Author Archives: Tom Cannon

State Water Board to Decide Fate of Shasta and Scott River Salmon and Steelhead – Part 3, the Shasta River

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On July 1, 2021, staff from the State Water Resources Control Board (State Board) held a public Zoom meeting to provide information and solicit input on potential actions that could be implemented to address low flows in the Scott River and Shasta River watersheds (Figure 1) during the ongoing drought.  The Scott and Shasta rivers are major salmon and steelhead producing tributaries of the Klamath River. The State Board’s July 1 workshop sought input and options prior to taking action.   

CSPA is providing comments through this three-part series.  Part 1 was the introduction with a description of the general problems and solutions.  Part 2 provided specific comments on the Scott River.  This is Part 3 on the Shasta River.

The Shasta River Problem

The Shasta River, like the Scott River, has a chronic streamflow problem that occurs in summer and fall of most years.  Only in very wet years, do flows sustain the needs of ranchers and fish for water.  In most dry years, nearly all the water in the watershed goes to agriculture, while  the lower river and most major tributaries run virtually dry (Parks Creek, Little Shasta River, Yreka Creek).  Salmon and steelhead survive during dry years only in the middle reaches of the mainstem Shasta River and in adjoining large springs fed by Mt. Shasta’s snow fields or leakage from Lake Shastina reservoir.

At the locations in the watershed that are watered by springs, large portions of the spring-fed flow are diverted for agriculture or other human use (e.g., bottled water, domestic use, cities, etc.).  Pasture irrigation, hay production, and stock watering are the major uses.  Much of the upper mainstem’s  water supply (both spring-fed and snowmelt) is stored in Lake Shastina and metered out over the summer for downstream use through a large canal and ditch irrigation system.  Big Springs, the dominant source of spring water to the middle and lower river, is diverted or pumped to irrigation ditch systems from several small diversion dams and multiple small distribution systems.

Most salmon and steelhead spawning and rearing occurs in the middle reaches of the river below Lake Shastina and in the reach near Big Springs, where spring-fed cold-water provides high quality spawning and rearing habitat.  The inputs of spring water in summer of drier years like 2021 are virtually gone by the time river water reaches Yreka (Figure 2) from the above mentioned extraction systems.  The base flow of approximately 150 cfs before the April 1 start of the irrigation season falls to 10-20 cfs or lower by summer.  Flow recovers after the irrigation season ends on October 1.  Most of the irrigation diversions in the mainstem Shasta River are located in the 10-20 miles downstream of the inflow from Big Springs, as is evident by at the streamflow gage near Montague (Figure 3).

Lower flows lead to high water temperatures in the lower river (>65ºF, Figure 4) that limit fish habitat, survival, and smolt production. Unlike the Scott River, dewatering and stranding are not a primary factor in the middle river’s spring-fed refuge.  Rather, the problem is high water temperature between Grenada and the Shasta River’s mouth at the Klamath River.  Historical water temperature records at the Yreka gage (Figure 5) indicate that the lower river is virtually uninhabitable in summer with water temperatures 20-25ºC because of low streamflows.  Historical data from the Montague gage indicate tolerable water temperatures (<20ºC) when streamflows are >50 cfs (Figure 6).   Such flows and water temperatures would at least provide minimum requirements for migrating adult fall run Chinook salmon in late summer.

Solution Option for the Shasta River

CDFW’s recommended minimum instream flows of 50 cfs (about a third of the base flow) is a reasonable measure that would maintain a modicum of over-summer rearing habitat in the spring-fed middle reach of the Shasta River and provide the opportunity for the late-summer salmon migration.   The major objective is to protect the many spring inputs in middle reach of the river, where most over-summer rearing of salmon and steelhead occurs, through summer season.  This can be accomplished by cutting back diversions and groundwater pumping in the Big Springs area, and by minimizing warm, polluted irrigation return water.

Figure 1. The Scott River and Shasta River Valleys in northern California west of Yreka, CA (Yreka is located in the Shasta River Valley). The Scott and Shasta Rivers flow north into the Klamath River, which runs west to the ocean. The Salmon River watershed is immediately west of the Scott River watershed. The upper Trinity River watershed is immediately to the south of the Scott River watershed.

Figure 2. Shasta River daily-average streamflows at Yreka gage 2018-2021 and historical average. Note very low flows in April 1 to October 1 irrigation season in 2020 and 2021. Base flow from large springs is approximately 150 cfs. Lower flows are from surface and groundwater extraction.

Figure 3. Streamflow in Shasta River at Montague gage 2019-2021. Note distinct reductions in April 1 to October 1 permitted irrigation season.

Figure 4. Water temperature of Shasta River at Grenada 2019-2021. Note water temperature increase at beginning of irrigation season on April 1 and decrease at end near October 1.

Figure 5. Streamflow and water temperature (min-max) of Shasta River near Yreka CA, March-October 2003.

Figure 6. Streamflow and water temperature (min-max) of Shasta River near Montague CA, May-July 2008.

State Water Board to Decide Fate of Shasta and Scott River Salmon and Steelhead – Part 2, the Scott River

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On July 1, 2021, staff from the State Water Resources Control Board (State Board) held a public Zoom meeting to provide information and solicit input on potential actions that could be implemented to address low flows in the Scott River and Shasta River watersheds (Figure 1) during the ongoing drought.  The Scott and Shasta rivers are major salmon and steelhead producing tributaries of the Klamath River. The State Board’s July 1 workshop sought input and options prior to taking action.   

 CSPA is providing comments through this three-part series.  Part 1 was the introduction, with a description of the general problems and solutions.  This is Part 2, with specific comments on the Scott River.  Part 3 will cover the Shasta River.

The Scott River Problem

The Scott River has a chronic low streamflow problem that occurs in the summer and fall of most years.  Only in very wet years, do ranchers and fish for the most part get the water they need.  In most years, nearly all the water in the watershed goes to agriculture, while the lower river and its tributaries run virtually dry.  Fish survive in the upper reaches of the river and in the lower tributaries that receive snowmelt and spring water from the adjacent Marble and Trinity mountains.  There are also spring-fed refugia in the middle sections of the river and In tributaries to the lower sections of the river.  But at many locations in the watershed, a large portion of the surface-water flow goes underground into near-surface aquifers, only to resurface as springs and be further diverted or extracted by wells, or go back underground.

The California Department of Fish and Wildlife is recommending summer minimum flows from 30-50 cfs at the lower end of the river to protect over-summering juvenile Chinook and Coho salmon, and steelhead.  These recommended flows represent roughly half of the available summer baseflow water supply in the Scott River.  Without a minimum flow requirement, almost the entire summer baseflow is  consumed by a carefully distributed water supply extraction system regulated by seniority-based surface water rights and overseen by the State Board or by minimally regulated groundwater pumping.  A large portion of the consumption occurs by means of minimally regulated shallow well pumping from the valley’s alluvial floodplain aquifer.  This supplies water for stock watering, pasture irrigation, or large scale sprinkler irrigation of hayfields.  The aquifer is recharged by surface flows and applied irrigation, and in places is augmented by beaver dam flooding.  The floodplain was once known as “beaver valley”.  However, much of such wetland floodplain habitat has been lost to channelization to enable irrigated agriculture.

There are many areas in the watershed that provide refugia for over-summering salmon and steelhead.  The extent of these refugia decreases over the summer as the surface water supply declines and springs cease flowing.  The loss of refuge habitat over the summer is greatest in drought years.  As the extent of refuge habitat declines, juvenile salmon and steelhead become more concentrated or succumb to “catastrophic stranding” where they die from refugia drying up or overheating.  Many refugia are on private lands.  Many are unidentified.  They need to be identified and surveyed to determine their characteristics and need for protection.

Drying rivers also pose problems for emigrating juvenile and immigrating adult salmon and steelhead in the fall and winter.  When fall rains and winter snow are lacking or late, juvenile fish are hindered or blocked from moving downstream to the Klamath River.  Adult fish cannot move upstream to spawning grounds in the valleys.

General Solution Options for the Scott River

Other than CDFW’s recommended minimum instream flows to save the fish (which would be successful), there are further options to help the fish.  One major option is to protect through the summer-fall season the many refuge areas that are present and functioning at the end of the spring snowmelt season. This can be accomplished in several ways:  (1) not allowing any diversion of surface or groundwater within or near the designated refuge; (2) pumping well water directly into the refugia; (3) diverting other surface waters into the refugia; and (4) protecting and enhancing refuge habitat (e.g., cattle fencing, riparian plantings, channel improvements).  The basic concept is to protect and enhance cold-water habitats of the refugia.  Each refuge will have its own prescription.  Some may benefit from introduced beaver colonies.  Note that some landowners working with CDFW and local stakeholder groups have accomplished some of these actions at varying scales of effort and with varying degrees of success.

Another solution option is a program to scale back seasonal agricultural water use based on the needs of fish and their habitat, as well as those of the landowners.  For example, a major problem for Scott River salmon is not being able to ascend into Scott Valley in the fall because of low streamflows.  Unlike the Shasta River Watershed, in which irrigation is disallowed after October 1, irrigation is allowed into December in the Scott watershed.  Scott Valley hay-crop irrigators in particular could cease irrigating a month or two earlier, foregoing late season cuttings.  This option was suggested by a landowner of a large ranch who was even willing to use his large-capacity wells to help water the river during the fall salmon migration.

Specific Recommended Solutions

The following recommendations offer large potential benefits with limited impacts and costs.

1.      Focus on the surface water irrigation diversions – all should cease in summer of dry years

Two large diversions with large canal distribution systems make up the bulk of the surface water diversions in Scott Valley, at least in wetter years or spring of drier years.  If these have not as yet cut back diversions as in most dry years, their diversions should cease.  The largest diversion, Young’s Dam, is a relatively large concrete structure with a fish ladder (Figure 2).  In summer of dry years, it usually does not divert, but does back up water in the river channel, causing significant rises in water temperature.  More flow would minimize such heating.  More flow is necessary to provide upstream passage of adult salmon in late summer and fall through the dam’s fish ladder, even when the dam is not diverting water.

The second largest surface diversion is Farmers Ditch, which diverts directly from the Scott River channel (Figure 3).  It too usually does not divert in summer of dry years, due to lack of surface flow.  Prior to ceasing its diversions, it contributes to drying up the river in the downstream tailings reach.

There are many small diversions1 in the middle and upper valley from reaches of the river and lower tributaries that retain flows in the summer.  Locally, they divert significant portions of the available streamflow.  Some are crudely designed and operated, and are unregulated (Figure 4).  All surface diversions should cease operating, since most are from spring-fed stream reaches supporting rearing salmon and steelhead.  In many cases, such diversions contribute to the dewatering of downstream reaches.  One such example is lower Shackleford Creek, where multiple small diversions in flowing spring-fed sections in the several miles upstream contribute to the drying up of the creek near its mouth on the Scott River (Figure 5).

2.      Middle and lower reaches of Scott River affected by groundwater pumping – all well pumping from locations contributing to dewatering of the main channel of the Scott River or lower tributaries should cease pumping.

Most free-flowing reaches of the middle and lower Scott River and its lower tributaries are over-summering juvenile salmon and steelhead refugia.  Even warm low flows provide some cooler hyporheic flow to sustain young salmon and trout in microhabitat areas of the stream channel (Figure 6; also see videos referenced at the end of this post).  Such locations cannot support high population densities for long and thus could use added flow to sustain them.

3.      Refugia in middle and lower reaches of Scott River and lower tributaries affected by groundwater pumping could be supported by pumping cold groundwater into stream channels to help sustain refuge habitat.

In reaches where groundwater pumping is no longer needed, idle wells can pump cold groundwater directly into stream channels to sustain specific refugia or to provide added flow for fish migrations.  Many ponds situated within the Valley’s water table have cold water that could be drained or pumped to refuge areas.  The tailings reach in the upper end of the Valley has many such ponds.

Summary and Conclusions

All surface diversions from free-flowing reaches of the Scott River should cease in summer-fall of 2021.  All such reaches are fed by snowmelt or springs, and are most likely refugia for over-summer rearing salmon and steelhead.  All well pumping near the river and lower tributaries that may affect springs or hyporheic flow in refugia should be cut back to help sustain the refugia.  All refugia should be identified and classified to value and need.  Where feasible, wells or surface waters can supply supplemental water to sustain refugia.  All refugia should be mapped, surveyed, and characterized for need; high value  options should be identified and implemented.  All irrigation in the Scott Valley (not including stock watering) should cease by October 1, as is already done in the Shasta Valley.  Cutbacks of well pumping for Scott Valley irrigation should commence on a graded scale on August 1 and September 1.

Figure 1. The Scott River and Shasta River Valleys in northern California west of Yreka, CA (Yreka is located in the Shasta River Valley). The Scott and Shasta Rivers flow north into the Klamath River, which runs west to the ocean. The Salmon River watershed is immediately west of the Scott River watershed. The upper Trinity River watershed is immediately to the south of the Scott River watershed.

Figure 3. Farmers Ditch diversion located in upper middle valley on Scott River.

Figure 2. Young’s Dam and diversion located on the Scott River in mid-Valley.

Figure 4. An unnamed small diversion located in spring-fed reach of Scott River below tailings reach. Both the river and diversion ditch contained large numbers of juvenile coho salmon.

Figure 5. The mouth of Shackleford Creek on Scott River in late summer.

Figure 6. Reach of the lower Scott River upstream of Fort Jones near Eller Bridge, nearly dewatered by groundwater pumping and lowering of the groundwater table. Despite lack of flow, the reach retains some over-summering refuge pools sustained by groundwater and hyporheic flow. Eventually, these areas become too warm, and many thousands of juvenile salmon and steelhead die. Such areas would benefit from a cessation of irrigation with water sourced from adjacent wells. Idle wells could be employed to add cold water to sustain the refugia.

Available Videos of Scott River Refugia

 

 

 

  1. There are approximately 800 water right holders in the Scott River watershed. ↩

Low Delta Outflow Not Keeping Bay Salt Water out of the Delta

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Low Delta outflows at the beginning of summer 2021 (Figure 1) are not adequately keeping brackish Bay water out of the west Delta (Figures 2-4). One reason salt is intruding is the high “spring” tides (Figure 5). Another factor is the State Water Board’s Order granting a Temporary Urgency Change Petition (TUCP) to the Department of Water Resources (DWR) and the Bureau of Reclamation. The Order allowed the installation of the False River Barrier in early June that helps force freshwater Delta inflow from the Sacramento and San Joaquin rivers to the south Delta pumping plants. It also allows lower summer Delta outflows and weaker salinity standards in this critical water year. The normal critical summer outflow criteria is a monthly average 4000 cfs. The outflow requirement was reduced to 3000 cfs. The normal salinity standards for a critical dry year are 14-day-average 2.78 EC at Emmaton and 2.2 EC at Jersey Point. The Emmaton compliance point was moved upstream to Three Mile Slough. Even at the upstream compliance point, the criteria limit has been exceeded (see Figure 2).

In the 2014 and 2015 drought years, Delta smelt almost disappeared entirely when the State Water Board granted a series of TUCPs that moved the salinity compliance points in the Delta upstream. Delta smelt have in no sense recovered.1 In the 2021 TUCP, DWR and Reclamation were unable to show the recent distribution of Delta smelt in the Delta: there are too few Delta smelt left to meaningfully count.

Figure 1. Daily average Delta outflow during June 2021.


Figure 2. Salinity (EC, mean daily) at Three Mile Slough near Rio Vista during June 2021.

Figure 3. Salinity (EC) and water temperature (C) in the lower Sacramento River channel near Emmaton during June 2021. Note spring/neap tide effects with warmer, fresher water draining the Delta on neap tides.

Figure 4. Salinity (EC) in the lower San Joaquin River channel near Jersey Point in the west Delta during June 2021.

Figure 5. River stage in the lower Sacramento River channel near Rio Vista in the west Delta during June 2021.

  1. See for example https://calsport.org/fisheriesblog/?p=2709. This blog (see the “Smelt” tab to the right) has chronicled the catastrophic decline of Delta smelt since 2015. ↩

State Water Board to Decide Fate of Shasta and Scott River Salmon and Steelhead

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On July 1, 2021, staff from the State Water Resources Control Board (State Board) held a public Zoom meeting to provide information and solicit input on potential actions that could be implemented to address low flows in the Scott River and Shasta River watersheds (Figure 1) during the ongoing drought.  The Scott and Shasta rivers are major salmon and steelhead producing tributaries of the Klamath River.

Low flows in the Scott and Shasta have led to the recurring mortality of salmon and steelhead due to high water temperatures, stranding, or hindered migration.  The recurrence, duration and intensity of mortality events now threatens the extinction of salmon and steelhead in these rivers. 

Low flows in both watersheds are caused by surface diversions and groundwater extraction by local agriculture.  Although low flows are often attributed to drought and climate change, they have become a regular occurrence even in wetter years.  Drought and climate change intensify and increase the frequency of low flow conditions that have become the norm each summer and fall. 

The State Board under the governor’s drought emergency declaration could limit water use to help save the fish.  This would come at substantial cost to local agriculture and communities.  The State Board July 1 workshop sought input and options prior to taking action.

The California Department of Fish and Wildlife is recommending summer minimum flows near 50 cfs to protect over-summering juvenile Chinook and Coho salmon, and steelhead.  Such flows represent roughly half of the available water supply in both rivers.  Absent action by the State Board, this water would be nearly completely consumed by a carefully distributed water supply extraction system regulated by seniority-based state water rights overseen by the State Board.

In this three-part report, CSPA provides a general strategy plus watershed-specific recommendations to help address the issues and save the fish.  In this introduction, we address the general problems and solution strategies.  We will follow up with by two watershed-specific parts, one on the Scott and one on the Shasta.

General Problem

The low-flow problem in the Scott and Shasta watersheds occurs in most years.  In exceptional high flow, high snowmelt years, ranchers and fish for the most part get the water they need.  So in most years, nearly all the water goes to agriculture ,and the lower rivers and their tributaries go virtually dry.  Fish survive in the upper river and tributaries, and in middle portions of the mainstem rivers that convey water to the more downstream users.  Overall, large portions of the flow go underground into near-surface aquifers, only to resurface and be further diverted or extracted by wells.

There are many areas in both watersheds that provide refuges for over-summering salmon and steelhead.  The extent of these refuges decreases over the summer as the surface water supply declines and springs cease flowing.  The loss of refuge habitat over the summer is greatest in drought years.  As the extent of refuge habitat declines, juvenile salmon and steelhead become more concentrated.  Many succumb to “catastrophic stranding,” where they die because refuges dry up or get too hot.

Drying rivers also pose problems for emigrating juvenile and immigrating adult salmon and steelhead in the fall and winter.  When fall rains and winter snow are lacking or late, juvenile fish are hindered or blocked from moving downstream to the Klamath River.  Adult fish cannot move upstream to spawning grounds in the valleys.

General Solution

The general solution is to focus on maintaining summer refuges and providing fall and early winter flows.  Refuges can be maintained on a general or individual basis by protecting natural surface and spring flows or providing supplemental flows where feasible.  Each watershed has specific options for sustaining or supplementing streamflows.

Each watershed has about 100 cfs of base streamflow in summer, maintained by permanent springs or higher-elevation snowmelt.  Maintaining a 50 cfs flow as recommended by CDFW is a matter of cutting surface diversions and groundwater extractions.  To minimize restrictions on water users, flows can be supplemented from various limited surface storage sources or from groundwater aquifers.  Both these options can be accomplished to a great extent in the short term.

Since opportunities to save fish this year exist, quick action is necessary.  An intensive survey-monitoring program is needed to (1) best allocate available resources, (2) effectively apply necessary restrictions, and (3) evaluate the effectiveness of actions taken.

In the next two parts, we address watershed-specific problems and solutions for the Scott River and Shasta River watersheds. 

Figure 1. The Scott River and Shasta River valleys in northern California. Yreka, CA is located near the northwest corner of the Shasta River valley. The Scott River valley is west and somewhat south of Yreka. The Scott and Shasta rivers generally flow north into the Klamath River, which generally runs west to the ocean. The Salmon River watershed is immediately west of the Scott River watershed. The upper Trinity River watershed is immediately south of the Scott River watershed.

Reclamation Begins Summer Shasta Operations that Sacrifice Endangered Winter-Run Chinook Salmon to Power Production and Irrigation Deliveries

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Reclamation has begun its planned summer operation for winter-run salmon in this critically-dry summer of 2021. After delivering a lot of warm surface water from Shasta Reservoir to its downstream contractors this spring,1 Reclamation has now begun dipping into Shasta’s cold-water pool (Figures 1 and 2). Reclamation’s summer operation will encourage the holding salmon to spawn and, for a time, ensure the eggs can survive in the primary ten-mile spawning reach downstream to the mouth of Clear Creek (CCR). Reclamation’s plan would subsequently raise water temperatures later in summer, after peak spawning and embryo development have occurred.

In first five days (June 17-22) of the new operation, Reclamation met its target temperature. It has released about 8000 cfs of 53ºF water from Keswick Dam to the Sacramento River near Redding (Figure 3). It achieved the target by blending hydropower-peaking flows from Shasta and Whiskeytown dams in Keswick Reservoir, and then releasing the blended water to the Sacramento River below Keswick Dam. During this time, Reclamation released an average of 6500 cfs from Shasta Dam at 50-51ºF, and an average of 1200 cfs at 53ºF through the Spring Creek Powerhouse (SPP) from Whiskeytown, into Keswick Reservoir.

This operation is not sustainable over the summer. It uses more of the cold-water-pool volume than is necessary to maintain temperature control. It sacrifices the cold-water pool in order to continue power peaking and to maintain relatively high downstream irrigation deliveries. Considering all of the factors pushing Keswick release temperatures higher over the summer, there will not be enough cold water by the end of the summer to protect salmon.

High Shasta Dam releases in the afternoon and evening to meet peak power demands pull more water from the warmer surface waters of the reservoir (Figures 4-6). This then requires blending with cold-water releases to keep Keswick water cooler. A similar situation occurs with the Whiskeytown releases (Figure 7-8). In addition, water in Whiskeytown becomes progressively warmer over the summer and requires an ever-increasing amount of Shasta’s cold-water pool to cool that water. Atmospheric heating combines with heating of water from Shasta during power-peaking operations to further affect Keswick Reservoir’s water temperatures (Figures 9 and 10).

Reclamation’s current high demands on Shasta’s cold-water pool will thus require reverting in late summer to warmer water releases. This will lower the survival of late summer spawners and their eggs. It will also leave little cold water for fall-run salmon in October and November. Reclamation is willing to accept these trade-offs to make relatively high power and irrigation deliveries.

To reduce the loss of winter-run (and fall-run) salmon this summer, CSPA and two other organizations submitted an alternative Temperature Management Plan (CSPA TMP) to the State Water Board on May 23, 2021. The CSPA TMP would provide better summer water temperatures and salmon egg survival. The CSPA TMP, comprised of a transmittal letter, descriptive elements and spreadsheet, proposes a release of just 5000 cfs of 52-53ºF water from Shasta Dam’s gates and minimal warmer water inputs from Whiskeytown/Trinity. The CSPA TMP proposes a 5000 cfs release of 53-54ºF water from Keswick, with less daily peaking power production to limit withdrawals of warm water from the surface of Shasta reservoir.

The CSPA TMP would minimize impacts to the salmon and save approximately 200,000 acre-feet of Shasta storage. It would also save 200,000 acre-feet of Trinity storage. It would greatly reduce power production from five system powerhouses, though power generation capacity would still be available for periods of extreme power demand.

Above all, the CSPA TMP would reduce water supply deliveries in the Sacramento Valley and eliminate water transfers from Shasta in the summer and fall. Reclamation is willing to sacrifice a substantial portion of the Sacramento River’s salmon in order to prioritize agricultural water deliveries. The CSPA TMP prioritizes a system operation that will reasonably protect salmon, and allocates water supply based on the water that is available within the constraints of that operation.

Figure 1. Shasta Dam infrastructure and operations, and cold-water pool conditions, during the June 17-22 period. Note water release from PRG gates, drawing from the layer of water less than 48ºF, and release from middle gates of water that is 70ºF or warmer. The combined flow release from the Temperature Control Device was 6000-7000 cfs of 51-52ºF water.

Figure 2. Water temperatures (ºF) recorded at Sacramento River gages from Shasta Dam (SHD, RM 310) downstream to Red Bluff (RDB, RM 240) 5/1-6/16, 2021. Keswick Dam (KWK, RM 300) is the release point from the Shasta Dam complex to the Sacramento River. Spawning area is ten miles downstream of Keswick to mouth of Clear Creek (CCR). Red arrow points out yellow highlight of recently changed operation to benefit salmon spawning.

Figure 3. Water temperatures (daily average. ºF) from Shasta Dam release (SHD) and from Keswick Dam (KWK, RM 300) downstream through primary winter-run spawning reach to gage located just upstream from mouth of Clear Clear Creek (CCR, RM 290). Note: the difference between SHD and KWK release temperatures are due to inputs to Keswick Reservoir from Whiskeytown from Whiskeytown Reservoir through the Spring Creek Powerhouse (SPP) and to internal heating and mixing in Keswick Reservoir. The compliance control point gage is SAC, located at the midpoint of the ten-mile spawning reach. The compliance point target was 55ºF during the period.

Figure 4. Water temperature (ºF) at gage SHD immediately downstream of Shasta Dam, June 17-22.

Figure 5. Shasta Reservoir hourly outflow (cfs), June 17-22.

Figure 6. Water temperature (ºF) at gage SHD immediately downstream of Shasta Dam, June 17-22.

Figure 7. Hourly measued water release (cfs) from Whiskeytown.

Figure 8. Water temperature (ºF) at gage SPP immediately downstream of Spring Creek Powerhouse June17-22.

Figure 9. Keswick Reservoir hourly outflow (cfs), June17-22.

Figure 10. Water temperature (ºF) at gage KWK immediately downstream of Keswick Dam, June17-22.