Sonoma Valley Watershed Station Work Plan 2000
Sonoma Ecology Center
Technical Advisory Committee
Research Program Work Plan
Sonoma Ecology Center, 205 First Street West, Sonoma, CA 95476
(707) 996-9744, , http://www.sonomaecologycenter.org
INTRODUCTION
The Sonoma Ecology Center’s Technical Advisory Committee (TAC) directs and guides the research of the Sonoma Valley Watershed Station (SVWS). The TAC consists of Sonoma Ecology Center (SEC) staff, local professionals, and scientific experts with background in planning and implementing watershed research plans. The TAC's role of mentor for the SVWS includes: designing of sampling protocols and data sheets, training volunteers and interns, performing QA/QC of volunteer data, and conducting data analysis and interpretation.
As a community-based organization, SEC is charged with facilitating community understanding of technical watershed data by collecting and integrating multiple types of information. SEC also plays a key role by interpreting others’ scientific data and analyses in terms people can relate to, whether they are policy-makers or concerned residents. In this way, the SEC’s science programs promote the health and sustainability of Sonoma Valley ecosystems.
Over the past two years, the SEC’s Sonoma Valley Watershed Station has been implementing a research plan adopted by the TAC in 1997 to begin work on three goals:
· Restore salmonid fish populations
· Preserve and restore riparian areas
· Preserve and protect water quality and quantity
· Self-sustaining populations of all native plant and animal species, including humans
The conditions that these goals seek to achieve are three strong indicators of healthy ecological conditions necessary for sustainable communities. SEC is working towards these (and other) goals that will help support natural and human systems to maintain Sonoma Valley's high quality of life. In order to achieve these three goals, our work at the Watershed Station has focused on three areas: establishing baseline values for evaluating stream ecosystem health, measuring stream parameters critical to the survival of salmonids in Sonoma Creek, and identifying priorities for future research and restoration activities.
As in the TAC work plans for 1996-1999, this work plan extends the studies already underway and builds on them with new research objectives. The scope of work outlined in the plan below applies to watershed research only and is not intended to detail restoration or implementation measures. These programs are detailed in other documents.
SVWS RESEARCH OBJECTIVES
Scientific research focused on restoration planning should follow a framework of questions to define a process for watershed assessment.
· What are the desired conditions?
· What are current, baseline conditions?
· What are the obstacles to desired conditions? What are limiting factors? How do they interact?
· What can be done to alleviate the obstacles or remove them? What are the options, opportunities, or alternatives for achieving desired conditions?
· What is the community’s vision? Which alternatives fit the vision?
· What is the sequence of steps required to accomplish the best alternative?
The research described herein applies this framework to five ecological indicators: water quantity, water quality, sediment, plant communities, and wildlife. Specific research objectives are identified for each indicator. In many cases, restoration activities will be identified by the synthesis of data and integration of analyses.
1.0 Water Quantity
Many tributaries in our watershed have intermittent and ephemeral flow characteristics which heighten the ecosystems’ sensitivity to changes in water quantity. Winter flows, including peak flows are particularly important in maintaining channel morphology and function. Low flows are critical in providing over-summering habitat for many aquatic species, including salmonids. Land and water use by humans can have dramatic effects on the timing and intensity of flow. The following water-quantity assessment will be conducted to monitor in-stream flow conditions, analyze effects on fish populations, evaluate the relationship to human activities, and quantify the availability of water for human use.
1.1 PRECIPITATION
The watershed receives most of its precipitation in the form of rain, although occasional snow falls in the headwaters of Sonoma Creek. The winter rains account for the annual input of water into the watershed system, and provides a key baseline number for tracking the response of streams to rainfall, as well as, water availability for human and natural needs all year long.
During the rainy season, Stream Stewards will collect rainfall data daily. An automated rain gage was temporarily installed last wet season and a permanent gage is planned for the 2000 season which will improve the quality and consistency of the data. An automated monitor installed at the Sonoma Mission Inn Golf Course within the last year is recording evapotranspiration potential.
1.2 DISCHARGE
1.2.1 PEAK FLOW
Flow within Sonoma Creek Watershed varies widely depending on rainfall, topography, and conditions within each tributary’s subwatershed. The interaction of these factors influences in-stream sediment conditions, channel complexity, and other water-quality parameters. Increases in peak intensity and length of time over which they are sustained have been shown to cause changes in water quality and channel morphology. Sediment moves during high flow events. Increases in peak flow from changing land use practices (e.g., changes in vegetative cover, increased amount of impervious surface) may cause increased stream power. Increased stream power can result in accelerating downstream bank erosion, channel incision, loss of large woody debris and complex channel morphology, and coarsening of streambed materials.
SEC has organized a collaborative funding strategy to establish an automated station(s) in Sonoma Creek. The U.S. Army Corps of Engineers (USACE), U.S. Geological Survey (USGS), and RWQCB have agreed tentatively to fund installation and the critical first few years of operations for the station(s). SEC is probing local agencies for long-term funding opportunities. The USGS will install the station and perform operations and maintenance in following years, with technical assistance from SVWS staff. We will fine-tune the peak-flow monitoring program to complement the automated flow gauging system. Collection of discharge data by Stream Stewards will resume after analysis of existing information is completed, following protocol revision if necessary.
RESEARCH OBJECTIVES
n establish current conditions for monitoring trends
n compare current situation with historical data
n help analyze sediment data, calibrate sediment production model
n test relationship to instream habitat conditions (spawning gravel, etc)
n test relationship to land use
1.2.2 LOW FLOW
In a region with 6 months of drought, low flows are an important indicator of water quantity. The interaction of low flow with water quality parameters is a critical link in determining suitable habitat for many aquatic species, including steelhead.
Low flow evaluation was initiated in June 2000 and it will continue for three years. Data will be collected during months when the stream potentially loses flow to a lowered water table. Selected low flow monitoring locations are not only proximal to known nursery habitat but are also under bridges with abutments where staff gauges could be installed. A rating curve will be developed for each station to correlate stage with discharge. With staff gauges installed and rating curves prepared, volunteer monitors will be able to read streamflow conditions from the gauges.
RESEARCH OBJECTIVES
n establish baseline low flow values for monitoring trends in key tributaries
n compare current low flow values with historical data
n assess problem areas for fish rearing (pool numbers and depths)
n link to water quality, temperature studies
1.3 GROUNDWATER
SEC is working in conjunction with the Sonoma County Water Agency to convert well log data from 5000 sites in the valley to GIS-linked database files. SEC is also mapping groundwater recharge zones. The land use data will be applied to determine the changes in soil permeability from pavement. These groundwater data will be useful in determining the amount of water potentially available (or unavailable) for new allocations.
1.4 SURFACE STORAGE
1.5/1.6 WATER ALLOCATIONS/WATER BUDGET
Currently there is no system to evaluate water allocations and availability of ground and surface water for withdrawal. This watershed is particularly sensitive to low flows during months when water withdrawals are at their greatest. Summer water use has the potential to severely limit steelhead populations and aquatic communities in general.
We will research water rights allocations and withdrawals within the watershed and investigate how much water is being used by riparian and appropriative abstraction. Using an estimate of the annual input from rainfall, we will examine the interaction of withdrawal timing and amounts with expected and measured water available. This information will provide a long-term monitoring tool to track how much water might (or might not) be available for new allocations. The data will be examined on a sub-watershed basis where possible.
Research Objectives
n assess expected discharge from precipitation input and compare it with measured discharge
n assess how and where fish habitat might be affected by groundwater and in-stream withdrawals
n track how much water might (or might not) be available for new allocations
2.0 Water quality
Basic biological, chemical, and physical properties of streams are important indicators of stream health and are crucial factors in determining the types and numbers of animal and plant species that can survive within the wetted portion of the stream. Sonoma Creek is presently listed as impaired for nutrients, pathogens, and sediment under Clean Water Act Section 303(d). Possible sources of water-quality degradation include erosion, runoff, septic systems, yard waste, oil and grease, and agricultural fertilizers and pesticides. Interpretation of the biological, physical, and chemical information from water quality monitoring will help to identify limiting factors for the steelhead population, pinpoint sites for further monitoring, and provide a blueprint for ecological restoration in the watershed.
2.1 TEMPERATURE
Water temperature is an important factor for steelhead survival as well as an indicator of riparian canopy and stream health. Previous water monitoring reports have shown high temperatures in sensitive stream reaches for steelhead. The link between temperature and low flow is extremely important to understanding limiting factors for salmonids.
Stream stewards will continue to monitor water temperature at key sites. Analysis will be integrated with other data about steelhead needs. The relationship between riparian canopy, land use, and temperature will be evaluated.
RESEARCH OBJECTIVES
n compare current situation with previous data
n identify problem areas for steelhead
n link temperature to low-flow monitoring
n test relationship with land use and riparian canopy
2.2 WATER CHEMISTRY
Water-quality monitoring will examine factors including but not limited to: dissolved oxygen (DO), conductivity, and pH. Results of water-quality testing will be used to draw conclusions about the specific parameters as they relate to stream health. Sampling will be conducted in three teams, following the protocols developed by the EPA in Volunteer Stream Monitoring: A Methods Manual. Analysis will build on existing studies based on EPA STORET data (“A day on Sonoma Creek,” 1997).
RESEARCH OBJECTIVES
n establish baseline values for monitoring trends
n compare current situation with historical data
n identify point and non-point sources of pollution
n identify problem areas for steelhead
n test relationship of water quality to land use
n identify restoration opportunities
2.2.1 PESTICIDES
Various chemical pesticides are used by agricultural, residential, and governmental operations throughout Sonoma Creek Watershed. These chemicals have various risks to human health, but their impact on terrestrial and aquatic ecosystems is mostly unknown. Pesticides can be toxic to algae and BMIs, two primary aquatic food sources, in relatively low concentrations. Recent research has also implicated pesticides in behavioral and olfactory damage to salmonid individuals.
Monitoring for pesticide impacts starts with understanding which chemicals are being applied where and in what quantity. Using Pesticide Use Report data from the county, we will create a GIS database of pesticide use in the Sonoma Creek Watershed over the past decade. We will identify high use areas and potential conflict areas for salmonid populations. This data will be used to select pesticide monitoring sites.
RESEARCH OBJECTIVES
n establish trends using 10+ years of PUR data
n compare high use areas to BMI monitoring and key steelhead reaches
n assess relationship to land use
n select water monitoring sites for pesticides
2.3 BENTHIC MACROINVERTEBRATES
Because of their diversity, ubiquity, and importance in the stream community as a major link in the food web, benthic macroinvertebrates (BMIs) provide an important indicator of aquatic health. BMIs are a major food source for salmonids and may be a limiting factor for survival of juvenile fish.
In spring 2000 we began sampling BMIs using the California EPA Stream Bioassessment Procedure at twelve sites. This protocol is a simplified version of EPA’s Rapid Bioassessment Procedure; it prepares us to implement the Rapid Bioassessment Procedure next year. Joseph Brumbaugh, a locally knowledgeable invertebrate biologist, is assisting in developing macroinvertebrate key and tolerance categories and in training volunteers. Replicate samples are being identified to family at the SVWS laboratory. The samples are grouped into three pollution-tolerance categories and used to calculate a water-quality index. The results will be analyzed to draw conclusions about the biological health of the sampled sites.
RESEARCH OBJECTIVES
n establish baseline community index values for monitoring trends
n assess the biological health of key sites
n test relationship to land use
n identify restoration opportunities
3.0 Sediment
California’s Clean Water Act Section 303(d) lists Sonoma Creek as impaired by sediment. Important beneficial uses include preservation of rare and endangered species, fish migration, and instream freshwater habitat. Water quality objectives are included in the RWQCB Water Quality Control Plan (Basin Plan) for the San Francisco Bay Region. The plan says that turbidity (due to waste discharge) shall not increase by more than 10 percent where natural turbidity is more than 50 nephelometric turbidity units (NTU). For nonpoint sources (e.g., of sediment), no numeric value has been established, but surface waters are expected to be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Interpretation of the data relating to excessive sediment yield will help to provide information to the community regarding human-induced sedimentation, identify turbidity-related limiting factors for steelhead, pinpoint sites for continued monitoring, and identify restoration sites in the watershed.