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Well Levels and Streamflow Being Monitored
by the Carneros Creek StewardshipIn their effort to protect and enhance the resources of the Carneros Creek watershed, the Carneros Creek Stewardship, with assistance from the RCD, is beginning to embark on a quest for information and data regarding water in their southwest Napa County watershed. The Stewardship has been meeting since February 2001, to bring residents and other parties interested in the Carneros Creek watershed together to address resource concerns. One of the major concerns voiced by some of the residents and property managers in the area is the availability of water, both groundwater and surface water. Recognizing that very little information is available concerning the hydrology of the area, the Stewardship has developed two volunteer monitoring programs to bridge the information gap. Starting this year the Stewardship is monitoring wells in the area and installing a telemetric streamgage.
Working with the RCD, U.S. Geological Survey (USGS), Napa County Public Works and Richard Slade, Groundwater Consultant, the stewardship volunteers have worked tirelessly to develop a groundwater monitoring program, recruit volunteer wells, receive training and begin monitoring well levels. Well monitoring began in October, will occur again in the Spring and will continue for three to five years. “Gathering groundwater levels over a long time frame and large geographic area will provide the necessary facts to more accurately describe the groundwater level changes and groundwater flow directions in the Carneros Region,” says John Stewart of Napa County Public Works. Approximately 35 wells have been volunteered for monitoring and additional volunteer wells are being sought for the Spring. Many thanks to Chris Farrar of USGS, John Stewart of Napa County Public Works, Richard Slade and a number of landowners, whom without their volunteer assistance and dedication this program would not be possible.
Also on the horizon in the Carneros Creek watershed this winter is an effort to gather data about surface water flows and velocity. Coordinated by Lee Hudson and Blaine Jones, a number of individual landowners and managers have agreed to donate $10,500 to the RCD for installation and maintenance of a telemetric streamgage on Carneros Creek. The gage was installed in November and will likely begin to transmit water level data this month. For more information on streamgaging, see the related article on page 2.
Good things are happening in the Carneros Creek watershed (see related article on page 6 )! If you would like additional information on the Carneros Creek Stewardship, contact Leigh Sharp at 707/252-4188 or leigh@naparcd.org.
‘Tis the Season to Streamgage
Streamgaging is the process of measuring the discharge of a waterway at different water levels. The RCD maintains a network of streamgages throughout the Valleyto measure the volume rate of flow (or discharge) of the creek. This year the RCD will maintain a total of 6 streamgages (Napa Creek and Milliken Creek in Napa, Carneros Creek and Huichica Creek to the West, Hopper Creek in Yountville and Garnett Creek in Calistoga).
It is relatively easy to establish the water level of a creek. A pressure transducer can be installed beneath the bed of the stream, an ultrasonic streamgage can be installed on the underside of a bridge, or a graduated staff gage can be installed on a bridge pier. All can be used to measure the water level of the creek at any given time.
However, a record of a stream’s water level does not tell us much about how much water is actually flowing past a point at any given time. That’s where our “streamgaging” efforts come in. Throughout the rainy season, the RCD will dispatch staff members and trained volunteers to head out to the streamgaging sites to measure the stream’s velocity at various water levels. Once the average velocity of the stream is known, it is easy to calculate the discharge.
Streamgaging allows the RCD to match a river’s water level with an actual rate of flow (discharge) in the creek. Many creeks have automated gages, meaning the water level is reported to a data collector. By knowing the relationship between water level and discharge, we can then establish the total volume of the creek for an entire season or year.
Streamgaging involves using US Geological Survey equipment to measure the velocity of the stream in a number of stations across a channel. When water levels are low, this can be done by wading across the creek or river. When the streams rise to high levels (usually 2-3 feet), measurements are taken using suspension equipment from a bridge.
The RCD relies on volunteer support to maintain it’s many streamgaging sites. Granted, volunteers might get a little wet while streamgaging, but it can also be exciting doing fieldwork on swollen streams. Each streamgaging team is comprised of two people, one RCD staff member and one trained volunteer.
If you would like to get involved, the RCD will train volunteers in streamgaging protocol. Because of the unpredictability of large storm events, volunteers will be called-on during the winter and spring to assist RCD staff.
If you have questions, or would like to volunteer, please contact our hydrologist at (707) 252-4188.
NSWG to Publish
Sustainable Winegrowing Book in JanuaryIn January 2002, the Napa Sustainable Winegrowing Group (NSWG) will be publishing a book on sustainable farming methods practiced in the Napa Valley.
The book, entitled “Vineyards in the Watershed: Sustainable Winegrowing in Napa County.” is written for the public as well as grape growers and other people in the wine industry.
The book includes case studies of local farmers and information on Farming in a Watershed, Wildlife Protection, Integrated Pest Management (IPM), Water Quality, Vine Health, Stewardship efforts, Farm workers, Erosion Control, Weed Management, Cover Crops and Organic Farming.
The book will be made available through the Napa County Resource Conservation District. For more information on the book, contact Astrid C. Bock-Foster at the RCD at 252-4188.
WELCOME New Biologist!!
Please join us in welcoming the newest member of the RCD team. Jonathan Koehler has been hired as our Biologist. He most recently worked for the City of Livermore Water Resources Department and for Microsearch Environmental as a Biological Monitor. Jonathan has a Masters Degree from the University of California at Hayward. He will be working on many projects at the RCD including training volunteers for our watershed monitoring program. He brings with him a special love for fish and is especially interested in fisheries restoration. He can be reached at our office or by email at jonathan@naparcd.org.
Volunteers and Stewards
Make the Selby Creek Restoration Project a Success!A great couple of days were had by all who graciously participated in the bank revegetation phase of the Selby Creek Restoration & Enhancement Plan! On November 27 and 28, the RCD, in collaboration with local property owners, Larkmead Vineyards and the Shelton family, hosted a demonstration revegetation project on Selby Creek near Calistoga. Coordinated by Lara Hadhazy from the RCD and Ann Baker, landscape designer, and owner of Lifewise Terrain, and with the help of many dedicated volunteers, the project was a great success.
The final revegetation phase of this year’s CALFED restoration efforts included the planting of native vegetation around the perimeter of a quarter of an acre of open floodplain that borders the Larkmead vineyard and along the tops and sides of unvegetated or loose and eroding banks. The overall goal of the project was to enhance the riparian plant community and fish habitat along a stretch of the creek that borders Pierce’s Disease-inflicted Larkmead Vineyards on one side of the bank and the Shelton’s threatened residential homefront on the other. With the help of NRCS and RCD staff, bioengineering streambank stabilization plans were designed to address the issues of extensively eroding banks, lack of shade canopy, invasion by Himilayan blackberry, and the spread of Pierce’s Disease. These plans included in-stream measures such as 250 feet of willow revetments, extensive willow cuttings, numerous willow clusters, and four feet of willow/rock baffles. Many thanks to Bob Albers of NRCS and crews from Saviez and Madrigal Vineyard Managements, who completed the heavy construction and in-stream labor.
In addition to the goal of enhancing the riparian corridor along Selby Creek, a secondary goal of the project was to promote public awareness of stream ecology. As part of the community outreach component, productive and fun volunteer days began at 8 am and ended at 2 pm. In the morning, Lara and Ann presented an overview of the local watershed and other related key topics while volunteers enjoyed hot coffee. By the end of the two days, approximately 15 trees, 120 shrubs and smaller flowering plants, 1000 grass plugs, 50 acorns, and native seed were planted in various upper bank sites and along the terrace of Selby Creek where the previous in-stream bioengineering work was done earlier this fall. The 24 different native plant and grass types were carefully hand-selected by Ann Baker and, among other species, included valley oak, bay laurel, ceanothus, coyote bush, sticky monkeyflower, wild honeysuckle, yarrow, california poppy, and blue wild rye. The perfect combination of gorgeous weather, great teamwork, and delicious tomato soup, kindly donated by Alexis Baking Co., enticed several volunteers to come back for a second day!
Ultimately, the projects successful completion was made possible by the dedicated efforts of Larkmead Vineyards, the Sheltons, seven local volunteers and two students from the SRJC Watershed Restoration Class. The project was a great opportunity to share hands-on information on native plants of the riparian corridor, Pierce’s Disease, and habitat restoration techniques while restoring an important section of riparian habitat. Many thanks to all who were involved!
If anyone is interested in joining future volunteer restoration activities, please email lara@naparcd.org or call Lara Hadhazy at the RCD for more information.
Stewardship-based Watershed Assessments
on Sulphur and Carneros CreeksEveryone seems to know what our creeks and watersheds need. However, not all experts agree on what constitutes a healthy watershed. The RCD promotes a stewardship-based approach to watershed management, in which those with a stake in a watershed get together with their neighbors and, on the basis of shared interests, determine their own management goals. For the residents of two local creeks, this approach has led to a $360,000 CALFED grant to the RCD to assess their watersheds and write management plans that reflect the consensus of what these concerned local people want for their creek watersheds.
The Sulphur Creek Watershed Task Force and the Carneros Creek Stewardship, two grass-roots groups with a strong interest in taking care of their creek watersheds, have asked for more information on how their creeks work, in order to help them manage their use of the land. Their efforts will get a shot in the arm in early 2002, when work gets underway on the new CALFED-funded project. RCD technical staff, working in close collaboration with scientists from San Francisco Estuary Institute and other subcontractors, will thoroughly assess the physical condition of the stream channels and the contributing watersheds and write management plans to meet the needs expressed by the stewardship groups.
The Sulphur Creek group has existed for approximately two years and the Carneros group has existed since February of this year. Both groups have identified issues that they would like to see addressed and are strongly interested in a physical assessment of their respective watersheds. They want to utilize the results from the assessments to create management plans that provide specific strategies for improving the water quality and aquatic habitat. The results of assessment and planning will provide a framework for undertaking long-term restoration activities in an efficient, coordinated manner.
Field work in the two watersheds will last through the summer, and completion of the assessments and plans is slated for mid-2003. There will be a number of opportunities for volunteer involvement; check with the stewardship groups or call the RCD office for more information. Watch future newsletters for more detailed information on what’s going on in these two watersheds.
A Crash Course in Erosion
Erosion is the wearing away of the earth’s surface from forces brought to bear by the movement of wind, ice floes, or water. In Napa County, the most important kind of erosion is brought about by water. Water erosion, and the resulting sedimentation, are naturally occurring phenomena, intrinsic to the predictable patterns by which landscapes change over time. However, within timeframes relevant to human history, soil erosion tends to reach states of equilibrium with the processes of soil formation from parent material, influencing and being influenced by climate, topography, geology, and biological activity. It is in part upon this delicate equilibrium that the web of life, along with much of what we regard as “natural resources,” depends.
Over extended periods of geologic time, major influences such as climate change, glaciation, volcanic activity, and tectonic uplift may have catastrophic consequences for specific biological systems. We are beginning to understand that within a remarkably short period of time, human activities can also wreak havoc on biological systems. History and the archaeological record show that loss of agricultural soils and the siltation of waterways have played major roles in the decline of numerous civilizations. For this reason, a great deal of RCD and Natural Resources Conservation Service (NRCS) energy is devoted to recognizing and mitigating accelerated, human-induced soil erosion and sedimentation. Erosion is customarily quantified in terms of tons of soil loss per acre per year. Napa County soils typically regenerate themselves at a rate of from one to five tons per acre per year. For reference, a ton of soil may be visualized as the thickness of a sheet of paper spread over an acre.
There are, in general, four types of water erosion: sheet erosion, rill and gully erosion, streambank erosion, and mass wasting.
Sheet erosion , or splash erosion, occurs on the surface of the soil, when particles are displaced by the force of falling raindrops. Frequently not detected by the untrained eye, this type of erosion is nonetheless insidious and potentially damaging over time. Displaced particles can either move long distances from a site or be re-deposited nearby, as a function of rainfall intensity and duration, topography, and the density of the particles. Bare, newly disturbed soils may suffer sheet erosion at rates of up to 15 tons per acre per year. The best defense against excessive sheet erosion is a good vegetative cover crop. Cover crop establishment is frequently enhanced by applications of straw mulch, erosion control blankets, and/or irrigation to germinate seeds prior to the onset of heavy winter rains.
Rill and gully erosion begins to occur within a relatively short distance if sheet flows are allowed to build velocity over unprotected soil. These concentrated flows may lead to soil loss in excess of 300 tons per acre per year in the gullies themselves. Gully erosion is best prevented by minimizing sheet flows (again, with good vegetative cover). Where topography
and slope length make concentration of sheet flow inevitable, flows can be diverted to protected outfalls with underground pipes or gently sloping earthen, grass- or rock-lined ditches. Suitable outfalls may include well-vegetated natural waterways or filter strips, rock energy dissipators, level spreaders, and detention basins. Repair of existing gullies can be accomplished with either hard armor, grade control structures, or bio-engineered installations such as willow revetments and brush wattles. Restoration of native plant communities will frequently help prevent recurring problems in critical or badly-damaged areas.
Streambank erosion is also a natural phenomenon. Creeks and rivers in equilibrium are dynamic systems--moving and depositing predictable amounts of sediment; shifting; eroding; and meandering within definable, usually well-vegetated riparian belts. A river’s equilibrium is upset when changing land uses, such as road construction and urban and agricultural development, modify the hydrology of the streams watershed, frequently by reducing infiltration rates and increasing runoff rates and peak storm flows. These increased flow velocities in turn increase the erosive and destabilizing forces on streambanks. Incursion of intensive land uses onto floodplains and other portions of the riparian belt, combined with increased flow velocity, frequently lead to property damage. However, confining the river with levees to protect property within the flood plain or riparian belt, thus isolating the river from its floodplain, can exacerbate flooding, bank failures, and excess sedimentation downstream. Bank failures can be, and frequently are, addressed on a piecemeal, site-by-site basis with riprap emplacement or other hard-armor structures. These measures are frequently ineffective or short-lived, and nearly always have unintended side effects--both upstream and downstream. Long-term solutions to streambank instability must focus on re-establishing the river’s equilibrium, by modifying land use practices within the watershed to more nearly emulate the natural hydrology, and by allowing the river a sufficient riparian belt-width in which to resume normal fluvial function.
Landslides, or mass wasting are common in the southern hills (Jamison Canyon, Carneros) and Mayacamas Mountains (Mt. Veeder, Spring Mountain, Bear Creek Canyon) of Napa County, due to the inherent geologic instability of soils. This susceptibility to mass wasting is sometimes exacerbated by tree removal, overgrazing, and grading. A common, very expensive mistake is to grade away the toe of a temporarily stable slide with a road cut, destabilizing a large mass uphill. Once activated, a slide can be very difficult to repair and stabilize. An active slide is not only problematic for property owners, but also frequently a serious water quality threat, as a source of excess sediment in waterways. It is thus very important to be able to recognize ancient, dormant, and active slides, and to avoid them when possible. The County of Napa maintains geologic hazard maps, which are helpful in identifying specific significant landforms that may be unstable. Consultation with a geotechnical specialist or soils engineer is a must when contemplating any potentially invasive land use or development in an area subject to mass wasting.
Erosion and sedimentation are components of Napa County’s “balance of nature.” However, accelerated erosion and sediment delivery are threats, not only to the productive soil resources that have been the lifeblood of Napa County’s viticultural economy, but also to the watersheds and waterways that allow that economy to flourish within the greater community of functioning, biological systems. The community’s needs for economic expansion should be integrated into the needs of those systems. Part of that integration is controlling excess erosion and sedimentation.
Contact the Natural Resources Conservation Service (NRCS) or the Napa County Resource Conservation District for more information about erosion, practices to minimize erosion, and techniques used to restore sites that are eroding. Technical and financial assistance may be available.
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