Secret Ravine Adaptive Management Plan

This version of the Secret Ravine AMP incorporates comments received afterdistribution of the draft to stakeholders and technical advisors. The revision benefitsgreatly from those comments and especially from review by Tom Cannon, LoriWebber, and Kelly Finn.

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Table of Contents

1 Introduction
2 Background
3 Stakeholders

3.1 Stakeholder Interests

4 Conceptual Model

4.1 Landscape Level Conceptual Model
Figure 1 Landscape Level Conceptual Model of Chinook Salmon
4.1.1. Chinook Salmon Life History
4.1.2 Steelhead Trout Life History
4.1.3 Current Habitat Conditions for Salmonids

4.2 Summary of Existing Conditions Report

4.2.1 Geomorphology
Figure 2 Watershed Map (DEM)
4.2.2 Vegetation
4.2.3 Stream Habitat
4.2.4 Conclusions of existing conditions report
4.2.5 Recommendations of Existing Conditions Report

4.3 Stressors and Impacts

Table 1 Summary of Stressors and impacts for salmon and steelhead in Dry Creek

4.4 Hypotheses Concerning Restoration and Management

Table 2 Summary of Hypotheses
4.4.1 Adult migration
4.4.2 Spawning
4.4.3 Incubation and emergence
4.4.4 Juvenile rearing
4.4.5 Juvenile migration

4.5 Suggested Actions and Adaptive Management Studies

Table 3 Summary of Suggested Remedial Actions for Stressors
Table 4 Summary of Adaptive Management Studies
4.5.1 Education-Actions and Adaptive Management Studies 4.5.2 Coordinated Management-Actions and Adaptive Management Studies
4.5.3 Restoration-Actions and Adaptive Management Studies
4.5.4 Additional Adaptive Management Studies

5 Implementation

Table 5

6 Studies pertaining to Tributaries of Dry Creek
LITERATURE CITED
APPENDIX_A Executive Summary of Secret Ravine Existing Conditions Report
APPENDIX B Aerial Photo Atlas of Natural Vegetation
APPENDIX C Restoration Plans
APPENDIX D Related Memos

 


























1 INTRODUCTION

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The goal of the Secret Ravine Adaptive Management Plan (AMP) is to define a process to restore the approximately 10 miles of instream and riparian habitats between Rock Springs Road and the confluence with Miners Ravine (See Map 1) to sustain native terrestrial and aquatic species of Dry Creek Watershed, and to help meet the Central Valley Project Improvement Act (CVPIA) goal to double natural production of Chinook salmon and steelhead.The importance of small tributaries such as Secret Ravine to salmonid restoration is explained by McEwan, (2001):

Due to highly variable natural conditions in the Central Valley, inter- population dynamics may be essential to the persistence of rainbow trout populations in the smaller stream systems. Historically, larger source populations occupying more stable habitats (for example, upper Sacramento, Feather, Yuba, and American rivers) provided a source for recolonization and gene flow to the smaller, less-persistent sink populations occupying more hydrologically unstable stream systems. Conversely, the long-term persistence of the source populations may be affected by the diversity and viability of the smaller subpopulations. The precipitous decline of Central Valley steelhead has been alarming not only from the standpoint of reduction in absolute numbers, but also in the elimination of the populations that occupied the many tributaries. A reduction in the large river source populations may also explain the precipitous decline of steelhead in smaller streams, in spite of the large amount of quality habitat that still exists in these systems. Thus, restoration that focuses only on increasing absolute numbers and ignores the need to increase population diversity may be inadequate.

 Although this plan is focused on restoring salmonids and their habitat, it recognizes diverse interests of a variety of stakeholders. Remedial actions that satisfy multiple interests and attempt to avoid conflict with other interests receive highest priority. To a large extent salmonids are indicators of watershed health, so enhancing their use of the watershed enhances all natural values of the watershed.

 Dry Creek Conservancy has documented a self-sustaining run of Fall Run Chinook Salmon with Fall surveys during the four seasons of 1998 to 2001. The California Department of Fish and Game (CDFG) has records (memos to file, 1964 to 1992) showing salmonid populations in the 1960's, and there is plentiful anecdotal evidence showing salmonid populations for more than a century (personal communication from watershed residents). A recent study by the Native Anadromous Fish and Watershed Branch of CDFG (Titus, 2001, Appendix D) concluded that:

…the upper Dry Creek drainage continues to support production of steelhead, as recognized historically but presumably at lower levels due to habitat impacts from urban development. The upper creek areas appear to be especially important for spawning and rearing, given the stream gradient and temperature condition there. Any actions which protect or improve access to and the quality of these areas will benefit steelhead production in the system.

The lower creek areas, including mainstem Dry Creek, need to be protected and improved for Chinook salmon spawning, juvenile rearing and emigration and for seasonal rearing and migration of steelhead. The most conspicuous needs are to identify, control and prevent sources of sediment pollution, and to discourage land-use and waterway practices that favor production of introduced warmwater fishes, especially as related to pond development and stocking of these species within the system.

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The remedial actions described in the AMP are those that Dry Creek Conservancy (DCC) and the Dry Creek Coordinated Resource Management and Planning Group (CRMP) believe have a high probability of increasing natural salmonid production and satisfying a wide array of stakeholder interests. It is unknown whether all important environmental factors limiting fish production have been identified and whether the identified problems can be remedied. The AMP will be implemented with the goal of resolving the uncertainty regarding restoration actions and of improving the effectiveness of future restoration actions.

 

Figure 1 Study Area Map

 

 The AMP is not intended to restore the watershed to pre-Columbian condition. The watershed has been permanently altered by human activities such as mining, agriculture, and urban development. Stakeholders must now work with the existing conditions to achieve the best attainable condition.

 This plan is based on information in four reports prepared by resource consultants (Stacey Li, Wayne Fields, Mitchell Swanson, and Robert Holland) that comprise an existing conditions report (ECR), as well as other studies and observations. A set of stressors (environmental factors that constrain ecosystem health) specific to Secret Ravine is derived from this information. Hypotheses are made to precisely define issues so experiments can be designed to test them. As new data are collected, the restoration actions and hypotheses will be periodically refined.

Success will be dependent on the continued existence of a stakeholder group such as the Dry Creek CRMP and DCC, and landowners willing to work together with the CRMP to implement AMP actions.

The AMP relates to several other planning processes involving Secret Ravine. First, a Prop 204 grant awarded Placer County includes developing a watershed management plan for the Dry Creek Watershed. The Secret Ravine AMP will provide information to the larger watershed plan. Second, a Calfed Watershed Group grant was awarded to City of Roseville to develop a stream channel and riparian management plan for streams within the city. The Secret Ravine AMP will contribute to management of the portion of Secret Ravine that is within City of Roseville. In addition, DCC has been granted Calfed funds to develop GIS mapping, ongoing stewardship, and other projects.

 

2 BACKGROUND

Dry Creek Conservancy was formed as a nonprofit, charitable corporation in 1996 to preserve and restore the resources of the Dry Creek Watershed. The board of directors is comprised of interested citizens. DCC organizes activities for education, planning and management, restoration, and monitoring.

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The Dry Creek CRMP was formed in 1996 by Dry Creek Conservancy, Placer County Resource Conservation District, and the National Park Service Rivers, Trails, and Conservation Assistance Program. The CRMP is a collection of stakeholders including agencies, landowners, and other interested parties. Participants may sign a voluntary memorandum of understanding "…to work together toward common goals…to improve resource management and minimize conflict between landowners, land users, recreational users, governmental agencies and conservation groups." The AMP will be implemented with CRMP support. Stakeholders to the AMP will be considered CRMP participants.  

A summary of the goals of the Dry Creek CRMP follows: 

1. Protect and restore the watershed to enhance fish, wildlife, and other natural resources.

2. Recognize the rights and cultural heritage of landowners in the watershed.

3. Promote recreational use of the watershed consistent with protection of private property and natural and cultural resources.

4. Promote cooperative partnerships among federal, state and local agencies, landowners and other stakeholders.

5. Promote the education of individuals, organizations and agencies on the function and management of a healthy watershed.

6. Enhance the general public's understanding and support.

7. Promote individual projects along the creeks to protect and enhance the anadromous fishery and riparian corridors.

8. Promote optimal passage of stormwater to:

o Minimize future flood losses

o Protect streambanks from accelerated erosion

o Protect riparian vegetation

o Properly manage stream environment flora and fauna

o Provide for recreation and open space needs where possible

o Discourage filling and building in the floodplain

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Implementation of this AMP will contribute directly to goals 1, 4, 5, 6, and 7. Understanding gained from working with the AMP will improve the CRMP's ability to meet goals 2, 3, and 8.   Chinook Salmon and Steelhead have a charismatic quality that helps people understand and identify with the effort to protect watershed resources. Their threatened status on the West Coast draws resources to restoration efforts. The California Department of Fish and Game has supported DCC efforts to improve habitat for salmonids for over four years. John Nelson, Region II anadromous fisheries biologist, has consistently been an advisor to and supporter of DCC and the Dry Creek CRMP. Also, CALFED and CVPIA funding is strategically directed toward restoring salmon and steelhead populations in the Central Valley.

Funding for developing this plan comes from the Anadromous Fish Restoration Program (AFRP), a program of the Central Valley Project Improvement Act (CVPIA). TheCVPIA was enacted to restore resources lost as a result of dams and other projects thatare part of California's history of developing water supply for agriculture and cities. TheAFRP is a component of the CVPIA and is administered by the U. S. Fish and WildlifeService. Additional funds for salmonid related projects on Secret Ravine have comefrom National Fish and Wildlife Foundation, California Department of Fish and Game,and AKT and Actium Development companies.

3 STAKEHOLDERS

About one half of the creek side property is or will be held by the county, cities, and Sierra College. Homeowners and small landowners comprise most remaining land. Categories of stakeholders include:

 

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3.1 Stakeholder Interests

Dry Creek Conservancy has met with homeowner associations, municipal advisory councils, Sierra College, Sutter Hospital, city departments, agency representatives, individuals and others to discuss their interests. Stakeholders also participate regularly in the Dry Creek CRMP. Some of the interests stakeholders express are:

As entities pursue their interests, they often cause some of the stressors identified inthe watershed. This plan will strive to find solutions that satisfy mutual interests.

4 CONCEPTUAL MODEL

4.1 Landscape Level Conceptual Model

Figure 2

A graphic representation of the salmon life cycle. A summary of the life history follows.

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4.1.1. Chinook Salmon Life History

Chinook, especially fall run, have a capability of using intermittent streams such as the Dry Creek system by migrating, spawning, incubating, and emerging all during the winter rainy season. Adult fall-run Chinook salmon migrate upstream into freshwater from July through December and spawn from early October through late December. Migration activity increases with seasonal rainstorms. If high flows don't occur there may be little spawning or fry or smolt production from the stream that year. So Chinook depend on several years of spawners from each spawn returning or from strays from other rivers to repopulate intermittent streams that have lost their populations during extended droughts. Fall-run Chinook salmon spawn in the low gradient portions of Central Valley streams such as the main stem Sacramento River, Mill Creek, Deer Creek, Feather River, Yuba River, Bear River, American River, Cosumnes River, Mokelumne River, Stanislaus River, Tuolumne River and Merced River and their tributaries. Peak spawning occurs in October and November, although the timing of runs varies from stream to stream. Embryo incubation occurs from October through March, and juvenile rearing and smolt emigration occurs from January through June. Timing of emigration varies with the amount of rainfall for the year. The majority of young fall-run Chinook salmon emigrate to the ocean during the first few months following fry emergence from the spawning gravels.

Chinook salmon spawning typically occurs in swift, relatively shallow riffles, along edges of fast runs where there is an abundance of loose gravel, or in tailouts of pools where depth declines, water velocity increases and 1-4 inch gravels settle out, and where water flows down into gravel to oxygenate the eggs. Chinook salmon require clean and loose gravel that will remain stable during embryo incubation, while the larvae reside in the gravel, and when they emergence from the gravel. Sufficient water must percolate through the gravel to supply oxygen and remove metabolic wastes from the developing embryos. Eggs and fry are extremely sensitive to sand and suspended sediments that may block flow and interrupt the oxygen supply or the ability of fry to eventually escape from the gravel beds.

The female digs a spawning redd in the gravels and deposits her eggs in several egg pockets. The eggs are fertilized by the male and buried in the gravel by the female. The adults die within a few days or weeks after spawning. An average female Chinook salmon produces 3,000-6,000 eggs depending on the size and race of fish.

Embryos usually hatch in 40 to 60 days. Alevins usually remain in the gravel for an additional four to six weeks until the yolk sac is completely absorbed; then they emerge from the gravel as fry. Fall-run Chinook salmon fry can begin emigrating to the estuary soon after emerging from the gravel and emigrate January through June.

Chinook salmon embryo, alevin, and fry development is stream temperature dependent. The embryo life stage is more sensitive to water temperature stress than any other Chinook salmon life stage. The fry (30-50 mm) typically seek out low velocity stream margins and backwaters attempt to hold position in the water column and feed mostly on drifting aquatic invertebrates in low velocity water or in eddies. Many fry migrate from Secret Ravine, but some remain. The proportion that migrate as fry may be a function of available habitat and total numbers using that habitat as well as river and habitat conditions at the time. As young grow from Fry to fingerlings they move into stations with higher stream velocities that carry larger food. Fry, fingerling, and smolts that migrate from Secret Ravine may rear from weeks to months in the lower watershed, Sacramento River, or the Bay-Delta before migrating to the ocean where they may spend one to three years feeding before returning to spawn. Chinook salmon generally mature at three to four years of age.

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The abundance of Chinook salmon has declined in the Sacramento River from as many as one million spawners prior to 1915 (Reynolds et al. 1990), to an average of 176,000 between 1967 and 1991 (Mills and Fisher 1994). There are no accurate records of the run size in Secret Ravine or whether fall run were the only historic race in the stream.  

4.1.2 Steelhead Trout Life History

Steelhead trout are anadromous rainbow trout that emigrate to sea and later return to inland waters as adults to spawn. California steelhead total age rarely exceeds six years. Unlike Pacific salmon, not all steelhead die after spawning.

Steelhead spawn in winter or early spring after salmon have spawned. They often require high water to provide access to upper watershed spawning and rearing areas. Because steelhead young remain at least a year in freshwater, they usually spawn at higher elevations where water temperatures are cooler in late spring and summer. Access to cool summer water temperature is perhaps the single most important limiting factor for steelhead in Central Valley streams.

Steelhead prefer to spawn in clean, loose gravel, and swift, shallow water. The female steelhead digs six to seven egg pockets in each redd. The male steelhead fertilizes the eggs as they are deposited. The female then covers the eggs with gravel. A female steelhead from the American River produces an average of 3,500 eggs.

Steelhead tend to prefer shallower stream depths and smaller gravel but the same water velocities for spawning as the Chinook salmon. Steelhead are even less tolerant of fine sediment in the gravel than Chinook salmon, probably because the eggs are smaller and the oxygen requirements for developing embryos are higher. Steelhead generally spawn in different stream areas when they spawn in the same stream stretch as salmon, thus special attention has to be focused on both spawning habitat types in streams.

The rate of steelhead embryo development is stream temperature dependent, and consistency of stream temperature is also important. Embryos usually hatch in about 30 days. Fry usually emerge from the gravel about four to six weeks after hatching. Juvenile steelhead usually remain in freshwater for at least one year before emigrating to the ocean. Unless there are adequate water temperatures, high rearing mortality will occur. The lethal temperature for young steelhead is about 77F. Temperatures of 65F can be stressful depending on other factors such as food. Optimal temperatures for steelhead are 50-60 F.

Historically, steelhead were distributed throughout the tributaries and headwaters of the Sacramento prior to closure of rivers by dams, water manipulation, and watershed perturbations of the 19th and 20th centuries. The Central Valley Steelhead ESU was listed as threatened by the National Marine Fisheries Service on March 19, 1998 (63 FR 13347).  

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4.1.3 Current Habitat Conditions for Salmonids

Diversions, elevated stream temperatures, pollution, channelization and the Delta pumps are important factors in the decline of anadromous fishes in the mainstem Sacramento River. Levee stabilization projects remove riparian vegetation and destroy habitat through replacement of natural bank with large rock riprap. Extensive removal of large tracts of riparian forest results in reduced shading, reduction of instream habitat, and reduction of organic inputs. Central Valley riparian forests have been reduced to about one percent of the pre-gold rush acreage (Abell 1989 cited in McEwan and Jackson 1994).

4.2 Summary of Existing Conditions Report

The team approach was used to get a broad knowledge of the conditions. A multidisciplinary team consisting of Stacy Li, fisheries biologist, Wayne Fields, aquatic entomologist, Robert Holland, geobotanist, and Mitchell Swanson, geomorphologist worked on their respective aspects of the stream corridor.

4.2.1 Geomorphology

Hydrologic and Physiographic

Setting Secret Ravine is a perennially flowing stream that drains a 19.7 square mile basin within the Sierra Nevada foothills of western Placer County (Figure 1). Secret Ravine flows 10.5 miles from its headwaters in the Newcastle area (elevation 1285 feet) to its confluence with Miners Ravine Creek (elevation 165 feet) near Eureka Road in Roseville. Streamflow is augmented by an unknown volume of tailwater delivered by Placer County Water Agency's irrigation releases. We observed flows in the early fall between 0.5 and 2-3 cfs. No continuous recording stream gage exists on Secret Ravine, but there is a flood activated warning gage operated by Roseville located in Rocklin near Sierra College Boulevard.

The Secret Ravine drainage basin experiences a Mediterranean climate with warm dry conditions between April and October and wet and mild weather between November and March. Average rainfall is 25.0 inches per year with most occurring during the peak rain months of December through February. The basin is underlain by granitic rocks of Mesozoic age and is capped unconformably by volcanic and volcaniclastic rocks of the Miocene Merhten Formation (occurring primarily in the lower watershed) and by Pleistocene alluvial fan and fluvial deposits of the Turlock Lake and Riverbank Formations. In the watershed hillslopes, Mehrten volcanic bedrock units develop shallow soils that generally have very high runoff rates. The granitic soils vary from shallow veneer over bedrock to deeper soils over zones of deeply weathered and decomposed granite.

 

Fig 3

Digital Elevation Model (DEM) Watershed Map for Secret Ravine

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Secret Ravine flows within a narrow valley underlain by recent alluvial deposits. The valley width expands in places to over 1,000 feet likely as the result of geologic controls. The central alluvial valley is bound by hills that are composed of granitic rock in the upper watershed and volcanic cap rock in the lower watershed. Soils in the alluvial valley vary from coarse-grained and highly permeable decomposed granite units (resulting from waste products of placer mining and sluicing and runoff from quarry spoils) to dense organic soils typical of perennial wetlands. The valley floor vegetation types include valley oak grasslands, riparian forest, and patches of seasonal wetlands.

Channel Morphology Secret Ravine flows within a channel that is entrenched within the alluvial valley floor. This appears to be the result of: 1) historical filling of the alluvial valleys with re- deposited placer and quarry mining spoils; and 2) possible channelization for subsequent agricultural use and urban development. As a result, Secret Ravine is not close to the ideal three stage channel. The channel is typically 6 to 8 feet deep (in some reaches over 12 feet deep), flat bottomed and rectangular in shape and anywhere from 10 to 25 feet wide. A large range of flows is contained within the channel which leads to further lateral and vertical erosion. In addition, the ability of the channel to dispose of excess sediment by carrying it onto the floodplain in overbank flows is diminished. Moreover, the deeply incised channel places the summer groundwater table well below the valley floor. This, combined with the historically deposited surface layer of mining spoils, makes conditions highly unfavorable for the development of riparian vegetation.

This type of channel (likely a Rosgen "F" type) is stable in that it doesn't move much laterally. Meandering is slight in most reaches: generally with a sinuosity less than 1.2 with short reaches above 1.5. This channel type does not generally produce good fish habitat unless there is an abundance of instream large roughness objects such as boulders, large logs and/or root wads to produce pools, instream cover and sorting mechanisms for spawning gravel.

 

4.2.2 Vegetation

There are several natural communities present along Secret Ravine: _ Naturalized Annual Grassland mantles the shallowest soils on the volcanic mudflows. It also is common on granitic soils no longer under cultivation. _ There is a Freshwater Seep just south of Interstate 80 about 500 feet beyond the end of China Gardens Road. _ Great Valley Willow Scrub is mixture of fast-growing deciduous shrubs including several species of willow, buttonwillow, coyote bush, sapling white alders and Fremont cottonwood. _ Great Valley Riparian Forest is best developed in the formerly dredged areas from the confluence upstream to near the hospital, where large valley oaks and Fremont cottonwoods form a nearly closed canopy. _ White Alder Riparian Forest is the principal riparian community along Secret Ravine above about 220 feet elevation, where the geology changes from sedimentary to granitic. _ Oak Woodlands dominated by interior live oak and blue oak probably mantled the entire Loomis Basin in pre-Spanish time.

Appendix B is an aerial photo atlas of natural vegetation along the stream corridor.

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4.2.3 Stream Habitat

Method Physical stream habitat is documented while wading upstream. Discreet channel features, called habitat types, are identified, measured, assessed, and recorded. Their proportion of the total stream is calculated. Most habitat types fall into three broad categories called riffles, runs, and pools. A set of stream features such as instream and overhead cover, and substrate quality is also graded.

Findings The proportion of riffle area to total area was small. This is a negative factor since most benthic macroinvertebrates (fish food) are produced in riffles. Riffles are also important in spawning as the optimal spawning conditions occur in the hydraulic transition zone between pool and riffles.

Sand was the overwhelming dominant substrate element. Sand reduces the amount of riffles by burying them. Excess sand also may block fry emergence from the gravel to the stream. Sand has degraded rearing habitat quality for aquatic invertebrates and salmon and steelhead rearing habitat. Sand has buried most of the cobbles and filled in the interstitial space where aquatic invertebrates live. Fish inhabiting a sand covered stream channel have shallower pools, smoother substrates, greater energy expenditures, less complex rearing habitat, and less food from the benthos. Sand contributes to unhealthy warming of the stream, by slowing water flow (travel time) and making the stream shallower, which allows greater solar penetration and more rapid warming.

4.2.4 Conclusions of existing conditions report

The existing deeply entrenched channel, which has apparently formed as a result of human land use practices, theoretically could be reconstructed to a more favorable stable form that could be sustained by current hydrologic and geomorphic conditions. Improvements such as channel re-construction or installation of roughness objects will increase pool depth, gravel quality, etc.

4.2.5 Recommendations of Existing Conditions Report

For restoration of vegetation Opportunities are greatest where the valley floor is broadest, mostly downstream of Rustic Hills. Terraces outside the flood channel are appropriate for valley oak-dominated communities. Floodplains are more appropriately planted with species of the cottonwood and willow dominated communities. While plantings within the bankfull channels may be considered, for example to armor a channel modification, they must be recognized as temporary.

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For stream morphology _ Develop and implement projects that introduce large roughness objects into stream channels to promote greater hydraulic diversity, bed scour for pools and sorting and flushing mechanisms for gravel. These objects could include logs, root wads and boulders placed along the edges of the entrenched channel. _ Where channels are excessively eroding in the headwaters, the channel banks should be regraded to create the natural three-stage channel configuration (low flow, bankfull and flood channel). This would be accomplished by excavating one side of the channel to the proper overall flood channel width with a flat geomorphic flood plain at the proper elevation and a transition slope no steeper than 2:1 _ Off Road Vehicle Access to the creek should be eliminated. Significant erosion and water quality impacts are occurring in several reaches. The entry points should be identified and closed off.

4.3 Stressors and Impacts

Table 1 lists basic requirements for each stage of the salmonid life cycle. Stressors affecting requirements are listed based on information in the existing conditions report and other observations. Stressors related to flow are included since sources of flow are in flux and it is possible that flows could change due to policies of local agencies. The table presents specific impacts of stressors on each stage of the life cycle.

Information in sections 4.3, 4.4, and 4.5 includes issues within all of the Dry Creek Watershed since getting salmonids to and from spawning areas in Secret Ravine is necessary to make habitat improvement in Secret Ravine worthwhile. Unlike river, estuary, and ocean problems, the entire watershed is within the scope of DCC and the Dry Creek CRMP. However, the focus of this AMP is on Secret Ravine since it is the most productive area for salmonids, and the area where the most sensitive life stages occur. There are other processes such as Placer County's Prop 204 grant, and City of Roseville's Riparian Management Plan that will address problems in other areas of the watershed.

Table 1 Summary of Stressors and impacts for salmon and steelhead in Dry Creek

4.4 Hypotheses Concerning Restoration and Management

In Table 2 hypotheses are made regarding the negative impacts of stressors on the salmonid life cycle. The hypotheses define the problem so that remedial actions and adaptive management studies can be formulated. Implementing the actions and studies will test the hypotheses and define future actions and studies. The following section discusses the basis for the hypotheses. The order of the hypotheses does not indicate order of importance. Hypotheses are listed in the same order as in the tables to make it easier to follow the discussion.

Table 2 Summary of Hypotheses

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4.4.1 Adult migration

Flow

Streams in the Dry Creek Watershed drain into Steelhead Creek (formerly the Natomas East Main Drainage Canal) a tributary to the Sacramento River that enters just upstream of the mouth of the American River. Each fall upstream migrating adult fall-run Chinook salmon must wait until there is sufficient runoff to increase flow in Steelhead Creek to enter the Dry Creek Watershed. Increased impervious surface in the watershed due to urbanization may result in earlier high flows that stimulate entry from the river to Steelhead Creek and Dry Creek, however, increased impervious surface may also lower baseflows due to reduced groundwater recharge. Major tributaries of the watershed are relatively small (first to third order streams) and have no major dams. The headwaters are at an elevation too low to collect snowpack, so the hydrology of the streams is dependent on rain in addition to groundwater and ag and urban returns. Secret Ravine is a major tributary in the Dry Creek Watershed.

Hypothesis 1: Dry Creek watershed is dependent upon surface runoff to attract upstream migrating adults

Years of late rainfall, change in effluent discharge from wastewater treatment plants, and change in additions to flow from Placer County Water Agency can result in reduced flow during the fall migration season and in non-optimal flows after migration has begun. Low flows contribute to higher water temperatures.

Currently the West Placer Regional Wastewater Treatment Plant being developed by Roseville has potential to reduce flows as effluent is transferred from the existing plant on Booth Road. This could have a negative affect on fall migration by increasing the periods that barriers are impassable.

Placer County Water Agency (PCWA) delivers water for domestic, agricultural, and municipal use. Water is imported from northern watersheds such as the Bear and Yuba and delivered through a series of canals built to supply mining interests during the gold rush and later used for agriculture. PCWA is increasingly important in providing municipal water for rapidly urbanizing Western Placer County. PCWA water enters the Dry Creek system in several ways. It enters Secret Ravine at the end of the Boardman Canal. This water has been impounded by a dam on Dry Creek at Watt Avenue for an agricultural user. PCWA water also is reported to enter Secret Ravine and other tributaries through leakage from inefficient canals. It also enters Secret Ravine from small tributary drainages that gather runoff from agricultural use.

As PCWA adapts to new end users and attempts to improve the efficiency of its delivery system, flows may change on Secret Ravine. The effect on stream ecology should be studied and solutions should be sought that minimize negative impacts.

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Hypothesis 2: Low flows in Dry Creek and tributaries result in unhealthy temperatures for all life stages.

Migration barriers Steven Thomas (2001), NMFS hydraulic engineer, examined a suspected barrier at the mouth of Secret Ravine and one downstream at the confluence with Cirby Creek and found both to have the potential to take salmon and steelhead. He suggested improvement options and recommended further studies. (See Appendix D.)

Hallock et al. (1970) studied the migration of adult Chinook salmon through the Delta in the 1950's and found that when the Head of the Old River Barrier was installed in fall 1964, adult salmon migrated through the mainstem San Joaquin River. However, when the barrier was not installed in fall 1965 and 1967, some of the salmon migrated through the South Delta. Their study suggests that barriers may block the flows that attract migrating adults and send them to non-natal tributaries (Mesick). Although Dry Creek and Secret Ravine have no total barriers, low flows make some barriers impassable. Pulses of fish move upstream past barriers during and after storms.

Hypothesis 3: Partial barriers in Dry Creek and Secret Ravine in combination with rainfall patterns and other sources of flow influence run timing and geographical distribution sending fish to less suitable habitat

In 1997 many fish were observed being taken by poachers at the Watt Ave. agricultural diversion on Dry Creek. When passage was opened that year poachers didn't return, and in subsequent years when passage has been required by CDFG, little poaching has been observed. Poaching has been observed and reported at barriers throughout the watershed.

Hypothesis 4: Partial barriers in Dry Creek and tributaries cause significant prespawning mortality due to poaching

Channel complexity The most obvious constraint to habitat quality in Secret Ravine is excess sand. Fish inhabiting a sand covered stream channel have shallower pools, smoother substrates, greater energy expenditures, less complex rearing habitat, and less food from the benthos (Li and Fields 1999). Vanicek (1993) in an evaluation of Dry Creek fisheries habitat notes that salmon require deep-holding pools during their upstream migration, especially during low water years or years of late rainfall. He notes that pool quantity and quality is poor in the lower reaches of Dry Creek. In recent years homeowners along Secret Ravine have often noted the decrease in pools and observed that sand seems to be filling them.

Hypothesis 5: Lack of channel complexity in Secret Ravine causes prespawning mortality due to excess expenditure of energy

4.4.2 Spawning

Flow Reduced flows can reduce the amount of usable spawning habitat which may increase redd superimposition rates (Mesick). Fish have been observed building redds on top of existing redds, particularly late in the season after a rain brings in fresh spawners.

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Hypothesis 6: Low flows cause superimposition of redds in Secret Ravine.

Channel complexity Fish must clean sandy gravel to spawn in Secret Ravine. When spawning area is limited by low flows, excessive sand, or beaver dams, redds are observed in substrate that is mainly sand with very little gravel. Swanson (2000) notes that the sand substrate problem in Secret Ravine is probably due both to excessive supply and (poor) channel hydraulics. The present hydraulics are monotonous due to an overly deep and wide channel. Large roughness objects such as woody debris and boulders in stream channels cause hydraulic diversity that scours pools and sorts and flushes gravel. Meanders and correctly sized bankfull channels also create hydraulic diversity. Hydraulic diversity increases spawning habitat area by sorting and cleaning gravels and by allowing fine particles to flow overbank during high flows.

Hypothesis 7: Lack of channel complexity in Secret Ravine leads to reduced spawning habitat and causes fish to build redds in substrate impacted by sand.

Hypothesis 8: Lack of channel complexity in Secret Ravine leads to reduced spawning gravel area and to superimposition of redds.

4.4.3 Incubation and emergence

Fall-run Chinook eggs incubate for about 43 days at 52oF whereas cooler temperatures increase the incubation period. After hatching, the alevins remain in the gravel until most of their yolk sac has been absorbed, which requires from 45 to 90 days after hatching (EA Engineering, Science, and Technology 1991). Based on this information and the timing of spawning, incubation and alevin development occurs from late October through March in most Central Valley rivers. This period is probably longer in the American and Yuba Rivers, and particularly the Feather River, where water temperatures are low compared to the San Joaquin basin and incubation and alevin development probably occur from September to April (Mesick).

Steelhead eggs are smaller than fall-run Chinook salmon eggs, and so steelhead eggs develop faster. At water temperatures of 55oF, incubation takes about 25 days (Barnhart 1991) and emergence requires about four to six weeks (Shapovalov and Taft 1954). Assuming that the spawning peak occurs in January and February, the peak period for incubation and emergence would occur from January through mid May. This corresponds to the catches of steelhead fry at the Hallwood-Cordua trap on the Yuba River in May and June (John Nelson, Department of Fish and Game, personal communication) (Mesick). Flow The survival of eggs to emergence depends on flow in the intragravel environment which affects dissolved oxygen concentration and water temperature. Low flow can make migration difficult and expose redds.

Hypothesis 9: Low flows in Secret Ravine increase mortality.

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Hypothesis 10: Low flows in Secret Ravine decrease healthy development

Channel complexity High concentrations of fine sediment in spawning riffles reduce intragravel flow and egg survival, and entomb embryos. Potential sources of fine sediments include (1) erosion due to removal of riparian vegetation and livestock grazing in the floodplain and along streambanks; (2) urban runoff; (3) incorrectly designed and inadequate maintenance of roads and culverts; and (4) leakage from canals, (5) unauthorized ORV trails and fords. (See DCC memo, 2000 regarding ATV access, Appendix D) Fine sediment has been observed entering Secret Ravine from small side streams. Although spawning salmon reduce the concentration of fines in their redds, high rates of fine sediment intrusion occur after redd construction due to storm runoff, redd construction activities from other nearby salmon, and possibly due to intragravel movement of fines (Mesick), (Li).

Observers are nearly unanimous in pointing out that sand is a major problem limiting spawning habitat in Secret Ravine. (Li, Swanson, Nelson, Meyers, Titus, Dvorsky)

Hypothesis 11: Lack of channel complexity in Secret Ravine causes excessive sand in gravel, which leads to lack of vigor and increased mortality due to poor percolation and entombment of fry.

Degraded channel complexity, defined as a relatively flat, uniform streambed, reduces diversity of water depths and velocities. Streambed complexity may be lost due to removal of large woody debris for flood control, urban hydrograph patterns that form incised channels that confine storm flows, and modified channel morphology from mining, agriculture, and urbanization. These elements create a flashy flow pattern during storms that erodes channels deeper and wider.

Hypothesis 12: Lack of channel complexity in Secret Ravine causes scouring of redds due to increased channel velocity at high flows.

4.4.4 Juvenile rearing

Juvenile fall-run Chinook salmon rear in the rivers beginning in late January after emergence. Recent screw trap studies in the Stanislaus and Tuolumne rivers suggest that a majority of the juveniles produced emigrate from the rivers as fry in February and March during peak flows (S.P. Cramer & Associates, various annual reports). In the Feather and American rivers, approximately 95% of the juveniles emigrate as fry from January through March (Snider and Titus 1995; Ted Sommer, Department of Water Resources, personal communication). Of the juveniles that rear in the rivers, they remain until mid April through early June. Juveniles rear in the rivers until they reach an average length of 70 to 80 mm in the Yuba River (S.P. Cramer & Associates 1995a), 80 to 100 mm in the Stanislaus and Tuolumne rivers (S.P. Cramer & Associates), and during low flow conditions to 100 to 110 mm in the Mokelumne River (BioSystems Analysis, Inc. 1992).

Juvenile steelhead rear in the Stanislaus and Feather rivers for at least one year when they typically reach between 200 and 300 mm in length (S.P. Cramer & Associates, Inc; Ted Sommer, Department of Water Resources, personal communication).

Such studies are not currently available specifically for Dry Creek and will be part of an adaptive management studies program.

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Non-natal Rearing: Non-natal rearing of fall-run Chinook salmon or steelhead juveniles may occur in the Dry Creek Watershed. The watershed consists of relatively low order streams similar to those used extensively around Chico by Chinook salmon not spawned in these creeks (Maslin et al. 1997, Maslin and McKinney 1994).

Hypothesis 13: Dry Creek and Secret Ravine support a non-natal population of juvenile salmon and steelhead.

Temperature As discussed in the Life History sections, the survival of juvenile salmon and steelhead rearing in the rivers is very dependent on water temperature. Temperature is affected by instream and riparian cover.

Hypothesis 14: Lack of riparian and channel complexity causes lack of vigor and mortality due to unhealthy temperature in Secret Ravine.

Water quality Many chemical byproducts of urbanization are present on the ground surfaces of the watershed. Impervious surfaces due to urbanization combined with efficient stormwater collection systems gather and deliver contaminants to the stream.

Hypothesis 15: Stormwater delivers pollutants from urban sources into Secret Ravine in quantities which negatively impact stream ecology.

Hypothesis 16: Pollutants from urban sources cause poor development and increased mortality of juvenile salmonids.

4.4.5 Juvenile migration

Juvenile fall-run Chinook salmon emigrate from the rivers to the Delta as fry in February through March, and as smolts from mid April through early June (Joe Merz, EBMUD, personal communication; Snider and Titus 1995; Ted Sommer, Department of Water Resources, personal communication; S.P. Cramer & Associates, Inc.).

There is very little information on the timing of steelhead smolt outmigration, because they emigrate as large fish (200-300 mm) and most avoid capture by screw traps. Screw trapping in the Stanislaus River suggests that migration occurs from February through May, but most were collected in April and May (S.P. Cramer & Associates, Inc.). In the Mokelumne River, fry and yearlings (mostly hatchery releases) are typically captured from February through July in screw traps at Woodbridge Dam (Joe Merz, EBMUD, personal communication). In the American River, steelhead fry were captured in screw traps in March and April whereas smolt-sized fish were captured between December and February (Snider and Titus 1995). In the Feather River, large schools of smolt-sized fish are observed in the river until September, which is presumed to be the end of the outmigration period (Ted Sommer, Department of Water Resources, personal communication) (Mesick).

Flow It is generally believed that high flows during outmigration improve fry and smolt survival. The possible mechanisms by which flow increases smolt survival include reduced predation rates and reduced entrainment at unscreened and inadequately screened diversions. However, high flows may strand juveniles in bypasses, and other high flow areas.

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Hypothesis 17: Low flows in Dry Creek and Secret Ravine increase mortality due to predation

Temperature Laboratory studies conducted in Washington indicate that the upper incipient lethal temperature for juvenile Chinook salmon is about 75oF (Brett 1952), whereas the highest growth rates occur between 60oF and 65oF (Banks et al. 1971). However, the San Joaquin basin has higher water temperatures than most other rivers that support Chinook salmon and new studies conduced by Chris Myrick at the University of California at Davis suggest that Central Valley fish have evolved to grow well at higher temperatures than previously reported. Myrick's studies were not completed and there is a need for additional work (Mesick).

The preferred rearing temperatures for steelhead are reported by Bjornn and Reiser (1979), Rich (1987), and Barnhart (1991) to be 45 to 60oF, with an optimum of about 50oF and an upper lethal limit of 75oF. However, these reports are based on laboratory studies of temperature tolerance for rainbow trout and not Central Valley steelhead. Chris Myrick at the University of California at Davis has recently completed temperature tolerance studies with Central Valley steelhead and the report has just been submitted for publication (Mesick).

Barriers Delayed spawning in the Fall results in a later emergence and outmigration of juvenile salmon. Secret Ravine juveniles that are in the lower reaches of Dry Creek and Steelhead Creek in late spring and summer likely encounter unhealthy temperatures during late outmigration.

Hypothesis 18: Partial barriers delay fall spawning resulting in outmigration during times of unhealthy temperature.

Studies suggest that predators congregate immediately downstream of small dams and diversion weirs, possibly feeding on the juvenile salmon as they spill over the dam. Preliminary studies on the Mokelumne River suggest that predation by striped bass in the Woodbridge Dam afterbay may be as high as 50% of total outmigration (Boyd 1994). Other small dams, such as Daguerre Point Dam on the Yuba River, Granlees Dam on the Cosumnes River, the many small diversion weirs on the Calaveras River, and a small illegal weir constructed on the lower Mokelumne River during dry years are examples where predators may congregate (Mesick).

Hypothesis 19: Partial barriers on Dry Creek and Secret Ravine provide opportunity for exotic species predators such as bass to congregate and prey on migrating juveniles.

Unscreened Diversions: There are many small unscreened or inadequately screened diversions in Secret Ravine, but entrainment rates have not been directly studied. Notable diversions on Dry Creek are the ag pump at Watt Avenue and the gravity fed out take at Hayer Dam. There are numerous small pumps for agriculture and homeowner use throughout the Dry Creek Watershed. Spring through fall diversions can significantly affect trout fry production especially in small streams. Diversion should be carefully studied, and kept out of low-flow, over-summering, headwater, refuge areas. Studies in the Delta suggest that entrainment rates increase exponentially with increases in diversion rate. The extent of entrainment in Secret Ravine and Dry Creek is unknown, however, small diversions may have a significant impact on juvenile salmonids due to the small size of the water column.

Hypothesis 20: Unscreened diversions on Dry Creek and Secret Ravine increase mortality by diverting fish from the stream.

Channel complexity Overhead cover provides protection from aerial predators and enhances habitat complexity (Li, 1999).

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Hypothesis 21: Lack of channel complexity causes increased predation due to lack of cover.

Food Supply Food supply and growth rates of juvenile salmon have not been extensively studied in most of the tributaries. Stomach content analysis of juvenile Chinook salmon in the lower American (Brown et al. 1992; Merz and Vanicek 1994) and Mokelumne rivers (Department of Fish and Game 1991; Merz 1998b) suggest that zooplankton from the upstream reservoirs and terrestrial macroinvertebrates occasionally supply as much as 50% and 25% of the fishes' diet, respectively. Invertebrate surveys have also been conducted in the Tuolumne and Calaveras rivers. Although the studies have not resolved whether the food supply limits the growth and survival of juvenile salmon, there are concerns that habitat degradation and contamination has reduced the supply of food from macroinvertebrates in the benthos and drift, plankton from reservoirs, and terrestrial invertebrates. High concentrations of fine sediments in the substrate may shift the benthic invertebrate populations toward smaller species that may be less useful as food for juveniles. It is also likely that channel incision, degraded riparian vegetation, and degraded streambed complexity have reduced the supply of organic detritus that is required by many invertebrate species for food (Allan 1995). The supply of terrestrial invertebrates may be affected by the spraying of pesticides near the floodplain and by levees/channel incision that reduce flooding which allows juveniles to feed in terrestrial zones and helps flush terrestrial invertebrates into the river.

Hypothesis 22: Lack of channel complexity causes decreased food supply due to lack of benthic macroinvertebrate and terrestrial habitat.

An increase in the roughness of the streambed provides a boundary layer that makes holding station less energetically expensive for salmon and steelhead. (Li, 1999)

Hypothesis 23: Lack of channel complexity causes unfavorable velocities resulting in excess energy expenditure and less than optimal growth.

4.5 Suggested Actions and Adaptive Management Studies

Table 3 summarizes remedial actions and Table 4 summarizes adaptive management studies. The restoration actions and adaptive management studies are based on the existing conditions analysis and the Conceptual Model. The actions and studies were categorized as high, medium, and low priorities based on the following criteria:

° Positive benefit for several life cycle stages,

° The severity of the impact of the stressor,

° Likelihood of gaining cooperation and/or permits necessary to take the action,

° Unanimity among observers regarding need for the action,

° Importance of knowledge to be gained by the action,

° Probability of obtaining resources necessary to take the action,

° Risk-management considerations (e.g., potential damage to people and property).

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Table 3 Summary of Suggested Remedial Actions for Stressors

Table 4 Summary of Adaptive Management Studies

High priority actions are those that will have the greatest positive impact and are most feasible to implement.

The Remedial Actions are categorized in the following discussion as either Education, Coordinated Management, or Restoration. It is assumed that Education and Coordinated Management remedial Actions will have a positive effect on watershed health by increasing the knowledge of parties whose actions impact the watershed.

The Restoration Actions are aimed at correcting stressors that have been identified by the Existing Conditions Report and other sources. The twenty-three Hypotheses express a probable relationship between stressors and Life Stage Function. It is expected that Restoration Actions will improve watershed functioning. Actually implementing the Restoration Actions will show how effective they are. If actions are correctly designed they will provide information about the validity of the Hypotheses. Implementing the Restoration Actions will also show whether they are cost effective and otherwise feasible.

In addition, Adaptive Management Studies are suggested in association with Remedial Actions. In some cases, Adaptive Management Studies are required to gather basic information about watershed processes before Actions can be implemented. In other cases Adaptive Management Studies will be designed to shed light on the validity of Hypotheses. Finally, Studies will show the effectiveness of Remedial Actions. In all cases the adaptive management studies should be designed to resolve the uncertainties in the hypotheses.

Tables 1-4 may be used to see which Stressors the Hypotheses are associated with. They can also be used to see which Hypotheses and Stressors the Remedial Actions and Adaptive Management Studies are associated with.

 

4.5.1 Education-Actions and Adaptive Management Studies

In many instances elected officials, agency and municipal staff, and local residents are unaware of the consequences of their decisions for stream resources. They may also be unaware of the importance of stream resources to their communities. Providing information at critical times can be an effective way to preserve and improve ecological function of stream resources. Flow Action 1 &endash; Provide decision makers with information on the importance of adequate groundwater as a component of stream ecology. High priority

Adaptive management study 1: Gather stream flow data for the watershed. Peak flow is available from Placer County Control District studies and City of Roseville monitoring stations. DCC has funding to develop methods to gather data throughout the day and through the seasons. Flow data will contribute to water quality studies, sediment studies as well as provide information about conditions for salmonid life cycle. High priority

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Migration Barriers Actions 4b and 4c: Provide decision makers and landowners with information about the salmonid life cycle in Dry Creek and Secret Ravine. Focus on migration requirements and how various stream installations affect them. High priority

Channel Complexity Action 7: Provide decision makers with information about how flood control programs affect the ecology of streams. Describe solutions to flood control that preserve stream function. Use existing material such as Placer County Flood Control and Water Conservation District's GOAL, POLICY AND STRATEGY RECOMMENDATIONS FOR STREAM MANAGEMENT IN PLACER COUNTY, 1991. Medium priority

Adaptive management study 9: Running hydraulic calculations to calculate the benefit of existing methods of stream maintenance that clear riparian vegetation. Use this information to propose the most beneficial maintenance programs. High priority

Action 9: Educate homeowners and landowners about stream ecology and how their actions can affect it. Distribute information such as the DRY CREEK WATERSHED map and description produced by Dry Creek Conservancy and the STREAM CARE GUIDE produced by Placer County RCD and Dry Creek CRMP. Attend local forums such as Municipal Advisory Councils and homeowners associations. High priority

Adaptive management study 11: Catalogue sediment sources and estimate their contribution to instream sediment loads. high priority

Water quality and temperature Actions 10, 11 and 14: Report the results of ongoing water quality investigations in the Dry Creek Watershed to a wide range of stakeholders including residents, government, schools, and business. Information is available from Dry Creek Conservancy programs funded by EPA and Prop 204 funding. Medium priority

Adaptive management study 12: Assess temperature data to determine when and where there are unhealthy temperatures, and to guide further temperature studies. High priority

Adaptive management study 13: Assess water quality data to determine if contamination is present at critical times in the salmonid life cycle. Use data to locate areas where water quality is a concern to salmonids, and sources of contamination. High priority

Adaptive management study 14: Assess stormwater quality to determine what pollutants are present, and if they are at a level unhealthy to salmonids. Locate source of unhealthy discharge. High priority

Adaptive management study 16: Locate sources of industrial and municipal discharge and assess the quality of the discharge. Low priority

Action 13: Provide residents with information about how their home maintenance practices affect stream ecology. Use existing materials from various agencies. Work with local agencies to distribute information. Medium priority

Adaptive management study 15: Gather information about contamination in water entering the stream from urban drains during the non-peak season. This should be coordinated with the more general studies of adaptive management study 13. Medium priority

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4.5.2 Coordinated Management-Actions and Adaptive Management Studies

Many agencies operate in the watershed and often take actions that directly affect streams. Dry Creek and Miners Ravine downstream of wastewater treatment plants are classified as effluent dominated by the Regional Water Quality Control Board. Although fall migrating fish depend on rainfall to provide sufficient flow, other sources such as wastewater and water deliveries are important to all stages of the life cycle. This water is sometimes said not to be "natural", but very little is natural in a watershed like Dry Creek where land uses have made major changes to the hydrological cycle. Stream and other resources require thoughtful, collaborative management. The Dry Creek Coordinated Resource Management and Planning Group (CRMP) was formed for that purpose.

Flow

Action 2: Provide stakeholders with information about the effect of effluent on stream flows and functioning. Work with agencies and local government to develop strategies that maximize healthy stream function. Medium priority

Action 3: Provide information to PCWA decision makers about PCWA impact on local stream ecology. Engage in PCWA management process to develop solutions that satisfy stream ecology requirements as well as water supply. Encourage PCWA to participate in the Dry Creek CRMP. Medium priority

Adaptive management study 2: Gather information about PCWA operations and determine how operations relate to stream flow data. High priority

4.5.3 Restoration-Actions and Adaptive Management Studies

The cumulative effects of mining, agricultural, and urbanization have degraded stream functioning. Stressors that have negative impacts have been identified in the conceptual model and the existing conditions report. The following actions are suggested to begin to restore proper stream functioning to benefit salmonids. It is expected that installation of these projects will significantly improve habitat on Secret Ravine.

Action 4a: Cooperate and coordinate with California Department of Water Resources Fish Passage Improvement Program to design and permit barrier improvements, and to work with landowners to fund improvements. The Fish Passage Improvement Program has chosen the Dry Creek Watershed as one of its projects. They have mapped barriers in the watershed and are evaluating habitat on Miners Ravine. The program participates in the Dry Creek CRMP and has begun a stakeholder process for Hayer Dam operation in lower Dry Creek. High priority

Adaptive management study 3: Determine run timing of salmon and steelhead from the Sacramento River to the spawning riffles in Secret Ravine. High priority

Adaptive management study 4: Design studies to estimate Steelhead spawning population. Observation can be difficult since Steelhead migrate during the season when storms increase flows and turbidity. High priority

Adaptive management study 5: Investigate methods to estimate salmon spawning population in order to assess the effectiveness of management and restoration activities. DCC has done surveys for the four years 1998 to 2001. More tightly designed studies are necessary to relate to juvenile outmigrant counts. Medium priority

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Adaptive management study 6: Survey predators such as bass during the outmigration season. Collect stomach samples from each species. Most predation is believed to occur below barriers. This survey would quantify the problem and provide a baseline for evaluating barrier improvements. Medium priority

Action 5 and 6: Work with local stakeholders to identify, design and install streambank stabilization, revegetation, instream complexity, and stream channel morphology projects. Projects should be controlled to determine what response in spawning, habitat use, or juvenile production occurs. Projects have been identified by the existing conditions report and the survey by Bishop (1997). A designed demonstration project and concept designs for five additional projects are included in Appendix C. High priority

There are substantial areas of public land where restoration may be installed:

Roseville - This section extends from the mouth to the Rocklin City line and is wholly within a preserve controlled by Army Corps of Engineers. All the restoration types named in action 5 and 6 are appropriate. High priority

Rocklin - Immediately upstream of the Roseville preserve development projects are projected to dedicate floodplain areas to the city. DCC and DC CRMP should work with City of Rocklin to improve degraded areas there. DCC has been working with the homeowner association upstream of Roseville. A good possibility of instituting homeowner-supported projects exists there. High priority

Off road vehicles &endash; Unauthorized roads are a major problem throughout the Roseville preserve and the area extending to Rocklin Road. DCC has provided a report of entry areas to City of Roseville and worked with City of Rocklin, Sutter Hospital, and residents to solve this problem. Rocklin and Roseville have increased policing of these areas and landowners have installed barriers, but controlling access is difficult because there are many entry points. (See DCC memo in Appendix D.) It is expected that land development projects will eventually limit access almost entirely. DCC was recently awarded funding for an education and signage program for the area. Restoration projects will be designed to exclude vehicles from sensitive areas. High priority

The Sierra College campus upstream of Rocklin Road includes a preserved section of creek. The Biology Department is interested in participating in habitat improvement projects. Channel complexity would be the most appropriate treatment. Dry Creek Conservancy has had a working relationship with the faculty for over 5 years. A recent Calfed grant facilitates further development of stream related projects there. Medium priority The Loomis Basin Regional Park owned by Placer County includes a section of stream near King Road that has been straightened and overgrown with blackberries. Placer County has shown interest in water quality and stream improvement projects by sponsoring a Prop 204 grant. DCC has met with landowners around the park and one downstream landowner adjacent to the park is very receptive to restoration projects. High priority

Projects in these areas would encompass nearly all the recommendations from the existing conditions report and subsequent reports by consultants. A pilot project designed for the Roseville preserve is included in an appendix. Five more conceptual designs for projects are also included along with a map of recommended treatments for specific areas.

In addition, Bishop, (1997) has identified similar projects that should be undertaken along the length of Secret Ravine. High priority

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Adaptive management study 7: Survey habitat types and type distribution. Li and Fields (1999) surveyed habitat for the existing conditions report. Subsequent surveys will determine if management and restoration have resulted in more optimal proportions of habitat types and in better quality habitat that support a diverse stream and riparian community. High priority

Adaptive management study 8: Assess juvenile habitat quality and complexity. Juvenile rearing habitat quality and complexity affect relative abundance of rearing salmonids. Few assessments have documented the value of various parameters. Depth, velocity, substrate, and cover are some of the parameters (Bovee 1978), however these parameters vary depending on water temperature (Smith and Li 1983). Sedimentation and fish food availability are generally not considered. Habitat complexity is an important habitat factor that has not been clearly defined. Complexity provides diverse habitat that allows spatial segregation that may increase relative abundance. For example, a simple pool that is excellent in quality will not support as many fish as an excellent and complex pool of the same dimensions. (Li) Low priority

Action 8: Identify problem stormwater entry points and design and install retrofit projects to reduce erosion and delivery of sediment. High priority

Adaptive management study 10: Survey riparian quality near stormwater outflows. high priority

Action 12: Design and install retrofit projects to reduce delivery of pollutants to the stream. Medium priority

4.5.4 Additional Adaptive Management Studies

Several other studies are suggested to gather information to improve understanding of salmonids in the Dry Creek Watershed.

Reproductive success

Adaptive management study 17: Conduct juvenile outmigration study on Secret Ravine. Rob Titus used a screw trap during the seasons of 1998-99 and 1999-2000 to estimate out migration (Titus, 2001, Appendix D). Subsequent efforts should gather data for comparison. Other methods of observing juveniles should be investigated. Medium priority

Adaptive management study 17a: Correlate outmigration with adult spawning. To accomplish this, accurate spawning population estimates are required and the age distribution of the adult fish must be known so that adult abundance can be segregated into broods (i.e., year classes) that correspond to a particular juvenile outmigration period. Medium priority

Adaptive management study 18: Analyze juvenile stomach samples to correlate with growth, health and habitat. Medium priority

Non-natal rearing

Adaptive management study 19: Investigate methods to study the extent of non-natal rearing in Secret Ravine. Medium priority

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5 IMPLEMENTATION

A number of resources will contribute to implementation of the Secret Ravine AMP.

Table 5

Secret Ravine AMP Resources

Resource

Period

The DWR Fish Passage Improvement Program will contribute resources to achieve consensus, design, and permits for barrier improvement.

Current

Inclusion of elements of the AMP in the Dry creek watershed management plan and the Roseville Riparian Management Plan will make it part of implementation of those plans using City and County resources.

2002-2003

Prop 204 programs will gather data for adaptive management studies.

Current-2002

319h grants awarded DCC will support monitoring and some restoration.

Current-2003

The DCC Calfed grant will develop GIS capabilities to organize data, will provide for volunteer training and involvement, will support flow monitoring, and will provide $20K for restoration on Secret Ravine.

2002-2003

A CDFG proposal to be developed would provide for design, permitting and some construction of projects on Secret Ravine.

2002- 2003

National Fish and Wildlife funds will support restoration projects.

2003

In summary, data gathering under existing programs will continue through 2003. Design and permitting of projects will take place in 2002. Construction of initial projects will begin in 2003.

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6 STUDIES PERTAINING TO TRIBUTARIES OF DRY CREEK

 

Secret Ravine Existing Conditions Report prepared for Dry Creek Conservancy:

Fields, W. 1999. The Benthic Macroinvertebrate Fauna of Secret Ravine Creek, Placer County California.

Holland, R. 2000. Vegetative Investigation Along Secret Ravine, Placer, County, California.

Li, S. and Fields, W. 1999. Assessments of Stream Habitat in Secret Ravine, Placer County, California, Spring, 1999.

Swanson, M. 2000. Reconnaissance Hydrology and Geomorphology Study of Secret Ravine, Placer County, California with Emphasis on Habitat Conditions for Fisheries.

Bates, G. 2000. Memo to Mark Morse regarding ATV access to Stoneridge open space.

Bishop, D. 1997. An Evaluation of Dry Creek and Its Major Tributaries in Placer County, California. Masters Thesis, California State University, Sacramento.

California Department of Fish and Game. 1964 to 1992. Memos to File.

Garcia and Associates. 1999, 2000, and 2001. Adult and Juvenile Salmonid Surveys, Water Temperature Monitoring, and Flow Measurements in Cirby and Linda Creeks, Placer County, California.

Moyle, P. 1985. Field notes on fisheries investigation for Dry Creek Watershed.

Nelson, John. 1997. Memo regarding Dry Creek, Secret Ravine, and Miners Ravine, Placer County.

Thomas, S. 2001. NMFS to DWR Fish Passage Improvement Program regarding fish migration barriers in the Dry Creek Watershed.

Titus, R. 2001. CDFG memo to files regarding Perennial Rearing Habitat for Juvenile Steelhead in the Dry Creek Drainage (Placer County).

Vanicek, D. 1993. Fisheries Habitat Evaluation, Dry Creek, Antelope Creek, Secret Ravine, and Miners Ravine. Prepared for EIP Associates.

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LITERATURE CITED

Allan, J.D. 1995. Stream Ecology: Structure and Function of Running Waters. London: Chapman and Hall. 388 pp.

Arkoosh, M.R., E. Casillas, P. Huffman, E. Clemons, J. Evered, J.E. Stein, and U. Varanasi. 1998. Increased susceptibility of juvenile chinook salmon from a contaminated estuary to Vibrio anguillarum. Transactions of the American Fisheries Society 127: 360- 374.

Banks, J.L., L.G. Fowler, and J.W. Elliott. 1971. Effects of rearing temperature on growth, body form, and hematology of fall chinook fingerlings. The Progressive Fish- Culturist 33(1):20-26.

Barnhart, R.A. 1991. Steelhead. Pages 324-336 in J. Stolz and J. Schnell, editors. Trout. Harrisburg, PA: Stackpole.

Bell, M.C. 1990. Fisheries handbook of engineering requirements and biological criteria. Fish Passage Development and Evaluation Program, U.S. Army Corps of Engineers, North Pacific Division. Portland, Oregon.

BioSystems Analysis, Inc. 1992. Lower Mokelumne River Management Plan, Technical Appendices B1-B2.

Bovee, K.D. 1978. Probability of use criteria for the family salmonidae. Instream Flow Information Paper No. 4. Cooperative Instream Flow Service Group. FWS/OBS-78/07: 91 pp.

Boyd, S. 1994. Striped bass predation in the Woodbridge Dam afterbay, April - May 1993. East Bay Municipal Utility District, Orinda, California

Brett, J.R. 1952. Temperature tolerance in young pacific salmon, genus Oncorhynchus. J. Fish Res. Bd. Canada 9(6): 265-323.

Brown, L., P. Moyle, and D. Vanicek. 1992. American River studies: Intensive fish surveys, March - June, 1991. Mineo Report, Department of Wildlife and Fisheries Biology, university of California, Davis, California.

Busby, P.J., T.C. Wainwright, G.J. Bryant, L. Lierheimer, R.S. Waples, F.W. Waknitz, and I.V. Lagomarsino. 1996. Status review of west coast steelhead from Washington, Idaho, Oregon, and California. U.S. Dept. Commer., NOAA Tech. Memo. NMFS- NWFSC-27, 261 p.

Carl Mesick Consultants, Aquatic Systems Research, and Thomas R. Payne & Associates. 1996. Spawning habitat limitations for fall-run chinook salmon in the Stanislaus River between Goodwin Dam and Riverbank. Draft report prepared for Neumiller & Beardslee and the Stockton East Water District.

Carl Mesick Consultants. 1998a. The effects of San Joaquin River Flows and the combined export rates of the Central Valley Project and the State Water Project during October on the number of adult San Joaquin Chinook Salmon that stray into Eastside rivers and the Sacramento Basin. Report prepared for the Stockton East Water District and Herum, Crabtree, Dyer, Zolezzi & Terpstra, LLP

Carl Mesick Consultants. 1998b. Studies of spawning habitat for fall-run chinook salmon in the Stanislaus River between Goodwin Dam and Riverbank from 1994 to 1997.

Cramer, S.P., S.D. Satterthwaite, R.B. Boyce, and B.P. McPherson. 1985. Impacts of Lost Creek Dam on the biology of anadromous salmonids in the Rogue River. Lost Creek Dam Fisheries Evaluation Phase 1 Completion Report, Volume 1. Oregon Department of Fish and Wildlife contract report subbmitted to U.S. Army Corps of Engineers, contract DACW57-77-C-0027, Portland, Oregon

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D'Aoust, V. and J.E. Merz. 1998. Angler survey of the lower Mokelumne River, San Joaquin County, California. September 1- October 15, 1997. Mimeo report to East Bay Municipal Utility District, Lodi, California.

Department of Fish and Game. 1991. Lower Yuba River Fisheries Management Plan. Report No. 91-1. 197 pp.

Department of Water Resources. 1994. San Joaquin River tributaries spawning gravel assessment: Stanislaus, Tuolumne, Merced rivers. Draft memorandum prepared by the Department of Water Resources, Northern District for the California Department of Fish and Game. Contract number DWR 165037.

EA Engineering, Science, and Technology. 1991. Report of Turlock Irrigation District and Modesto Irrigation District Pursuant to Article 39 of the License for the Don Pedro Project.

EA Engineering, Science, and Technology. 1993. Temperature and salmon habitat in the lower Tuolumne River. Prepared for the Turlock Irrigation District and the Modesto Irrigation District.

Gangmark, H.A. and R.G. Bakkala. 1960. A comparative study of unstable and stable (artificial channel) spawning streams for incubating king salmon at Mill Creek. California Fish and Game 46:151-164.

Gerstung, E.R. 1965. 1964 Fall Run King Salmon Inventory on Tributaries of the Natomas East Drain and the Natomas Cross Canal. California Department of Fish and Game Memorandum to Wm. O. White, Fisheries Manager II, Dated May 25, 1965.

Habicth, C., S. Sharr, D. Evans, and J.E. Seeb. 1998. Coded wire tag placement affects homing ability of pink salmon. Transactions of the American Fisheries Society 127:652- 657.

Hallock, R.J., W.F. Van Woert, and L. Shapovalov. 1961. An evaluation of stocking hatchery reared steelhead trout in the Sacramento River system. California Fish and Game Bulletin 114: 74 pp.

Hartwell, R.D. 1996. Upstream migration and spawning of fall run chinook salmon in the Mokelumne River, 1995, with notes on steelhead spawning, Winter 1996. Mimeo report to East Bay Municipal Utility District, Lodi, California.

Kreeger, K.Y. and W.J. McNeil. 1992. A literature review of factors associated with migration of juvenile salmonids. Unpublished manuscript for Direct Service Industries, Inc. October 23, 1992. 46 pp.

Lisle, T. and S. Hilton. 1991. Fine sediment in pools: an index of how sediment is affecting a stream channel. FHR Currents 6: 1-7.

Maslin, P., M. Lennox, J. Kindopp and W. McKinney. 1997. Intermittent streams as rearing habitat for Sacramento River chinook salmon (Oncorhynchus tshawytcha). USFWS Grant #14-48-0001-96724: 89 pp.

Maslin, P.E. and W.R. McKenney. 1994. Tributary Rearing by Sacramento River Salmon and Steelhead. Unpublished Report.

McEwan, D.R. 2001. Central Valley Steelhead. In Brown, R. I., ed. Contributions to the Biology of Central Valley Salmonids. Calif. Dept. of fish and Game Fish Bull. no 179, vol. 1: 1-43, page 23.

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McNeil, W.J. 1969. Survival of pink and chum salmon eggs and alevins. Pages 101-117 in T.G. Northcote, editor. Symposium on salmon and trout in streams. University of British Columbia, Institute of Fisheries, Vancouver, Canada.

Merz, J.E. 1998a. Association of fall chinook salmon redds and large organic debris in the lower Mokelumne River, California. In press. Report to the California Department of Fish and Game.

Merz, J.E. 1998b. Feeding habits of juvenile chinook salmon in the lower Mokelumne River, California. East Bay Municipal Utility District, Lodi, California.

Merz, J.E. and C.D. Vanicek 1996. Comparative feeding habits of juvenile chinook salmon, steelhead, and Sacramento squawfish in the lower American River, California. California Fish and Game 82(4):149-159.

Rich, A.A. 1987. Establishing temperatures which optimize growth and survival of the anadromous fishery resources of the lower American River. Prepared for McDonough, Holland and Allen, Sacramento, California, 25 pp.

Setka, J.D. 1997. 1996 Lower Mokelumne River chinook salmon Oncorhynchus tshawytscha spawning survey report. Mimeo report to East Bay Municipal Utility District, Orinda, California.

________. 1998. 1997 Lower Mokelumne River chinook salmon Oncorhynchus tshawytscha spawning survey report. Mimeo report to East Bay Municipal Utility District, Orinda, California.

Shapovalov, L. and A.C. Taft. 1954. The life histories of the steelhead rainbow trout (Salmo gairdneri) and silver salmon (Oncorhynchus kisutch) with special reference to Waddell Creek, California, and recommendations regarding their management. California Department of Fish and Game, Fish Bull. No. 98. 373 pp.

Smith, J.J. and H.W. Li. 1983. Energetic factors influencing foraging tactics of juvenile steelhead trout. Noakes et al. (eds.) Predators and Prey in Fishes. ISBN 90 6193 922 8, 1983, Dr. W. Junk Publishers. The Hague. Printed in the Netherlands.

Snider, B. and R.G. Titus. 1995. Lower American River emigration survey, November 1993 to July 1994. Department of Fish and Game, Environmental Services Division.

Snider, B., K. Vyverberg, and S. Whiteman. 1996. Chinook salmon redd survey, lower American River, Fall 1994. Department of Fish and Game, Environmental Services Division.

Snider, B. and K. Vyverberg. 1996. Chinook salmon redd survey, lower American River, Fall 1995. Department of Fish and Game, Environmental Services Division.

S.P. Cramer & Associates, Inc. 1995a. Evaluation of juvenile chinook entrainment at the South Yuba-Brophy Diversion headworks. Report prepared for South Yuba-Brophy and Yuba County Water Agency.

S.P. Cramer & Associates, Inc. 1995b. Effects of pulse flows on juvenile chinook migration in the Stanislaus River. Annual report prepared for the Tri-Dam Project.

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S.P. Cramer & Associates, Inc. 1996. Effects of pulse flows on juvenile chinook migration in the Stanislaus River. Annual report prepared for the South San Joaquin Irrigation District and Oakdale Irrigation District.

S.P. Cramer & Associates, Inc. 1997. Outmigrant trapping of juvenile salmonids in the lower Stanislaus River, Caswell State Park site, 1996. Final report submitted to the U.S. Fish and Wildlife Service under subcontract to CH2M Hill.

Staley, J.R. 1976. American River steelhead, Salmo gairdnerii gairdnerii, management, 1956-1974. California Department of Fish and Game, Anadromous Fisheries Branch, Admin. Report No. 76-2, 41 pp.

U.S. Fish and Wildlife Service. 1993. Working Paper on restoration needs: habitat restoration actions to double natural production of anadromous fish in the Central Valley of California. Volume 3. May 9, 1995. Prepared for the U.S. Fish and Wildlife Services under the direction of the Anadromous Fish Restoration Program Core Group. Stockton, CA.

Vaux, W.G. 1962. Interchange of stream and intragravel water in a salmon spawning riffle. U.S. Fish and Wildlife Service Special Scientific Report C Fisheries No. 405. Contribution No. 82, College of Fisheries, University of Washington.

Vaux, W.G. 1968. Intragravel flow and interchange of water in a streambed. Fishery Bulletin 66(3): 479-489.

Vyverberg, K., B. Snider, and R. Titus. 1997. Lower American River chinook salmon spawning habitat evaluation, October, 1994: An evaluation of attributes used to define the quality of spawning habitat. 44 pp.

APPENDIX A

Executive Summary of Secret Ravine Existing Conditions Report

Purpose The purpose of the study is to collect information to determine the existing condition of Secret Ravine. The ECR will serve as a baseline for assessing watershed function and will be used to develop an Adaptive Management Plan that will discuss impacts, hypotheses, and develop prioritized restoration actions for the Cry Creek Watershed. The data will serve as a baseline for evaluating the effectiveness of remedial measures as part of a long term monitoring program.

This study is funded by grants from the Anadromous Fish Restoration Program of the US Fish and Wildlife Service, and the National Fish and Wildlife Foundation Grassroots Salmon Initiative. A benthic macroinvertabrate study was funded separately with funds provided Dry Creek Conservancy by the 319h grant program of the State Water Resources Control Board.

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Methods

This study focuses on the stream corridor of the main stem of Secret Ravine. The area covered was approximately ten miles from the confluence with Miners Ravine to Rock Springs Road. (Map 1) The team approach was used to get a broad knowledge of the conditions. A multidisciplinary team consisting of Stacy Li, fisheries biologist, Wayne Fields, aquatic entomologist, Robert Holland, geobotanist, and Mitchell Swanson, geomorphologist worked on their respective aspects of the stream corridor. The corridor was walked in its entirety by three of the consultants. Homeowners and landowners throughout this area were notified of the study and several meetings were held to discuss the purpose of the study and include landowner concerns. The team met at areas of special interest or concern to discuss indications or approaches. The following sections draw from the consultants' reports.

Geomorphology

Hydrologic and Physiographic Setting

Secret Ravine is a perennially flowing stream that drains a 19.7 square mile basin within the Sierra Nevada foothills of western Placer County. Secret Ravine flows 10.5 miles from its headwaters in the Newcastle area (elevation 1285 feet) to its confluence with Miners Ravine Creek (elevation 165 feet) near Eureka Road in Roseville. (Figure 1) Streamflow is augmented by an unknown volume of tailwater delivered by Placer County Water Agency's irrigation releases. We observed flows in the early fall between 0.5 and 2-3 cfs. No continuous recording stream gage exists on Secret Ravine, but there is a flood activated warning gage operated by Roseville located in Rocklin near Sierra College Boulevard.

The Secret Ravine drainage basin experiences a Mediterranean climate with warm dry conditions between April and October and wet and mild weather between November and March. Average rainfall is 25.0 inches per year with most occurring during the peak rain months of December through February. The basin is underlain by granitic rocks of Mesozoic age and is capped unconformably by volcanic and volcaniclastic rocks of the Miocene Merhten Formation (occurring primarily in the lower watershed) and by Pleistocene alluvial fan and fluvial deposits of the Turlock Lake and Riverbank Formations. In the watershed hillslopes, Mehrten volcanic bedrock units develop shallow soils that generally have very high runoff rates. The granitic soils vary from shallow veneer over bedrock to deeper soils over zones of deeply weathered and decomposed granite.

Appenix A Fig. 1 - Study Area Line Map

Appendix A Fig. 2 - DEM Watershed map for Secret Ravine

Secret Ravine flows within a narrow valley underlain by recent alluvial deposits. The valley width expands in places to over 1,000 feet likely as the result of geologic controls. The central alluvial valley is bound by hills that are composed of granitic rock in the upper watershed and volcanic cap rock in the lower watershed. Soils in the alluvial valley vary from coarse-grained and highly permeable decomposed granite units (resulting from waste products of placer mining and sluicing and runoff from quarry spoils) to dense organic soils typical of perennial wetlands. The valley floor vegetation types include valley oak grasslands, riparian forest, and patches of seasonal wetlands.

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Channel Morphology

Stream channels are described by their, their slope (or gradient), width and depth (cross sectional shape) and their meander pattern as seen from above. The size and shape of a channel depend on the balance of water flow and sediment supply (sediment volume and sediment sizes). Channel morphology with a low ratio of width to depth and a meandering pattern with a sinuosity (the ratio of the channel length to the longitudinal valley length) greater than 1.3 is highly correlated to the favorable development of pools and gravel riffles important for good salmonid spawning and rearing habitat.

The stability of a channel is determined by its ability to pass the sediment load from upstream without dramatically changing channel width, depth or meander pattern. Channels may change pattern and shift location across an alluvial valley floor, but if they maintain consistent width, depth and meander characteristics they are considered "stable," or in "dynamic equilibrium."

GRADIENT

Different areas of a watershed have different slopes (or gradients) that determine the amount of sediment in the channel. For example, in the upper watershed steep channels and hillsides (the zone of erosion or depletion) are subject to net erosion because flow is too swift to allow for significant sediment storage. In the middle watershed (the zone of transportation) the stream flows within a sloping, alluvium-filled valley and temporarily stores sediment so that the sediment load coming in is equal to that going out. In the lower watershed (zone of net deposition) the stream meets its "base" level (such as a delta or the ocean) and sediment accumulates.

The gradient of a channel can be plotted by finding its lowest points all along the stream. The gradient of the channel may indicate the type and quality of its fish habitat. In general, channels over 2 percent gradient are confined in width and are entrenched within the low point of the valley; as is typical of headwater streams. Channels with gradients below 2 percent are often the classic meandering channel type with point bars, outer bank pools (good for adult salmonid migration, feeding and cover) and intervening gravel riffles (good for salmonid spawning and juvenile rearing). Properly functioning meandering channels have diverse water depth and velocity with stable size and shape, and produce high quality fish habitat in pools and riffles.

Figure 3 is a graph of the gradient of Secret Ravine and shows an average slope of 2.4% in the upper third of the stream, and an average slope of about 0.6% in the lower two thirds. This fits the model of a headwaters stream making a transition to a middle watershed pattern that can have a classic meandering pattern rich in salmonid habitat. However, Secret Ravine has other channel characteristics that limit its habitat value.

CROSS SECTIONAL SHAPE

Figure 4 shows a cross-section of an idealized valley. The channel has three stages: the low flow channel which often carries well over 90% of the flows and contains much of the aquatic habitat important for fish; the bankfull channel which carries flows of 1.5 to 3 year storms; and the geomorphic flood plain (not FEMA "100-year flood plain") which is the low, flat area adjacent to the bankfull channel and is subject to frequent flooding and fine sediment deposition.

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The bankfull channel carries small- to intermediate-sized floods that occur fairly often and has the most influence on channel size and shape. The bankfull channel is indicated by features such as the level of the flood plain surfaces, the predominant scour lines, and in some climates by particular species of vegetation. The flood channel carries the larger flows, generally no less than a 5-year event. The flood channel, ultimately bound by the surrounding hillslopes, includes older geomorphic flood plain surfaces termed "terraces", that are the result of channel incision or entrenchment into the valley floor. Terraces are formed by climatic change, tectonic uplift, progressive erosion, or a short term filling by a large flood event.

SECRET RAVINE MORPHOLOGY

Secret Ravine flows within a channel that is entrenched within the alluvial valley floor. This appears to be the result of: 1) historical filling of the alluvial valleys with re- deposited placer and quarry mining spoils; and 2) possible channelization for subsequent agricultural use and urban development. As a result, Secret Ravine is not close to the ideal three stage channel described above. The channel is typically 6 to 8 feet deep (in some reaches over 12 feet deep), flat bottomed and rectangular in shape and anywhere from 10 to 25 feet wide. A large range of flows are contained within the channel which leads to further lateral and vertical erosion. In addition, the ability of the channel to dispose of excess sediment by carrying it onto the floodplain in overbank flows is diminished. Moreover, the deeply incised channel places the summer groundwater table well below the valley floor. This, combined with the historically deposited surface layer of mining spoils, makes conditions highly unfavorable for the development of riparian vegetation.

Appendix A Fig. 3 - Longitudinal profile of Secret Ravine measured upstream from cnfluence with Miner's Ravine.

Appendix A Fig. 4 - Idealized valley floor cross-section showing typical geomorphologic features

This type of channel (likely a Rosgen "F" type) is stable in that it doesn't move much laterally. Meandering is slight in most reaches: generally with a sinuosity less than 1.2 with short reaches above 1.5. This channel type does not generally produce good fish habitat unless there is an abundance of instream large roughness objects such as boulders, large logs and/or root wads to produce pools, instream cover and sorting mechanisms for spawning gravel.

In disturbed watersheds such as Secret Ravine, it may be possible to promote a shift from a stable degraded channel form with low habitat value to a form that sustains better fish habitat. A full geomorphic assessment of Secret Ravine should develop over time as a habitat improvement program develops and the appropriate hydrological and geomorphic data is collected. Analysis of the data can lead to designs for channels with improved hydraulics and habitat value.

Vegetation

There are two reaches along Secret Ravine with different geology, different valley forms, and different riparian vegetation. The upper three quarters of the stream is incised to numerous granitic local bedrock controls. Fine bedload accumulates above these controls, but there is little out-of-channel alluvium. The lower quarter of the stream course flows over Merhten volcanics. Here, there is a broad alluvial floodplain and field evidence of on-going overbank deposition in this lower reach. Valley oak forests develop on the highest alluvial surfaces, while cottonwood forests do better on the lower floodplain. The bankfull channels flood so frequently that only willows or alders can persist. Unfortunately, most of the terrace and floodplain in this lower reach has been mined and the original topography and vegetation have been obscured.

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The historical land uses have interacted with these geologic reaches resulting in several different plant communities today: Naturalized Annual Grassland mantles the shallowest soils on the volcanic mudflows. It also is common on granitic soils no longer under cultivation. It typically includes soft chess (Bromus hordaceus), ripgut brome (B. diandrus), medusa grass (Taeniatherum caput-medusae), and filaree (Erodium lotrys). Star thistle (Centaurea solstitialis) and wild lettuce (Lactuca serriola) have increased locally in the years since cattle were removed.

There is a Freshwater Seep just south of Interstate 80 about 500 feet beyond the end of China Gardens Road. A low levee parallel to the freeway appears to be impounding enough ground water to support a small clump of cattails (Typha latifolia) and a few willow clumps (Salix lasiolepis, S. exigua). These are surrounded by several hundred feet of weedy hydrophytes, especially baltic rush (Juncus balticus).

Great Valley Willow Scrub is mixture of fast-growing deciduous shrubs including several species of willow (Salix exigua, S. lasiolepis, S. laevigata), buttonwillow (Cephalanthus occidentalis), coyote bush (Baccharis pilularis consanguinea), and sapling white alders (Alnus rhombifolia) and Fremont cottonwood (Populus fremontii). It is an early seral community that quickly colonizes alluvial deposits disturbed during flooding. Trees that do establish seldom last many decades before they are toppled by undercutting or floating debris. Most stands consist of a single file thicket of shrubs up to 30 feet wide. These thickets are very efficient at retaining sediment during over-bank flows. The shrubs that grow here have well developed vegetative reproduction and quickly form enormous rootwads capable of enduring 100 year flows. Even stands that are completely decapitated by saltating bed load during peak flows can recolonize a bar within a growing season.

Great Valley Riparian Forest is best developed in the formerly dredged areas from the confluence upstream to near the hospital, where large valley oaks (Quercus lobata) and Fremont cottonwoods (Populus fremontii) form a nearly closed canopy. Upstream of the dredged area, Fremont cottonwoods are much less conspicuous, but large valley oaks continue to the contact with granite. There also is a small stand of cottonwood riparian forest near Sierra College.

White Alder Riparian Forest is the principal riparian community along Secret Ravine above about 220 feet elevation, where the geology changes from sedimentary to granitic. The stream is incised in bedrock and the riparian corridor is correspondingly narrow. Fast-growing alders (40 feet in 10 years) capitalize on light gaps and can reach the canopy, thereby shading out competitors. Alders cast dense shade and produce copious, nitrogen-rich leaf litter that is an important stream fauna resource. Alders are very shallow-rooted: only about 2 feet of alluvium over bedrock is necessary.

Oak Woodlands dominated by interior live oak (Quercus wislizenii) and blue oak (Q. douglasii) probably mantled the entire Loomis Basin in pre-Spanish time. All surviving woodlands in the basin include these two species, frequently plus valley oak and grey pine (Pinus sabiniana). Canopies usually are closed and abundant, persistent leaf litter keeps understories fairly open. Many surviving oak woodlands are in areas that were placer mined before agricultural development began. Apparently the mining rendered the land useless for agriculture and thus the forest never was cleared. Other oak woodlands survive in areas not served by gravity irrigation water.

Irrigated orchards replaced native oak woodlands where imported water was available. Irrigation tail water would have supplemented late season flows compared to pre-Spanish conditions, thereby irrigating riparian vegetation that was re-establishing along the water course in the wake of gold extraction.

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Stream Habitat

Method

Physical stream habitat is documented while wading upstream. Discreet channel features, called habitat types, are identified, measured, assessed, and recorded. Their proportion of the total stream is calculated. Most habitat types fall into three broad categories called riffles, runs, and pools. A set of stream features such as instream and overhead cover, and substrate quality is also graded.

Findings

Proportional area of run types was about 71%, pool types about 18%, and riffle types about 9%, with several minor habitat types comprising the rest. This is considered a less than ideal composition since most benthic macroinvertebrates are produced in riffles. Food supply for salmonids decreases with distance from riffles. Fish are dependent on insects from the bank (terrestrial drift) as they get further from riffles.

Sand was the overwhelming dominant substrate element representing 68% of the observations. The excess sand reduces the amount of riffles by burying them. Excess sand also may block fry emergence from the gravel to the stream. Sand has degraded rearing habitat quality for aquatic invertebrates and salmon and steelhead rearing habitat. Sand has buried most of the cobbles and filled in the interstitial space where aquatic invertebrates live. Fish inhabiting a sand covered stream channel have shallower pools, smoother substrates, greater energy expenditures, less complex rearing habitat, and less food from the benthos. Sand contributes to unhealthy warming of the stream, by slowing water flow (travel time) and making the stream more shallow, which allows greater solar penetration and more rapid warming.

Ratings for stream features were as follows:

Feature
Quality

Substrate roughness

Poor due to sand

Interstitial space

Poor due to sand

Benthic aquatic invertebrate habitat

Poor-sand decreases riffle frequency and quality

Salmonid feeding lanes

Poor

Surface turbulence

Good

Instream cover

Poor-channel simplified by sand

Riparian vegetation cover

Fair

Woody debris

Poor-very little

Overhead cover

Fair

Terrestrial drift

Fair

Juvenile rearing quality

Fair

Typical pool depth

Good

Substrate percolation

Good-despite sand

Overall rating

Fair-sand is the major constraint

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ECR Conclusions

The existing deeply entrenched channel, which has apparently formed as a result of human land use practices, theoretically could be reconstructed to a more favorable stable form that could be sustained by current hydrologic and geomorphic conditions. The slope of the channel and valleys (less than 1 percent) is within the range of a less entrenched, shallower and more sinuous channel that would have greater habitat value for fish (a Rosgen "C" channel type). It would also raise groundwater levels to promote favorable conditions for riparian and wetlands vegetation. The predominance of sand substrate in Secret Ravine is likely due to widely disturbed sources of channel erosion, historical disturbance associated with quarries and placer mining, and unfavorable channel morphology that does not flush pools and riffles. The sand substrate problem is probably due to both excessive supply and channel hydraulics. Improvements such as channel re-construction or installation of roughness objects will increase pool depth, gravel quality, etc. The present hydraulics are monotonous due to an overly deep and wide channel. Hydraulic diversity is needed to acquire the diversity in channel topography. These improvements aim to increase the relief within the channel so that there are drops into deep pools and rises to shallow riffles. The average drop will be the same, but the channel bottom will rise and fall.

Opportunities for restoration Of vegetation

The vegetation is in remarkably good shape given what has transpired in the watershed within the life spans of the dominant plants. The worst weed is wild blackberry, and most of what it infests is mine tailings. Any effort to control the blackberry, however, will need to address what plant will replace it in the landscape.

Restoration opportunities are greatest where the valley floor is broadest, mostly downstream of Rustic Hills. Terraces outside the flood channel are appropriate for valley oak-dominated communities. Floodplains are more appropriately planted with species of the cottonwood and willow dominated communities. While plantings within the bankfull channels may be considered, for example to armor a channel modification, they must be recognized as temporary.

Of stream morphology

a. Develop and implement projects that introduce large roughness objects into stream channels to promote greater hydraulic diversity, bed scour for pools and sorting and flushing mechanisms for gravel. These objects could include logs, root wads and boulders placed along the edges of the entrenched channel. Heavy equipment is usually required, but there may be some opportunities to move objects from the channel banks into the channel. These projects, when done correctly, would have immediate benefits.

b. Low-tech in-channel projects should be installed on a pilot project basis. These include log and hay bale structures (or perhaps coir biologs) planted with live willow stakes placed in the channel to reduce width, confine flow and create deeper pools and overhead cover. There are many places where this technique could be applied.

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c. Where channels are excessively eroding in the headwaters, the channel banks should be regraded to create the natural three-stage channel configuration (low flow, bankfull and flood channel). This would be accomplished by excavating one side of the channel to the proper overall flood channel width with a flat geomorphic flood plain at the proper elevation and a transition slope no steeper than 2:1 (horizontal:vertical). The channel dimensions would be determined by specific geomorphic survey. All surfaces would be re-vegetated with native species, especially willow (Salix sp.), sedges and other species that provide good erosion control. Logs, boulders and other elements should be incorporated. The project should be constructed under the supervision of an experienced stream restoration specialist to conduct favorable "fit-in-the-field" work. A planting, erosion control and irrigation plan must be completed and implemented in order to ensure success. An engineering analysis would be required to ensure no impact to adjacent banks or properties.

d. Re-construct channels in the lower alluvial valleys of Secret Ravine using a geomorphic design to 1) eliminate the entrenched condition and chronic sediment input from channel banks; 2) increase channel sinuosity to improve substrate conditions; and 3) improve conditions for riparian vegetation and wetlands by elevating the groundwater table. This would be accomplished by first constructing a new channel at a higher elevation on the valley floor in a new alignment located away from the existing channel. The new channel would be vegetated and irrigated for a period of about two years to stabilize the banks. Flow would be introduced in the spring of the third year and the old channel would be partially filled to prevent stream capture. Implementing this project appears technically feasible in several reaches summing to perhaps over 5,000 linear feet of channel. The benefits for fisheries would be substantial and the project presents an opportunity to restore stream habitats to their likely pre-Gold Rush Era condition and geomorphic processes.

[Note 1: A similar project is presently under construction on Trout Creek in South Lake Tahoe. The stream experienced channelization and impacts due to Comstock Era logging, grazing and road building. The Trout Creek project is more complicated than the Secret Ravine Project and is costing about $150 per linear foot.]

[Note 2: There could be significant flood control benefits in small floods if the channel were restored. Overbank flows would occur more often and flood plain storage would be increased. Local flood impacts would have to be addressed as part of the channel design].

e. Off Road Vehicle Access to the creek should be eliminated. Significant erosion and water quality impacts are occurring in several reaches. The entry points should be identified and closed off.

APPENDIX B AERIAL PHOTO ATLAS OF NATURAL VEGETATION

An air photo atlas of natural vegetation along portions of Dry Creek, Miner's Ravine, and Secret Ravine. The photobase has been electronically form original air photos nominally scaled at 1,000 ft per inch. The phtomosaic has not been georeferenced. The photos were taken in March, 1995. Several large developments have gone in within the study area that are not visible in the photos. Polygon boundaries reflect conditions in August, 1999.

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Click an image for a larger view.

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APPENDIX C Restoration Plans

APPENDIX D RELATED MEMOS