douglas Creek (located below the confluence of Pelton and Douglas Creeks) shows that high peak flows did not appear to decrease significantly after this dam was in operation in the early 1970's (Figure 2.), likely due to the small storage capacity of the reservoir in relation to the total watershed runoff. This figure also shows the representative range of high flows that have historically occurred in Douglas Creek.

Figure 2. Peak flow data for Douglas Creek near Foxpark for the years 1947-1972. (USGS Data for Wyoming: http://waterdata.usgs.gov/wy/nwis/sw)

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The reservoir enlargement in 1987 increased the capacity to enable storage of more than one year of average annual runoff from the watershed. Looking at the flows below Rob Roy Reservoir, measured by CBOPU2, the increased storage capacity appears to have the result of reducing the average peak flow below the reservoir. Figure 3 shows that during average or low snowpack years, the peak flows are at or slightly above 130 cfs, the 'flushing flow' required by the easement conditions. The easement also allows higher natural flows to be released, as occurred in 2010 and 2011 during very high snowpack years. Spring runoff in 2010 and 2011 resulted in 100 year return interval flows on many of the streams and rivers in the area, however the flows released by Rob Roy Reservoir were closer to the pre-dam average peak flow (2 year return interval) than to a 50 or 100 year flow event (USGS Data for Wyoming: http://waterdata.usgs.gov/wy/nwis/sw). From these lower than expected flows, it appears that the Rob Roy Reservoir expansion has reduced peak flows along Douglas Creek and reduced overbank flows, as can also be seen by the presence of lodgepole and other upland vegetation growing on the floodplains along Douglas Creek below the reservoir (USFS, 2006). This reduction in peak flows during very high snowpack years has also likely contributed to reduced flooding in the Keystone area, reducing flood damage to the cabins and summer homes that are located along Douglas Creek below the reservoir. Under pre-dam conditions it would have been very probable that the flows in Douglas Creek in 2010 and 2011 would have been similar to the high flows shown in Figure 1, which are 40 to 50% higher than flows measured in 2010 and 2011.

Figure 3. Peak flow releases from Rob Roy Reservoir 2004-2011.

Additionally, the reduction in peak flows has led to the stream channel being over-wide in comparison to the current average peak flows. A study of habitat in Douglas Creek found that the stream channel is on a very slow trend towards narrowing, however with the limited sediment supply due to the upstream reservoir, it will take a long time (50 + years) for the channel to narrow sufficiently to adjust to the current flow regime (Wesche, 1987).

2 There has been no active USGS streamgage on Douglas Creek since 1974.

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Figure 4 displays the spring hydrograph releases from Rob Roy Reservoir for 2004 to 2011 (CBOPU data). During high flow years, the flow releases from Rob Roy Reservoir resemble natural hydrographs for the area, with a fairly gradual declining limb of the hydrograph. During lower flow years, such as the drought years of 2003 and 2004, the 'flushing flow' of 130 cfs was released, as stipulated in the permit, however no extra water was available for a higher flow release, resulting in an abrupt ramping up and down of the flow to conserve water. The pattern during low flow years would result in an unnatural sediment deposition pattern for the smaller streambed materials (sands and gravels). The slow declining flow rate during high flow years would result in more natural sediment deposition pattern in Douglas Creek.

Figure 4. Spring runoff hydrograph releases from Rob Roy Reservoir 2004-2011.

Effects on Low Flows The original dam completed in 1966 reduced lows flows during late summer and fall to about two to three cubic feet per second (cfs) from the natural daily mean flows from 4 to 8 cfs for late summer and fall (USGS daily mean statistics for USGS station 06620400). The reservoir enlargement in 1987 increased the minimum flow to 5.5 cfs from the 1 cfs required for first reservoir. This resulted in restoring the minimum flows to be very similar to the pre-dam natural minimum flows during late summer and fall, and likely slightly increased minimum flows over natural flows during winter and early spring (USFS, 1981). Effects on Wilderness Values Douglas Creek above the reservoir is approximately 21 square miles, which is about 1/6th of the watershed above the Savage RunPlatte River Wilderness (120 sq. miles). Peak flows through the wilderness do not appear to have been altered by the reservoir as it only affects a small portion of the watershed above wilderness. The Savage RunPlatte River Wilderness was

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established in 19781984, when the low flows from Rob Roy were between one and two cfs, which was less than the natural daily mean low flow range of approximately 4 to 8 cfs. The 1987 enlargement of Rob Roy increased minimum flows in Douglas Creek to 5.5 cfs, which has slightly increased low flows in Douglas Creek through the wilderness. The operation of the reservoir since the enlargement does not appear to have affected wilderness values related to Douglas Creek in the Savage RunPlatte River Wilderness. Effects on Douglas Creek Streamchannel Stream channel erosion related to Rob Roy reservoir operations has only been observed just below the reservoir on lands owned by the City of Cheyenne. In the late 1980's, bank and stream channel structures were placed in this section of the creek to stabilize the channel, and have been effective. Downstream, on NFS lands, the stream channel is naturally armored with boulders above the Keystone area. The lower gradient reaches of the stream do not appear to have erosion related to flow releases. These portions of the stream channel continue to be affected by suction dredging, which leaves piles of gravels and cobbles in the stream channel each summer. During high flow years, the higher flow releases, and gradual declining rate of flow likely re-distribute the stream channel materials to a more natural form with pools and point bars. Effects on the Tributaries of Douglas Creek Collection points along the pipeline leading from Douglas Creek to Lake Owen divert water from Horse Creek, and tributary streams of Little Beaver and Muddy Creeks - all of which flow into Douglas Creek. Minimum flows were established for the collection points on perennial streams and three day 'flushing' or high flows are released during spring runoff for these streams. The effects on these streams and Douglas Creek appear to be consistent with description in the environmental consequences section of the 1986 EIS analysis. Desired Conditions The desired conditions in Douglas Creek is to have the channel width and channel capacity to narrow sufficiently, so that it is sized to the currently peak flow regime so that overbank flows would occur every 2 to 5 years. With a narrower stream channel pools would deepen and the channel would have more cover from riparian vegetation, which would improve aquatic habitat. Recommendations The following measures were developed to meet forest plan standards and applicable laws and regulations.

Retain bypass flows for the diversion structures and the minimum flows of 5.5 cfs for Rob Roy Reservoir.

Adopt the existing Region 2 clause (R2-D101) to release 5 days of high flows for the diversion structures which collect water for CBOPU. This could be conditional on the water year - for example, require the 5 days of high flow releases for high snowpack years, and the current 72 hour release required for low snowpack years.

For higher snowpack and/or water storage years: Release high flows within the normal high flow period (May 10 to June 30) and with a declining hydrograph rate (when flows are at bankfull or below) that would simulate rates found in un-regulated systems. This is consistent with existing operations as shown in Figure 4. This will result in natural sediment transport and deposition processed to occur during high flow years.

For low snowpack and/or low water storage years, retain the current operations of releasing 130 cfs with no ramping rate requirement.

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The definition of low versus high snowpack and/or water storage years should include both available water storage and snowpack and should be determined cooperatively with CBOPU.

Recommended Monitoring After 10 years, analyze the spring flow releases from Rob Roy Reservoir (using the annual data from the existing CBOPU flow measurement station) and adjust operations if natural hydrograph flow patterns are not occurring during periods when excess water is available. Hog Park Watershed Hog Park Reservoir stores water collected from the Little Snake Watershed and releases it into Hog Park Creek, where it flows down the Encampment River into the North Platte River to replace water taken from Douglas Creek in the North Platte Watershed. Since this reservoir is operated to move extra water through the system, rather than store water for later use (as is the case for Rob Roy Reservoir), it has both minimum flows and high flow releases set higher than would occur naturally. A minimum flow of 15 cfs is released from the reservoir into Hog Park Creek, which is higher than the natural low flows by about 10 cfs. High or 'flushing flows' of 200 cfs are mandated to be released for 72 hours; however natural inflows may and have exceeded this amount. Under the current permit, the Little Snake diversion water is allowed to be released when total reservoir outflow is under 200 cfs, however releases of this transbasin water is not allowed under the current easement when natural inflows are above 200 cfs. The FEIS (USFS, 1981) analyzed a flow release pattern for the stored Little Snake water that assumed the extra water would be released both during the higher than natural low flows (15 cfs as compared to estimated pre-dam natural low flows of 5.5 cfs) and during the high flows of 200 cfs during the spring runoff period, which were predicted to be about 100 cfs higher than natural average peak flow. The FEIS also anticipated that Hog Park Creek channel would widen initially, in response to the higher peak flows. Reservoir Release Effects on Spring Runoff Hydrograph As mentioned above, the FEIS predicted that spring peak flows would be higher than prior to the reservoir enlargement, but did not predict a change in timing of high flows. Figure 5 displays mean daily flows for several creeks of a similar size and elevation to Hog Park Creek, in addition to the Encampment River above Hog Park (which is close to Hog Park Creek, but has a watershed about three times larger than Hog Park Reservoir). All the unregulated streams have similar timing of both peak flows and when flow begins to increase in the spring. Even South Brush Creek, which is located on the Snowy Range, is similar in timing to the headwaters of Battle and the Little Snake River, which are located just to the west of Hog Park Creek. Hog Park reservoir has been operated so that flow often increases several months earlier than would occur naturally, when unregulated streams have low flows and are under snow cover. The spring high flow releases from Hog Park Reservoir have not had a typical hydrograph pattern, or a very consistent pattern as seen in Figure 6. Flow releases from Hog Park Reservoir are compared to a typical unregulated hydrograph from Battle Creek (in black). Flow is typically released several months earlier, and often has had sustained flows at levels between 100 and 200 cfs, which correlate to flows at half to almost full bankfull over several weeks or longer. Additionally, the rate of increase and decreasing flows are more abrupt, especially the rate of flow decrease is higher than occurs naturally in unregulated streams. Spring hydrograph analysis found that the rate of flow decline has increased 113 percent from pre-dam conditions (Gilliam, 2011).

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Figure 5. Mean daily flow for Hog Park Creek (in black) compared to unregulated streams.

Figure 6. Spring peak flow releases from Hog Park Reservoir compared to Battle Creek spring hydrograph (in black).

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Effects on Stream Channel While the FEIS predicted that Hog Park Creek would widen initially, the creek has continued to show signs of bank erosion and widening more than 25 years later. To measure stream channel changes below the reservoir, stream channel monitoring was initiated in 2004. Stream channel cross-sections and erosion pins were installed in three sites along Hog Park Creek below the reservoir. A monitoring site on S. Fork Hog Park Creek was also established to act as a control stream reach. The initial monitoring was built upon by a master's thesis (Gilliam, 2011), which analyzed stream channel changes over time and bank erosion processes. The relevant results of these studies are described below. Figure 7 below shows the locations of the monitoring sites. Site 1 is located in a broad wet meadow about 1/2 mile below the reservoir. Site 2 is located in a broad meadow complex downstream of a small canyon. Site 3, (otherwise known as Hog Park below S.F. Hog Park Creek), is located on Hog Park Creek, below the confluence of S. Fork Hog Park Creek in the same meadow complex as S. Fork Hog Park and Site 2. All of the sites are located in similar soils, vegetation, valley types and stream gradient.

Figure 7. Location of monitoring sites along Hog Park and South Fork Hog Park Creeks.

Stream channel monitoring results are displayed in Figure 8. Straight sections of stream channels generally do not change in width as compared to bends and meanders. For this analysis, only the cross sections on the straight sections of the creeks were compared to reduce the complexity of natural streamchannel processes within meanders. Stream channel monitoring results have revealed that Hog Park Creek widened between 2004 and 2007, while the S.F. Hog Park stream channel area decreased slightly during this time period (Figure 8). Using the nearby USGS stream gage on the Encampment River above Hog

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Park Creek as an indicator of peak flows, the peak flows during these years were generally low - between two and five- year return interval peak flows or less. The exception was 2006, which had a peak flow equal to about a 25 year return interval. The lack of high spring peak flows correlates with the negligible channel change measured in S.F. Hog Park Creek. Channel widening in both Hog Park and South Fork Hog Park creeks occurred between 2007 and 2011, which is not surprising given the two years of peak flows which exceeded the 100 year flood event in 2010 and 2011. The most channel change was measured on Hog Park Creek in Site 1. Site 2 did not see as much change as the other two sites on Hog Park Creek, although the stream channel changed laterally across the floodplain more than in any other site. Site 3 is located below the confluence with S.F. Hog Park Creek, and has had more channel widening between 2004 and 2007 than between 2007 and 2011, which is inconsistent with what would be expected from the natural peak flows during these two time periods. The increased channel capacity has resulted in higher flows being necessary to achieve overbank flows. Currently, the 200 cfs high flow stipulated in the current permit results in flows near bankfull, which will continue to erode the stream banks if that level of flow is sustained for a prolonged duration. Wetlands adjacent to the stream channel in the floodplains along Hog Park Creek are being impacted as the channel widens into the wetlands, and also from the reduction in overbank flows which would normally flood the wetlands adjacent to the creek.

Figure 8. Measured channel change in Hog Park and S. Fork Hog Park Creek.

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Stream bank erosion processes in Hog Park Creek were studied by Gilliam for her master's thesis (Gilliam, 2011). One of the major factors thought to contribute to the stream channel erosion is the rapid decline in flows which dropped the water level faster than the water could drain out of the streambanks, leaving saturated soils perched above the water table. Saturated soils have less strength than drier soils, which can result in bank sloughing (Henderson, 2006). Studies of freeze-thaw cycles on soils also have measured increased erosion of streambanks that are exposed to freeze thaw cycles (Ferrick et al, 2005, Henderson, 2006). With the flow fluctuating from March through mid May, the snow is melted off the streambanks, exposing the banks to the extreme temperature variations common during springtime at this elevation. Unregulated creeks during this time period are completely covered with snow and so have a more constant temperature regime. The studies on Hog Park Creek indicate that the flow release pattern appears to be increasing stream channel erosion as compared to the control stream reach. The following factors appear to be the primary mechanisms leading to the increased bank erosion (Gilliam, 2011):

Decreasing flows at a rate higher than water can drain out of the saturated stream banks. This leaves saturated streambanks with little structural strength perched above the water level, which can lead to bank sloughing.

Sustained high flows at three quarters to bankfull which can result in channel widening.

High flows after banks are thoroughly saturated, such as when high flows occur after flows had been sustained at near bankfull conditions, can cause increased bank erosion over high flows with dryer bank conditions (Henderson, 2006).

Exposed stream banks during early spring when there are large daytime to nightime temperature fluctuations. The streambanks are exposed when snow cover is removed during bankful flows. The exposed streambanks are more susceptible to freeze-thaw cycles, which reduce soil stability (Ferrick et al, 2005).

Effects on Low Flows in the Encampment River The minimum flow of 15 cfs is more than double the flow than would naturally occur in Hog Park Creek during late summer, fall and winter. Figure 9 compares the mean daily streamflow in the Encampment River near the town of Encampment downstream of Hog Park Creek for the periods before and after the reservoir enlargement. This data indicates that the flow in the Encampment River is 15 to 20 cfs higher during low flow periods than prior to the enlarged dam. The exception is during mid to late summer, when irrigation ditches are diverting the available streamflow. This flow comparison also shows the early spring flow increase from the Hog Park flow releases in March through May. The lower mean peak flow shown is due to several very high peak flows in the 1940's and 1950's and is likely not a result of reservoir operations.

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Figure 9. Mean daily flow in the Encampment River near Encampment, WY before and after the enlargement of Hog Park Reservoir.

Effects on Wilderness Values in the Encampment Wilderness This change in flow pattern has likely increased available aquatic habitat during low flow periods in the Encampment Wilderness, which is above irrigation diversions. The increase in peak flows is likely not significant due to the relatively small contribution of the Hog Park Reservoir (about 12 sq. miles) related to the Encampment watershed above Hog Park Creek (72 sq. miles). Also, the reservoir is operated to increase water into the system, rather than decrease flows, so high flood flows in the Encampment are still occurring naturally. Desired Conditions The desired conditions in Hog Park Creek are to have the reservoir releases resemble a natural spring flow hydrograph and to have the releases occur within the normal range of high flows for the elevation. The desired condition for the stream channel is to reduce streambank erosion and have the stream channel on a trend towards decreased width, until the stream channel capacity and morphology are aligned with the current peak flow regime. With a narrower stream channel, pools would deepen and the channel would have more cover from riparian vegetation; both of which would improve aquatic habitat. Impacts to the wetlands along Hog Park Creek would be reduced as the channel narrows, so that loss of wetlands would no longer occur. Recommendations:

Retain minimum flows of 15 cfs for Hog Park Creek.

Release high spring flows to resemble a natural hydrograph for the area, within the normal peak flow season for the elevation. The following is the recommended flow release pattern to meet this goal:

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Hog Park Reservoir Flow Releases: Remove flushing flows requirement of 200 cfs and replace with the release 5 days of natural high runoff clause. Release high flows within the normal high flow period (May 15 to July 10), with declining hydrograph rate similar to rates found in unregulated systems. Allow release of stored Little Snake Water until natural inflows reach 325 cfs. Recommended Ramping Rates (or higher if natural inflows are higher):

Ascending hydrograph - up to: 50 cfs/day Descending hydrograph above 250 cfs: 25 cfs/day > 150 and < 250 cfs: 15 cfs/day < 100 cfs to 60 cfs: 10 cfs/day below 60 cfs: 5 cfs/day

Flows above 35 cfs should be either ramping up or ramping down, and not sustained at levels between 35 and 250 cfs as this is likely one factor causing high bank erosion. Observations of flows at 35 cfs could indicate if a higher flow level could avoid increasing bank erosion, currently 35 cfs is the best estimate from the available data. Note: These rates could be adjusted if monitoring or faster declining rates results in a normal sediment deposition pattern and reduced bank erosion.

If it becomes necessary to know the rate or amount of incoming inflows to the reservoir with greater accuracy than can be measured from the change in reservoir level, install a measuring device on Hog Park Creek where it flows into the reservoir.

Recommended Monitoring After 5 years, analyze the spring flow releases from Hog Park Reservoir (using the existing CBOPU flow measurement station) and adjust operations if natural hydrograph flow patterns are not occurring during periods when excess water is available. In 5 years repeat current stream channel monitoring measurements to determine if flow release pattern modifications are having the desired results. If CBOPU would like to experiment with different flow release patterns, these measurements could be repeated more frequently. Lake Owen Water on the way to Cheyenne flows into Lake Owen, and then down through the pipeline to Pole Mountain. The lake level is kept stable as the lake is not used for storage. The lake is a popular recreation site and so is stocked regularly by the Wyoming Game and Fish Department. In the summer of 2010, the lake experienced a fish die-off event. Continuous flow through the lake did not occur steadily throughout this summer, due to the high amount of natural runoff from the high snowpack year. It is unknown if adverse temperature and/or dissolved oxygen levels were compounded by the lack of flow through during the summer months due to a lack of monitoring. Desired Conditions Maintain water quality conditions sufficient to support a cold water fisheries in Lake Owen.

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Recommendations

Retain the clause in the permit which requires that the Lake Owen lake level is maintained at an elevation of 8,948 feet.

Add a flow through or inflow requirement of 1.0 cfs with provision that when this is not feasible, CBOPU cooperates with the WYG&F on a monitoring program to determine when temperature and/or water quality conditions contribute to loss of fisheries.

Little Snake Watershed A series of diversion structures along a pipeline take water from tributaries of the Little Snake River to Hog Park Reservoir, to replace water taken from the Douglas Creek Watershed on the Snowy Range. All but one of the streams with Colorado River Cutthroat Trout habitat streams have bypass (minimum flows) designated, and during spring runoff, 3 days of high flows are released down these stream channels as well. Standard Creek is the only stream known to provide CRCT habitat that does not currently have a designated minimum flow. Recommendations for a minimum flow are discussed in the Aquatics report (2012). The minimum flow for Solomon Creek in the existing easement is 1.0 cfs. The original plan was to have one diversion on this creek. However, when the system was built, the actual location of the road and pipeline was uphill slightly, which resulted in diversion structures on both East and West Solomon Creeks. These diversions have bypass flows of 0.5 cfs, which results in the same amount of bypass flow for Solomon Creek as stipulated in the easement. This diversion system appears to be operated as predicted by the FEIS. The disturbed areas have stabilized, and are vegetated, minimizing the current effect of these facilities on water quality and wetlands. Desired Conditions Perennial streams with collection structures should have high flows sufficient to move sediment and maintain channel processes and should have year round flow downstream of the collection points. Recommendations:

Maintain all existing bypass flows with the following exception: change Solomon Creek minimum flow of 1.0 cfs to E. Solomon 0.5 cfs, W. Solomon 0.5 cfs in the new permit (this is consistent with current operations).

Adopt the existing Region 2 clause (R2-D101) to release 5 days of high flows for the diversion structures which collect water from the Little Snake Watershed. This could be conditional on the water year - for example, require the 5 days of high flow releases for high snowpack years, and the current 72 hour release required for low snowpack years.

Establish a bypass flow for Standard Creek as recommended in the Aquatics Report (2012).

Crow Creek Watershed The pipeline from Lake Owen discharges water into the South Fork Middle Crow Creek (Bamford Creek). The existing permit has the following stipulation concerning the flow releases into Bamford Creek:

Annually prepare a full augmentation plan for Bamford Creek (South Fork Middle Crow Creek) for approval by the Forest Supervisor. Flow releases into Bamford Creek during the first year of

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operation will not exceed 1 cfs at each drop point or more than 2 cfs from all drop points. Releases after the first year may be increased only if it is determined that higher flows will not cause undesirable flooding or bank erosion. Releases from all drop points totaling more than 8 cfs. will not be approved. Releases will not be made during a period of peak spring runoff.

The flow discharges under the existing permit have not created additional erosion and have contributed to good fish habitat (WYG&F, 2011). Public use has increased, which has led to increased impacts from off road use; however this is a Forest Service travel management issue and not related to CBOPU facilities or operations.

Desired Conditions Bamford Creek has a stable stream channel and riparian area which resemble natural conditions for streams in the area.

Recommendation: Continue current operations as required by 1982 easement.

Forest Plan Consistency The following are the relevant Water and Aquatic standards from the Medicine Bow NF Revised Land and Resource Management Plan (USFS, 2003).

Water and Aquatic Standard 6:

Conduct actions so that stream pattern, geometry, and habitats maintain or improve long-term stream health.

Water and Aquatic Standard 8:

Manage stream flows under appropriate authorities to minimize damage to scenic and aesthetic values, fish and wildlife habitat and to otherwise protect the environment.

Water and Aquatic Standard 9:

Manage water-use facilities to prevent fully erosion of slopes and to prevent sediment and bank damage to streams.

Water and Aquatic Standard 14:

Design activities to protect and manage the riparian ecosystem. Maintain the integrity of the ecosystem including quantity and quality of water.

Current operations appear to not be consistent with Forest Plan standards due to the continuing widening of Hog Park Creek, the lack of streamflow in Standard Creek during portions of the year due to no bypass flow. If the recommendations in this and the Aquatics report (2012) are adopted, Forest Plan Standards will likely be met by CBOPU operations.

Consistency with other Laws and Regulations Consistency with Wetlands/Floodplains Executive Orders:

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Current operations are resulting in loss of wetlands along Hog Park Creek due to stream channel widening and bank erosion. Floodplain function could be lost as well if the stream channel enlarges such that overbank flows no longer occur. The recommended changes in flow release patterns should result in reduced bank erosion which would limit the impacts on wetlands and floodplains. Monitoring should occur to determine if the changed flow release operations have the desired result and operations modified as necessary. It is expected that with the recommended change in flow releases, that the CBOPU water facilities would meet the intent and would be consistent with Executive Order 11988 and 11990. Clean Water Act: The perennial streams and adjacent wetlands in the analysis area outside of wilderness are designated as Class 2AB - Fisheries and Drinking Waters. Class 2AB waters are those surface waters known to support or have the potential to support populations of game fish and/or drinking water supplies. They are considered to be high quality waters, which support the beneficial uses of aquatic life, fisheries, drinking water, recreation, wildlife, agriculture and scenic value (WYDEQ, 2001). Intermittent streams in this area are classified by the State of Wyoming as Class 3B if no fisheries are thought to be present. These waters support beneficial uses of aquatic life other than fish, recreation, wildlife, agriculture and scenic value (WYDEQ, 2001). In Wyoming, the surface waters within wilderness areas and the mainstem of the North Platte River above Sage Creek (south of Saratoga) to the Colorado Border are designated as Class 1 Outstanding Waters. The State of Wyoming requires that the water quality existing at the time of designation will be maintained and protected (WYDEQ, 2001). In this analysis area, much of Cottonwood Creek lies within the Savage Run Wilderness. The Platte River Wilderness includes lower Douglas creek and the Encampment Wilderness includes the Encampment River downstream of Hog Park Creek. The State of Wyoming 303(d) list of “Waterbodies with Water Quality Impairments” (WYDEQ 20010) does not identify any impaired water bodies within the project area. Both Douglas Creek and Encampment River have been assessed by DEQ as fully supporting aquatic life uses as a cold water fishery and Class 1 Water, and so are currently meeting Clean Water Act standards (WYDEQ 2010).

Recent assessments by the State of Wyoming indicate that CBOPU water system operations currently meet water quality standards (WYDEQ 2010). The recommended changes in operations would have the effect of reducing erosion and so these facilities would continue to be in compliance with the Clean Water Act. Special Use Permit Clause Recommendations The following are recommendations concerning the special use permit clauses, additional special use permit clauses related to streamflows may also be necessary:

Stream Flow (R2-D101): For all the diversion / collection points, include this clause (with the 5 day high flow release language). Specify the minimum flows for all collection points with an existing minimum flow, and for Rob Roy and Hog Park Reservoir as specified in the 1982 easement, with the exception of Solomon Creek as discussed above. Add in a minimum flow for Standard Creek.

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Specified Flow Reservoir (R2-D102). Do not include this clause for Hog Park, but include Hog Park minimum flows in D102 as specified in the 1982 permit. This is because the minimum flow in Hog Park Creek (15 cfs) is higher than the natural low flows so that the transbasin water can be moved downstream.

Include R2-D105 for Lake Owen, as specified in the existing permit.

Operation and Maintenance Plan (R2-C102). Include descriptions of allowable flow releases as recommended in this report. Include a provision about low water years to allow operations to collect and divert more water during times of water shortage.

Either as part of the Operation and Maintenance Plan or elsewhere as appropriate, include a requirement to develop a lakeshore erosion control plan if determined necessary by the NFS.

Recommended Monitoring:

Monitor the flow release patterns from Rob Roy and Hog Park Reservoirs as described above to determine if the flow release patterns resemble natural hydrograph patterns.

Monitor bank erosion along Hog Park Creek to determine if revised operations have decreased bank erosion along the creek.

Cooperate with Wyoming Game and Fish to monitor conditions in Lake Owen that could affect viability of fisheries.

Continue monitoring compliance with all flow-related permit conditions

Monitor lakeshore erosion at Rob Roy and Hog Park reservoirs.

References Ferrick, Michael G., Gatto, L.W. and Grand, S. A., 2005. Soil freeze-thaw effects on bank

erosion and stability: Connecticut River field site, Norwich, Vermont. Hanover, New Hampshire, U.S. Army Cold Regions Research and Engineering Laboratory, ERDC/CREEL TN-05-7.

Gilliam, Elizabeth Ann, 2011. Assessing channel change and bank stability downstream of a

dam, Wyoming Master's Thesis. Colorado State University, Fort Collins, CO. Henderson, Marc B. 2006. changes in streambank erodibility and critical shear stress due to

surface subaerial processes (Master's Thesis). Virginia Polytechnic Institute and State University, Blacksburg, VA.

U.S. Forest Service, 2006. Watershed Specialist Report for Pirate's Gold Mining Claim. By

Carol Purchase, May 16, 2006. Medicine Bow-Routt National Forests Internal Report. On file at Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY.

U.S. Forest Service, 2011b. Cheyenne Board of Public Utilities Permit Renewal. Soil

Resources by Randy Teplar, September 28, 2011. Medicine Bow-Routt National Forests Internal Report. On file at Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY.

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U.S. Forest Service, 2012. Cheyenne Board of Public Utilities Operating Permit Renewal for

facilities occurring on NFS Lands Biological Evaluation. By Shawn Anderson. In progress. Medicine Bow-Routt National Forests Internal Report. On file at Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY

U.S. Forest Service, 2011a. Water Year 2003-10 Compliance Monitoring Summary– Favorable

Conditions of Waterflows. Medicine Bow-Routt National Forests Internal Report. On file at Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY. .

U.S. Forest Service, 1981. Final Environmental Impact Statement, Cheyenne Stage II Water

Diversion Proposal. Medicine Bow National Forest. 235 p. U.S. Forest Service, 2003. Medicine Bow National Forest Revised Land and Resource

Management Plan. Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY.

WYDEQ, 2010. Wyoming’s 2010 305(b) State Water Quality Assessment Report and 2010

303(d) List of Waters Requiring TMDLs. Wyoming Department of Environmental Quality. Cheyenne WY.

WYG&F, 2011. Letter of February 18, 2011 from John Emmerich, Deputy Director of WYG&F

to Mr. Cooksey (Deputy Forest Supervisor) in reference to CBOPU Permit Renewal. On file at Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY.

Young, Michael K., Haire, David, Bozed, Michael A. 1994. The effect and extent of railroad tie

drives in streams of southeastern Wyoming. Western Journal of Applied Forestry, Vol. 9, No. 4. October 1994.

Wesche, 1987. Habitat Restoration Plan for Douglas Creek. December 31, 1987. On file at

Medicine Bow-Routt National Forests and Thunder Basin National Grassland Supervisor's Office, Laramie, WY