Napa River Watershed Owner's Manual
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Section II: Recommendations by Objective:
- Promote stream stabilization using natural processes
- Promote contiguous habitats
- Increase biological diversity
- Increase migratory and resident fish habitat
- Encourage land stewardship
- Coordinate natural resource protection and planning efforts
- Reduce soil erosion
- Promote sustainable land use concepts
- Promote and improve water management
Background
Since the Gold Rush in California, it has been common practice to alter stream drainages to accomplish certain specific tasks. Because the changes have occurred for the most part in small increments, the cumulative effects of our river management and use have not always been clearly understood. Typically, alterations include straightening the channel; hardening the banks; changing the point of discharge; increasing or decreasing available flow; and separating the stream from its flood plain by the use of levees or floodwalls. Although such changes are appropriate in some cases, extensive historical and analytical work since the mid-1960's has shown that the degree of maintenance to sustain these altered systems, and the rate of failure of the alterations, is much higher than originally anticipated when the designs were installed. The 1993 floods in the Mississippi River drainage demonstrated very convincingly that many of our standard methods of stream management cannot be economically sustained over a long period of time.
Human development has greatly changed the natural systems of the Napa River. In the Napa Valley, most streams have been altered since 1800, either directly or indirectly (or both). Sloughs have been straightened, levees have been built, development of all types has occurred near streams and in their floodplains, and an estimated 6,500 acres of historical valley floor wetlands have been drained or filled. The past 150 years have seen native perennial grasses supplanted in many areas by introduced annual grasses; the original forests have been harvested; approximately 19,700 acres of the watershed are now under hardened pavement or rooftops; and another 26,000 acres have been developed to intensive cultivated agriculture. These alterations have changed the way the watershed works, and need to be accommodated in a new equilibrium that will preserve the watershed resources. One result of human activities is increased high peak storm flows during the winter, which decreases the amount of stream flow between storms and through the summer months.
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Stream Dynamics
The dynamics of many Napa Valley stream systems are now out of equilibrium with the amount and timing of rainfall runoff from watershed lands. One typical result of the disequilibrium is an "incised stream," or a stream whose channel has cut so deeply into its floodplain that it is considered to have abandoned the flood plain altogether. Without a floodplain, a stream must discharge a large amount of water in a much smaller cross section, thus increasing the velocity of the water. This increased velocity generates more energy in the stream system, which is frequently balanced by adding sediment to the stream to absorb the excess energy. That sediment is from the banks and bottom of the channel, resulting in bank and levee failure, and further down-cutting of the channel itself.
Increasing water velocity of a stream in excess of its stable level has other effects beyond increased bank failure and sediment production. The higher level of sediment transport also means that pollutants entrained in the sediment become more widely distributed. In addition, when discharge does overtop the banks of a stream, flood damage may be considerably increased, owing to the increased energy of the stream. Lateral migration of a stream which is attempting to decrease its gradient by re-establishing meanders is responsible for many acres of farmland lost, and for very high maintenance costs in urban areas for development directly adjacent to the stream channel. Straightening or hardening of the banks of a portion of a stream usually simply moves the problem upstream or downstream, but does not truly stabilize it. Development of a balanced stream system greatly reduces maintenance costs and adds value to the properties in the system.
Traditional stream work for the past several decades addressed only one issue at a time. Usually, stream alteration was done for flood hazard reduction, and relied heavily on engineered mechanical channels based on straight, clean channel models. Maintenance of these projects is particularly high, and other aspects of the river system, such as vegetated riparian corridors, wetlands, public recreation and geomorphologic stability were left out of the final product. Wildlife enhancement projects frequently focused only on wildlife, and did not consider flood threat impacts of the enhancement work. Drainage work for urban or agricultural uses often did not consider either flood control or wildlife in their design and construction. A multi-objective approach to river development and enhancement includes all these factors and seeks to recreate a sustainable river system that requires much less long term maintenance and provides a far greater range of benefits. By anticipating and utilizing the natural energy of the river or stream, a complete design may be developed that gives equal weight to flood hazard reduction; economic uses such as agriculture; aesthetic and recreational value; and environmental concerns. It necessarily also involves the participation of a much wider range of interests and skills, including technical, biological and community interests.
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Multi-Objective Planning
Because a multi-objective river corridor management plan includes a greater variety of interests and concerns, it must also include a more complex data base. To answer this need, a computer model of the Napa river is under construction at the Napa County Resource Conservation District. The model will present hydrologic flow data; sediment delivery effects; stream geomorphology; rainfall/runoff relationships; vegetation effects on river flow and form; channel form; and many other factors that affect the final function of the river system. These factors are then modeled with the aid of a complex computer program to help determine the most effective and economical design to achieve stream stability while addressing a broader range of interests than traditional river design. The model will be used to help plan the location and type of practice best used to stabilize the system, and will be a valuable asset in monitoring and evaluation of the watershed.
The following recommendations are to help stabilize the streams of the Napa River system:
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Streamside vegetated buffer strip
A1. Establish and maintain streamside buffer strips, both at individual sites and along streams through contiguous properties. Vegetated buffer strips alongside waterways help stabilize stream banks; reduce sedimentation and introduction of pollutants into the stream by filtering runoff; provide valuable biological diversity of plant and animal species; decrease ambient summer water temperatures; decrease storm runoff peaks by increasing rainfall infiltration into the soil; increase between-storm stream flows through greater stream recharge; and provide valuable wildlife habitat throughout the year.
| A1.1.
| Provide tree cover (late successional plant communities) along streams to shade the stream, to decrease in-stream growth of vegetation (such as willows and tules) that may block flow in wet months; decrease water temperature; decrease evaporative losses of water; decrease algal bloom and subsequent eutrophication in dry months; and increase property values.
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| A1.2.
| Use native varieties of plants, or plants whose functions are equivalent to those developed in arid, hot summer, wet winter climates to revegetate riparian buffer zones.
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| A1.3.
| Enhance riparian cover that is contiguous across property lines to increase both wildlife habitat and real estate values.
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| A1.4.
| Utilize stream side areas for open space and parks in urban developments. Large developments should be designed to enhance and emphasize any natural riparian zones in the project.
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A2. Promote regional park areas to reduce random access to the river, while controlling access (including trespass) to non-managed areas. River and stream riparian zones do not naturally accommodate heavy traffic without damage. Unmanaged trails down riverbanks, for instance, frequently become concentrated water courses during the rainy season, accelerating bank erosion and collapse. By designating specific areas for public access for recreation, those areas can be specifically developed and maintained to withstand concentrated traffic.
| A2.1.
| Easily accessible public areas that are managed specifically for public recreation should be established, with protected areas for direct access to the river. The areas should be constructed and maintained to allow river and riparian use without unnecessary damage to the system.
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| A2.2.
| Provide a wide range of publicly accessible recreational experiences and environments, in order to minimize pressure on private property and unmanaged areas.
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| A2.3.
| Establish the use of signs and/or other passive deterrents to curtail trespass on private property, or unmanaged access to public property in areas not designed for public use. An educational outreach effort should be ongoing that describes the reasons for not allowing unrestricted access to portions of the Napa River and its tributaries.
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| A2.4.
| Encourage golf courses, parks, and other public and private recreation areas to protect the streams through those properties by shielding them from direct access except in areas designed for access.
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A3. Promote streambank stabilization. One of the first noticeable effects of an unstable stream is the collapse or erosion of streambanks. Unstable banks are usually a symptom of other, less obvious problems, and repair of the failing bank does not often address the cause of the instability. Because streams are complex systems, altering one aspect of the system can have significant impacts on other aspects of the same system. Streambank repair and stabilization should always be done with careful planning and full awareness of the nature of the stream dynamics.
| A3.1.
| Flood control channels should be kept in functioning condition. Where possible, tree cover on channel banks should be used to control in-channel growth of vegetation.
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| A3.2.
| Provide streams with access to their flood plains where possible. Where streams are heavily incised, flood plains should be redeveloped beside the new channel at the new, lower elevation.
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| A3.3.
| Stream restoration should be done using techniques similar to those developed by Leopold, Rosgen, et. al. (see Bibliography and Appendices). Where possible and technically appropriate, redesign straightened reaches of stream and drainage channels using the same techniques.
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| A3.4.
| Control or eliminate livestock access to streamside areas by providing alternate, dispersed watering sites; fencing; or other practices associated with a managed grazing program. Protect livestock stream crossings and lake access points to minimize bank degradation at those sites.
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| A3.5.
| Streamside vegetation is an effective and inexpensive bank stabilization system, and should be the method of first choice in stabilization designs.
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| A3.6.
| Limit stream bank disturbing activities (such as utility installation) to the minimum amount necessary. Revegetate all disturbed areas as soon as practicable.
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| A3.7.
| Limit boat speeds in the estuary or near lake shores to protect against bank erosion from boat wakes.
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| A3.8.
| Develop shoreline wetlands to diminish bank erosion along waterways, ponds and lakes.
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| A3.9.
| Remove unnecessary man made channel barriers and weirs, which frequently cause bank and channel collapse laterally from the blockage.
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| A3.10.
| Register and upgrade illegal or non-permitted water diversions.
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A4. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| A4.1.
| Conduct demonstrations and tours of stream management sites.
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| A4.2.
| Provide a method of delivering regular public training sessions for urban, suburban, and rural stream repair and maintenance.
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| A4.3.
| Utilize technical assistance from the UC Cooperative Extension Service and the USDA Natural Resource Conservation Service for grazing management planning and implementation.
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| A4.4.
| Utilize stream restoration design assistance from the USDA Natural Resource Conservation Service, and from the California Department of Fish and Game, and other local agencies.
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| A4.5.
| Establish a watershed team to classify all tributaries of the Napa River using Rosgen methods. Assess habitat values and stream stability by reach for use as baseline status for trends analysis.
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| A4.6.
| Begin a program of vegetation and geomorphic mapping of the Napa River and its tributaries.
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| A4.7.
| Utilize actual restoration sites for the field elements of the Napa Schools curriculum.
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| A4.8.
| Provide bilingual education activities for stream restoration techniques.
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| A4.9.
| Employ the monitoring protocols developed for Riparian Stations to track stability trends in streams of the watershed.
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Background
Development of the Napa Valley has been markedly accelerated in the last 40 years, compared to the previous 100 years. The development has been incremental, and many of the watershed habitats of Napa River tributaries and the habitat along the River itself, have been gradually fragmented. Many historical migration corridors for wildlife have been segmented, and flyways for migratory birds now have widely differing characteristics along the flight paths. Site planning for individual projects or management plans have traditionally been done for the specific site only, and the recognition of the role the site may play in a larger natural system has not been part of the usual plan. Environmental benefits can be multiplied several-fold when planning is done with a watershed perspective in mind. Minor changes or additions in projects and plans can have significant impact when done in concert with neighboring parcels, and more complete natural systems are allowed to function.
The wildlife and biodiversity benefits of habitat enhancement are multiplied several fold when adjoining parcels can connect areas of habitat improvement. This is most pronounced when owners of contiguous parcels along a stream or in adjacent watershed ridgelines and headwaters, work together to create linear habitat along the stream or ridge through a series of adjacent parcels. Adjoining corners of parcels frequently offer the opportunity to jointly create habitat areas that can also be used for recreation by the parcel owners.
Benefits of these more efficient habitat areas include recreation; increased water infiltration into the soil; increased biological diversity and subsequent potential decrease in biological pests; and increased property values. They also help to maintain much of the natural uniqueness of Napa Valley and contribute to an improvement in the general quality of life for residents of the Valley. Implementation of the following recommendations will help improve and expand healthy wildlife habitat for the watershed:
B1. Reforest, afforest, and revegetate. One of the more significant cumulative changes in the watershed is diminished forest cover. The change has been not only in the total extent of cover, but in the spatial distribution of the remaining habitat, and the diversity within it.
| B1.1.
| Reforest areas to the maximum extent feasible with native trees, shrubs, forbs and grasses, using seeds collected from the local area. Using local seed sources preserves the unique genetics of neighborhood species and guards against outbreaks of disease or insect infestation to which only local plants may be resistant.
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| B1.2.
| Manage existing ponds and watercourses as wildlife habitat
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| B1.3.
| Enhance, restore, or rehabilitate wetlands in the watershed
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| B1.4.
| Enhance habitat value of artificial drainage ditches with plantings on the ditch banks
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| B1.5.
| Increase the use of hedgerows along field and property lines to provide migration areas for birds and small mammals.
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| B1.6.
| Where possible, develop contiguous habitats to include transition zones from one type of habitat to another, i.e.: riparian zone to gallery forest to upland.
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B2. Maintain corridors between open spaces. Establishment of wildlife corridors between existing open spaces encourages wildlife diversity and density. The connecting corridors also add to property values of those properties containing the corridors, and those adjacent to the corridors.
| B2.1.
| Evaluate and promote intercity green belts on public land and/or with the participation of the Napa County Land Trust.
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| B2.2.
| Encourage coordinated riparian enhancement along Napa River's tributary streams.
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| B2.3.
| Encourage development of contiguous east-west habitat corridors across the Valley at several points through cooperative efforts of adjacent landowners.
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| B2.4.
| Promote voluntary individual parcel planning that will help to connect enhanced riparian corridors on the eastern and western edges of the Napa Marsh, especially in the Huichica, Carneros, Suscol, Sheehy, Fagan, and American Canyon Creek watersheds.
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| B2.5.
| Provide public technical assistance to help landowners enhance and maintain a riparian corridor along both banks of the Napa River from north to south.
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B3. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| B3.1.
| Encourage landowners in subwatersheds to cooperatively establish habitat goals for their regions, based on local interests.
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| B3.2.
| Develop locally specific monitoring by landowners to track habitat improvement in enhanced lands.
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| B3.3.
| Include species diversity counts in the monitoring portion of the Napa school curriculum developed by the Resource Conservation District.
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| B3.4.
| Conduct workshops and tours to demonstrate the effectiveness of cooperative habitat enhancement by landowners.
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| B3.5.
| Increase the availability and use of financial assistance in the watershed from State and Federal programs for habitat enhancement on private lands.
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| B3.6.
| Support the creation of partnerships between local, state and federal governments, and between government and private landowners for contiguous habitat development.
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| B3.7.
| Encourage the adoption and use of the Napa Schools curriculum developed by the RCD to emphasize the importance of entire natural systems, rather than isolated "specimen" habitats.
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| B3.8.
| Seek support funding from federal and state programs established to restore and enhance river systems and biological diversity.
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Background
As development has occurred throughout the country, the number and variety of natural plant and animal species has decreased. Potential results of decreasing biological diversity include a decline in natural productivity of the land as food chains are interrupted; a rise in disease as genetic pools are lost; and more frequent pest infestations as predator/prey relationships become unbalanced. To maintain a healthier system that is able to adjust to fluctuating climatic conditions, an effort should be made to increase natural biological diversity in the watershed. The issue is particularly sensitive in the Napa River watershed, because the basin is uniquely centered at the transition crossroads of both major north-south and east-west biological regions. The Napa Valley represents the eastern-most habitat for Coastal Redwood, and the intermixing zone for Coastal and Interior live oak, for example. It is also the most significant southern range for the Spotted owl, and the most northern extension of San Francisco Bay wetland habitats.
The unique nature of the biological resource of the Napa Valley should be protected and enhanced by:
C1. Reforestation and afforestation. Diminished forest cover and fragmentation of remaining forested areas decreases biological diversity in a watershed. Increasing forested areas and connecting those areas through enhanced corridors will greatly increase the productivity of the habitats.
| C1.1.
| Encourage the enhancement and expansion of oak woodlands and oak grasslands:
- provide protection for selected volunteer oak seedlings.
- plant new trees from acorns collected from a nearby site in areas that have no natural regeneration.
- fence or otherwise protect areas of oak regeneration until seedlings are above grazing height.
- plant appropriate companion species to increase the diversity of existing oak habitats.
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| C1.2.
| Use material collected from as close to the planting site as practicable, in order to maintain biological integrity of the many different genetic variations of the watershed.
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| C1.3.
| Restore riparian zone functions along watershed streams, including streamside buffer strips.
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| C1.4.
| Enhance transition areas between habitat types to promote greater diversity of habitat.
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| C1.5.
| Enhance riparian cover that is contiguous across property lines to increase both wildlife habitat and property values.
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| C1.6.
| Plant native trees in unused areas of agricultural lands, including farm roadsides.
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| C1.7.
| Strengthen tree planting efforts in urban areas.
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| C1.8.
| Encourage greater use of native trees in industrial development.
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| C1.9.
| Reforest edges of flood and drainage channels to shade the channels.
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| C1.10.
| Plant trees in median strips and along public roadsides and rights of way.
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| C1.11.
| Encourage coordinated riparian enhancement along Napa River's tributary streams.
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C2. Enhance and expand wetland habitat. Wetlands are critical parts of any watershed, and are nearly equivalent to tropical rainforests in biological productivity. Wetlands are the beginning of complex food chains, and they provide other indirect benefits that encourage development of biodiversity in a watershed. Water filtration, sediment retention, flood attenuation are some of the indirect benefits of wetlands.
| C2.1.
| Enhance and expand seasonal freshwater wetlands, including riparian wetlands.
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| C2.2.
| Manage existing ponds, lakes, and streams as wildlife habitat.
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| C2.3.
| Include riparian wetland enhancement in floodplains when designing stream restoration and repair.
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| C2.4.
| Utilize the San Francisco Estuary Institute Regional Wetland Habitat Goals to help in planning the distribution and restoration of different types of wetlands (tidal, brackish, fresh and seasonal).
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| C2.5.
| Form a community partnership of diverse interests to provide assistance to the California Department of Fish and Game with the restoration of the Cargill salt ponds, and to participate in the North Bay Initiative planning effort for the Napa Marsh.
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| C2.6.
| Support the wetland education program incorporated into the Napa school curriculum developed by the Resource Conservation District.
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| C2.7.
| Form a coalition team to assess the present status of wetlands in the watershed, for inclusion in the GIS database for trends analysis.
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| C2.8.
| Establish trials in the watershed to determine the feasibility of using constructed wetlands as part of waste water treatment for non-consumptive purposes.
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C3. Reduce pesticide and fertilizer use...Both urban and rural pesticide and fertilizer use can present threats to biodiversity in a watershed when improperly used. They can also be beneficial tools when appropriately used. Development and use of alternative methods of pest and nutrition management can lessen cumulative negative impacts on watershed biodiversity.
| C3.1.
| Use Integrated Pest Management in agricultural areas, commercial landscaping, and private home maintenance.
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| C3.2.
| Develop and use pest computer models using California Irrigation Management Information System (CIMIS) data from the three Napa Valley CIMIS stations.
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| C3.3.
| Develop and use low-input management plans for golf courses, sports fields, cemeteries, parks, and other public areas.
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| C3.4.
| Provide regular educational programs for homeowners in proper use of fertilizers and pesticides around the home.
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| C3.5.
| Continue extensive investigation into the use of both permanent and annual vineyard cover crops for soil nutrition management.
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| C3.6.
| Revegetate annual grassland with native perennial grasses to reduce infestation of exotic weed species such as star thistle.
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| C3.7.
| Plant roadsides with perennial grasses and mow road shoulders and median strips in place of complete vegetation removal.
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| C3.8.
| Support the continued trial and use of natural predator insects for control of noxious weed species.
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C4. Promote regional park areas to reduce random access to sensitive areas of the watershed, while controlling access (including trespass) to non-managed areas. Sensitive habitat areas such as river and stream riparian zones do not naturally accommodate heavy traffic without damage. The biological functions and productivity of the areas may be impaired by excess traffic or unsuitable human activities. By designating specific areas for public access for recreation, those areas can be specifically developed and maintained to withstand concentrated traffic.
| C4.1.
| Provide a wide range of publicly accessible recreational experiences and environments, in order to minimize pressure on sensitive habitats, private property, and unmanaged areas.
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| C4.2.
| An educational outreach effort should be ongoing that describes the reasons for not allowing unrestricted access to portions of the Napa River and its tributaries.
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| C4.3.
| Encourage golf courses, parks, and other public and private recreation areas to protect the streams through those properties by shielding them from direct access except in areas designed for access.
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C5. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| C5.1.
| Establish Riparian Stations in the watershed to serve as data collection points for volunteer citizen watershed monitors.
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| C5.2.
| Develop and regularly publish a "biodiversity index" for public distribution, based on monitoring data from the Riparian Stations. The index will allow long term public observation of biological trends in the watershed.
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| C5.3.
| Support the use throughout the watershed of the Napa County Resource Conservation District school curriculum, including the Adopt-a-Watershed program and biodiversity monitoring system.
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Background
A major indicator of the health of a river and its drainage system is the condition of its fish and other aquatic resources. Migratory fish such as steelhead trout and salmon are highly sensitive to unstable systems. Decreases in water quantity or quality, and siltation of spawning beds results in rapid decreases in fish numbers. An increase in fish numbers and species diversity, however, is indicative of a healthy system whose parts are working well in concert with one another. The Napa River has seen the extirpation of its native Silver salmon run in recent decades, and other species are in serious decline. They are not the only fish species affected by the condition of the watershed, however. Other estuarine species also are sensitive to changes to siltation patterns and vegetation, and rely on a stable estuary to provide spawning grounds and protection from predators. Water temperature; water availability; food sources; salinity levels; water clarity; and many other factors determine the ability of fish populations to thrive. In a very direct way, the status of migratory and resident fish habitat tells a great deal about the condition of the watershed. Thus, fish habitat quality and quantity is a reflection of the cumulative results of land use practices in the entire watershed. Healthy habitat increases recreational possibilities as well, and helps support the complex chain of aquatic food supply.
Migratory and resident fish habitat may be increased in two ways. The first is by improving the condition of existing habitat, thereby allowing greater and more diverse populations of fish to survive. The second is by expanding habitat to include areas not presently capable of supporting fish. Restoration of the Cargill salt ponds in the Napa Marsh is an example of habitat expansion. Some recommendations for increasing migratory and resident fish habitat include:
D1. Increase habitat quality. One way to increase fish habitat is to make existing habitat more productive by increasing the quality of the habitat.
| D1.1.
| Manage urban storm water runoff to protect the quality of receiving waters: (See "L: Residential Land Use" and "M: Commercial, Industrial and Public Institutions" for more recommendations).
a) stencil storm drains to alert residents to the direct inflow to the river from the drains
b) sweep, rather than wash, paved areas to collect pollutants before they enter the river system
c) encourage the use of permeable materials for parking lots, walkways, etc.
d) direct storm gutter outlets underground to provide percolation of rainwater through the soil.
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| D1.2.
| Landscape maintenance debris such as grass clippings and leaves should be composted and recycled in areas away from riparian zones.
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| D1.3.
| Implement practices that will control erosion and subsequent sedimentation from agricultural areas. (for more recommendations, see "G: Reduce Soil Erosion" Objective, and "J: Agricultural" Land Use).
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| D1.4.
| Manage public access areas to restrict traffic impacts to small controlled and protected areas.
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| D1.5.
| Establish streamside buffer strips to filter runoff and provide shade.
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| D1.6.
| Provide off stream watering areas for livestock.
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| D1.7.
| Filter runoff from confined animal facilities, including small horse pastures.
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| D1.8.
| Regularly inspect on site waste disposal systems (leach fields) to ensure proper functioning.
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| D1.9.
| Parks, golf courses, cemeteries and playing fields should adopt low pesticide and fertilizer use management techniques to eliminate tainted runoff into drainages.
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| D1.10.
| Carefully measure all pesticides and fertilizers before use and follow label instructions for application, storage, and disposal.
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Reference: Western Shasta Resource Conservation District
D2. Increase habitat quantity. A second means to increase fish habitat is to increase its spatial extent by construction of new habitat, or restoration of lost habitat.
| D2.1.
| Instream structures should be altered where necessary to facilitate upstream migration of fish in order to provide access to more extensive spawning areas.
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| D2.2.
| New instream structures should be built if necessary to allow upstream migration of fish. The floodplains of the river and its tributaries should be converted to appropriate wetland habitat where economically and scientifically feasible.
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| D2.3.
| Use of wetland filters for dispersal of treated wastewater should be developed where appropriate.
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| D2.4.
| Provide shading with riparian tree cover in presently unshaded reaches of the river and tributaries, in order to allow areas to become useable by fish.
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| D2.5.
| New developments should utilize riparian areas as enhanced amenities, rather than as separated drainage channels as part of their open space development.
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| D2.6.
| Where possible without increasing flood threat, flood control channel banks and drainage ditches should be vegetated to decrease evaporation and water temperature.
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D3. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| D3.1.
| Increase public awareness of the status and importance of fishery health through news releases, articles, public speaking opportunities, and educational material distribution.
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| D3.2.
| Assist the California Department of Fish and Game with salmonid inventories in the watershed, and publish the results in local news media.
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| D3.3.
| Promote the establishment of local land stewardships in the subwatersheds, with special emphasis on salmonid habitat enhancement.
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| D3.4.
| Include fish species data and habitat health assessments in the monitoring programs of the Riparian Stations.
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| D3.5.
| Promote the use of small aquaria and live native fisheries in bilingual school classroom units.
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| D3.6.
| Coordinate a common water quality monitoring network in the watershed.
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| D3.7.
| Monitor gravel spawning bed status in stream channels:
a) for excess sediment
b)for insufficient gravel (such as below impoundments)
c)for adequate gravel size distribution
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Background
One of the outcomes of growth and an increasingly complex community in the County has been the lessening of coordination and communication amongst agencies, municipalities, citizen organizations and trade groups operating in the watershed. While the activities, requirements, regulations and programs of each have been established for similar purposes, the procedures of each differ from one another. The confusion inherent in separate or isolated development of resource protection efforts creates inefficiency for both private citizens and government alike. Because the desired results of each of the protection efforts are similar, coordination of the procedures to implement them should be streamlined. The resulting clarity would enhance resource protection efforts considerably, while also decreasing their cost.
The incremental nature of community growth, and the spatial separation of communities in the Napa River watershed have resulted in a set of resource protection planning and regulatory tools that are not always closely aligned with neighboring entities. The following recommendations are to encourage greater coordination of natural resource protection and enhancement in the Napa River watershed.
E1. Provide a continuing forum for information and technology exchange amongst the private and public sectors. Regular information exchange is an important element of coordination of resource conservation efforts. Open communication can provide a means to relate concerns, interests and issues among the community.
| E1.1.
| Establish an ad hoc Inter-Agency County-wide task force to help coordinate natural resource protection planning and regulation.
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| E1.2.
| Establish an information sharing method to allow coordination and mutual assistance for County, municipal, and other public entities to develop and manage required National Pollutant Discharge Elimination System (NPDES) permits in the watershed.
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| E1.3.
| Provide access to the coordinated NPDES permit plans to private entities for use in development of project based NPDES permits.
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| E1.4.
| Establish an informal consultation among municipalities and the County to discuss coordination of General Plan language.
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| E1.5.
| Provide continuing informal exchange among local government; agricultural; development; and construction trade representatives to help develop consistency and effectiveness of existing regulatory programs.
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| E1.6.
| Utilize cooperative planning to concentrate improvements in presently developed areas to protect agricultural uses and open space lands and minimize new habitat disturbance.
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| E1.7.
| Provide frequent opportunities for agricultural and environmental interests to work with urban planners to find creative ways to enhance developed areas and lessen development pressure on open space and agricultural lands
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E2. Participate in regional programs for environmental enhancement. The Napa River is one of the largest streams inside the Carquinez Strait that feeds the San Francisco Bay system. The river watershed has a significant impact on San Pablo Bay, and is affected in turn by conditions in San Pablo Bay and in Carquinez Strait. Participation in regional efforts to enhance the entire Bay-Delta system will contribute toward establishing a healthy watershed in the Napa Valley.
| E2.1.
| Assess County and Municipal programs to determine the degree to which they do or can support implementation of the Comprehensive Conservation and Management Plan for the San Francisco Bay Estuary.
|
| E2.2.
| Provide formal and informal opportunities for local government and local citizens to participate in restoration of the Cargill salt ponds in the Napa Marsh.
|
| E2.3.
| Encourage coordination of planning efforts and programs such as the State Lands Carquinez Plan, the North Bay Initiative, the Napa County Resource Management Plan for the lower Napa River, the Napa River Flood Control Project, and restoration and redevelopment plans for Mare Island.
|
| E2.4.
| Work to establish continuity and standardization of watershed monitoring protocols to generate monitoring data that can be widely utilized, including use with the Regional Monitoring Strategy currently being developed for San Francisco Bay.
|
| E2.5.
| Encourage regulators to utilize the Riparian Station monitoring protocols when requiring monitoring as part of permit issuance or mitigation, in order to increase available data for the GIS.
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E3. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| E3.1.
| Promote necessary changes to federal, state, and local regulations to encourage voluntary wetland and wildlife area restoration on private lands.
|
| E3.2.
| Establish a minimum of two Riparian Stations in the Valley to collect and sort watershed monitoring data.
|
| E3.3.
| Establish a central data base for obtaining information regarding all natural resource protection regulations that pertain to activities in the Napa Valley. The information should be publicly available for data base search for specific proposed actions or projects in the watershed, and cooperatively maintained in a timely manner to reflect changes in regulations as they occur.
|
| E3.4.
| Provide regular workshops for landowners, agencies and project managers that include explanation of permit and other regulatory processes of local, state and federal governments
|
| E3.5.
| Encourage the integration of existing restoration and enhancement projects with implementation of the Napa School curriculum developed by the RCD.
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Background
By considering long term effects of land use decisions, a community can avoid or minimize possible negative environmental results of those actions. To retain a long term perspective, however, requires education about the natural system in which we live and work. Most of the recommendations in this section are to provide more access to information to assist land users and managers in making decisions about how the land is to be used. By having educational and technical assistance readily available, land managers can reasonably and effectively implement practices that will enhance and protect natural resources for generations yet to come.
The purpose of land stewardship is to protect and enhance natural resources in order to maintain the long term integrity of the land.
F1. Encourage partnerships, alliances, and cooperation between and among groups. Sharing interests and concerns on a regular basis can result in positive community building. Regular efforts to communicate interests promote greater creativity in planning and more flexibility in management options for watershed protection.
| F1.1.
| Foster private/public partnerships with agencies and groups such as local chapters of national and regional organizations; local public interest groups; trade associations; school district support organizations; and individuals.
|
| F1.2.
| Promote greater interaction between agriculture, development, government and environmental groups through community meetings and forums.
|
| F1.3.
| Provide greater opportunities for interaction of business and agricultural interests with Napa Valley schools through regular program curricula.
|
| F1.4.
| Provide a central "clearing house" for information about management options and existing programs that can assist citizens and organizations in watershed enhancement efforts.
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F2. Establish subwatershed stewardships. Local community-based protection and enhancement efforts allow development of watershed protection and enhancement that more appropriately suits the needs and abilities of residents.
| F2.1.
| Seek assistance and funding to help establish local stewardships for each of the major tributaries to the Napa River.
|
| F2.2.
| Provide assistance to urban neighborhoods to establish stewardship programs with emphasis on urban streams.
|
| F2.3.
| Encourage the establishment of appellation based stewardship programs for grape growers and wineries in the grape growing areas of the Valley.
|
| F2.4.
| Establish an incentive program to publicly recognize successful local watershed stewardship enterprise.
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Adapted from Silviculture Treatments, General Technical Report, PNW-134, USDA, F. S., 1982.
F3. Provide a continuing forum for information exchange amongst the private and public sectors. Regular information exchange is an important element of successful stewardship of natural resources. Open communication can provide a means to relate concerns, interests and issues among the community and helps promote creativity in planning and management.
| F3.1.
| Establish an ad hoc Inter-Agency County-wide task force to help coordinate natural resource protection planning and regulation.
|
| F3.2.
| Establish an informal consultation among municipalities and the County to discuss coordination of General Plan language.
|
| F3.3.
| Provide continuing informal exchange among local government; agricultural; development; and construction trade representatives to help develop consistency, effectiveness and appropriateness of existing regulatory programs.
|
| F3.4.
| Utilize cooperative planning to concentrate improvements in presently developed areas to protect agricultural uses and open space lands and minimize new habitat disturbance.
|
| F3.5.
| Provide frequent opportunities for agricultural and environmental interests to work with urban planners to find creative ways to enhance developed areas and lessen development pressure on open space and agricultural lands
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F4. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| F4.1.
| Hold regular stewardship watershed planning workshops for Napa Valley residents.
|
| F4.2.
| Establish a stewardship newsletter to provide a means of information and idea exchange for local stewardship groups.
|
| F4.3.
| Make monitoring data available to all stewardship groups for use in local planning and management.
|
| F4.4.
| Provide an annual Resource Conservation forum and Fair for technical education and information exchange.
|
| F4.5.
| Support the Napa School curriculum developed by the RCD to encourage development of a stewardship land ethic for watershed management.
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Background
Soil erosion is a naturally occurring process that is easily accelerated by human activities. The Napa River watershed is naturally a relatively high producer of sediment owing to its climate, topography, geology and soil conditions. This natural production of sediment has been accelerated by human activities of the past 150 years. The sensitivity of the watershed to soil erosion amplifies the need for sound land management practices that minimize the loss of soil into the river and San Pablo Bay.
Three major types of erosion occur in the watershed:
Sheet and rill erosion, which represents a more or less even layer of soil removal over large areas, is rarely recognized as a significant drain on natural resources, because it is not visually spectacular at any given site. Most soils in the Napa River watershed form naturally at the rate of approximately 1 to 4 tons per acre per year. Sheet and rill erosion can remove up to 10 tons per acre per year without highly visible effects. Small concentrated water flows that are the beginning of gullies usually become apparent only when the rate exceeds 20 tons per acre per year.
Streambank and gully erosion, is another type of soil loss that is generally caused by concentrated water flows that are not in equilibrium with their channels. This type of erosion is more visually noticeable than sheet and rill erosion, and can represent 300 tons or more of soil loss per acre per year. It is found throughout the watershed, in both urban and rural areas. The systemic causes that creates this type of erosion are not usually as evident as the erosion itself, however. Land management practices; changes in hydrology; changes in rainfall infiltration rates; hardened surfaces; and inadvertent diversions are some of the non-natural causes of streambank and gully erosion.
Mass wasting, or landslide type activity is a third type of soil erosion that is found in many areas of the Napa Valley. There are many causes of this type of soil loss, including geologic instability, water holding characteristics of soils, and removal of tree cover. Some mass wasting takes the form of spectacular landslides, or debris flows, that can be several acres in extent, while others are less extensive, such as small slips along roadsides. Soil creep also occurs, where entire sections of hillsides slowly move downward. Leaning telephone poles and fenceposts are often the only indicators of this form of erosion. Mass wasting can be triggered by human activities such as road building, or house pad establishment, where the supporting toe of a slope is completely or partially removed, creating instability in the slopes above. Saturated leach fields, or improperly installed drains can also trigger mass wasting on hillslopes and streambanks.
In the Napa River watershed, two areas are particularly susceptible to mass wasting. The western hills from the City of Napa northward, particularly in the Mt. Veeder area, and the hills of southern Napa County are naturally less stable, and therefore more sensitive to alteration than other areas of the County.
Soil erosion and resulting sedimentation are among the most serious threats to the long term health of the Napa River system. The topsoil of Napa Valley is the wellspring from which its fame arises. Excess sediment in watershed streams represents not only loss of habitat and wildlife value, but a very real erosion of a basic asset that makes the Napa Valley a unique spot on earth.
G1. Reduce streambank instability and erosion. Streambank erosion is one of the most significant contributors of sediment to the Napa River. Simply repairing a failing bank, however will not usually cure the problem. Streambanks are part of a complex dynamic system of physical, chemical and biological energy, and will chronically fail when the system is not in equilibrium. The longest term solution to streambank instability is to reestablish stream equilibrium through careful analysis and planning.
| G1.1.
| Establish riparian buffer strips between developed land and stream channels.
|
| G1.2.
| Provide streams access to adequate floodplains wherever it is economically achievable.
|
| G1.3.
| Vegetate banks of existing streams with appropriate vegetation to maintain bank stability.
|
| G1.4.
| Increase rainfall infiltration and decrease peak storm runoff by:
a) reforestation and afforestation.
b) replacing annual grasses with perennial grasses.
c) decreasing the use of impermeable surfaces in the watershed.
d) using infiltration beds for runoff from paved and roofed surfaces.
|
| G1.5.
| Stream restoration should be done using techniques similar to those developed by Leopold, Rosgen, and others (see Bibliography and Appendices).
|
| G1.6.
| Control or eliminate livestock access to streamside areas by providing alternate, dispersed watering sites; exclusionary fencing; hedgerows; or other practices associated with a planned grazing system.
|
| G1.7.
| Limit stream bank disturbing activities such as utility installation and bridge construction to the minimum amount necessary, and revegetate disturbed areas promptly.
|
| G1.8.
| Develop or enhance shoreline wetlands to diminish bank erosion along waterways, ponds and lakes.
|
| G1.9.
| Remove unnecessary man made channel barriers and weirs, to forestall lateral stream movement and subsequent bank collapse.
|
| G1.10.
| Where possible and technically feasible, reestablish wetlands to filter storm runoff and attenuate flooding.
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G2. Reduce erosion resulting from agricultural activities. Agricultural activities in the Napa River watershed include grazing, viticulture, small farms and horticulture. Soil disturbance or vegetation removal as a result of agricultural activities can result in loss of topsoil and subsequent water quality degradation. Good agricultural management can also benefit water quality and wildlife habitat, and can contribute to the overall good health of the watershed. (Also see "J. Agriculture Land Use").
| G2.1.
| Emphasize erosion prevention over sediment retention as a priority in agricultural planning and operations.
|
| G2.2.
| Promote the use of permanent vegetative ground cover in vineyards. Support research, demonstrations and technology exchange to refine cover crop technology for vineyards and orchards.
|
| G2.3.
| Establish tree cover in unused areas to decrease erosion of topsoil.
|
| G2.4.
| Maintain access roads and farm roads to control stormwater runoff in agricultural areas. Utilize assistance from the USDA Natural Resource Conservation Service, or other erosion control professionals, for design of stormwater runoff control on rural roads.
|
| G2.5.
| Minimize wet weather vehicle traffic through or across agricultural areas, especially on hillsides.
|
| G2.6.
| Provide adequate energy dissipaters for culverts and other drainage pipe outlets.
|
| G2.7.
| Establish vegetated buffer strips along waterways.
|
| G2.8.
| Develop grazing management plans to increase vegetation residue on rangeland.
|
| G2.9.
| Exclude livestock from streams except in hardened, specially designed access areas, or develop grazing strategies that minimize negative impacts on streams.
|
| G2.10.
| Develop dispersed water supplies for livestock designed to decrease animal concentrations in small areas.
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G3. Reduce soil erosion resulting from urban and residential development. Non agricultural development is an increasingly significant source of soil erosion and sedimentation as the watershed population increases. Good planning and thoughtful development can avoid most negative impacts to the watershed of urban and residential construction and growth (Also see "L: Residential Land Use," and "M: Commercial, Industrial and Public Institutions).
| G3.1.
| Build close to existing functioning roadways to minimize negative environmental impacts from roadway expansion and extension.
|
| G3.2.
| Develop ways to re-use or redevelop existing structures before disturbing soil to build new ones.
|
| G3.3.
| Where possible and technically feasible, drain roof tops and paved areas into underground dispersal pipes or vegetated infiltration beds.
|
| G3.4.
| Increase the amount of permeable surfaces in urban areas to increase rainfall infiltration into the soil.
|
| G3.5.
| Revitalize and restore urban waterways as functional amenities, including utilization of buffer strips between the streams and developed areas.
|
| G3.6.
| Keep concentrated development away from sensitive areas such as riparian corridors and wetlands.
|
| G3.7.
| Roadways and drainage ditches should be managed and maintained to avoid sediment production and movement.
|
| G3.8.
| Replace herbicide and mechanical vegetation removal along roadsides with perennial grass mowing programs.
|
| G3.9.
| Revegetate, mulch, or otherwise protect disturbed areas at all construction sites as soon as possible after disturbance.
|
| G3.10.
| Establish temporary berms to contain wash waster and irrigation installation overflows on site in construction areas.
|
| G3.11.
| Increase the use of permeable surfaces to encourage infiltration of rainfall into the soil, and decrease peak storm runoff.
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G4. Minimize new road construction. One of the major sources of soil erosion, sediment production, and habitat loss in the watershed is roadways and fire breaks. Proper design and maintenance of watershed roads can eliminate thousands of tons of sediment from reaching the river each year.
| G4.1.
| Utilize joint access wherever possible to minimize roadways into rural parcels.
|
| G4.2.
| Erosion control and sediment reduction should be the highest priority in rural road design.
|
| G4.3.
| Utilize USDA Natural Resource Conservation Service assistance to design roadway maintenance systems and erosion control practices for existing roads.
|
| G4.4.
| Unpaved roads should have frequent waterbars or other storm water runoff controls, and controls should be kept in working order.
|
| G4.5.
| Abandoned roads should be removed and revegetated.
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G5. Manage public areas to minimize soil disturbance and threats of erosion. Trails, picnic areas, parking lot perimeters and roads all present possible erosion source sites in recreation areas.
| G5.1.
| Design trails with waterbars and other erosion prevention techniques, such as eliminating "crossover" access on switchback trails.
|
| G5.2.
| Maintain erosion control practices as a priority fall activity in public trail and other access areas.
|
| G5.3.
| Provide informational signs to inform the public of erosion hazards.
|
| G5.4.
| Control vehicle access to limit vehicles in unpaved areas.
|
| G5.5.
| Provide sediment control, mulching and reseeding for areas cleared by heavy foot traffic, such as picnic areas and meeting sites.
|
| G5.6.
| Carefully design trails to minimize damage from mountain bicycles and horse traffic.
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G6. Increase the use of erosion control techniques and practices for existing land uses. Awareness of the hazards of soil erosion is rising rapidly in the Napa River watershed. Techniques and practices to protect against erosion have are much more available and the technology much more advanced than when many of the existing uses were begun. Existing land uses with inadequate or non functional erosion control can frequently be protected through installation of one or more simple management practices. The cumulative impact of widespread use of erosion control practices is very significant, and could mean saving thousands of tons of virtually irreplaceable Napa Valley topsoil each year. The USDA Natural Resource Conservation Service is a primary source for erosion control advice and assistance.
| G6.1.
| Include erosion and sediment control as a priority when planning soil disturbing activities and projects in the watershed.
|
| G6.2.
| Use water diversion ditches, pipes, or structures on hillsides to shorten the length of slope that rainfall must travel before safe discharge into a stable pipe or channel.
|
| G6.3.
| Use storm drains and underground pipe to collect concentrated surface water flows and safely discharge into a stream or other receiving drainage.
|
| G6.4.
| Use straw or other fiber mulch to protect soil from erosion until a permanent vegetative cover is established.
|
| G6.5.
| Maintain permanent or annual waterbars in all unpaved roads, and direct them toward a protected ditch, pipe, or other appropriate conveyance for safe discharge.
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G7. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| G7.1.
| In cooperation with the Regional Water Quality Control Board, determine a method for long term tracking of sediment movement in the Napa River, both from the watershed and from San Pablo Bay.
|
| G7.2.
| Encourage local neighborhood land stewardship groups, especially in concert with the watershed programs of neighborhood schools.
|
| G7.3.
| Establish "watershed awareness" centers at local libraries to have readily available information about watershed protection activities and practices.
|
| G7.4.
| Locate sponsors for regular cooperative erosion control technical workshops in the watershed to include the Natural Resource Conservation Service, UC Cooperative Extension, RCD, trade organizations and other interested agencies and groups.
|
| G7.5.
| Increase the use of erosion control cost sharing programs such as those offered by the Agricultural Stabilization and Conservation Service.
|
| G7.6.
| Support the use throughout the watershed of the Napa County Resource Conservation District school curriculum.
|
| G7.7.
| Establish a network of representative monitoring sites to regularly assess erosion of stream banks; stream channels; agricultural areas, and public parklands in the watershed.
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Background
With a growing population and a fixed amount of land to live on, the way we use our land is growing more critical. There is no more West to which Horace Greeley sent the young man of the last century. We as a community must be certain that we utilize the natural resources we have in an intelligent manner that will keep the resource base intact for coming generations. It means thoughtful use and development of our watershed, and sensitive enjoyment of the natural assets of the Napa River system. These recommendations provide concepts and practices that promote the long term availability of the natural resource systems of the watershed.
The balance between urban growth and maintenance of the rural character of the Napa Valley is a dynamic balance. Thoughtful anticipation of the long range effects of short range decisions is crucial to achieving a balance that will allow maximum long term appreciation of the Valley's assets. Much of the attractiveness of the Napa Valley is its rural character, yet that attractiveness has the potential of self destruction if land management and land use are based on other than long term considerations. Sustainable land use concepts are those that consider the impact of land use decisions on the entire watershed system, and that promote consumption of resources at a rate that does not deplete them.
H1. Encourage long term coordinated planning between Municipalities and County governments. As the municipal areas of Napa Valley expand, coordination of planning becomes more necessary. Protecting our natural resource base is best done through farsighted combined efforts of the entire watershed community.
| H1.1.
| Establish an inter-agency group to recommend ways of increasing coordination of planning activities and increasing communication between planning agents in the watershed.
|
| H1.2.
| Provide a method that includes informal, interest-based public participation in coordination of planning efforts by local governments, including General Plan development (see Coordinate Natural Resource Protection and Planning objective).
|
| H1.3.
| Utilize cooperative planning to concentrate improvements in presently developed areas to protect agricultural uses and open space lands and minimize new habitat disturbance.
|
| H1.4.
| Provide frequent opportunities for agricultural and environmental interests to work with urban planners to find creative ways to enhance developed areas and lessen development pressure on open space and agricultural lands.
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H2. Protect and improve long term agricultural productivity of farmed lands in the watershed. Because there is a limited amount of farmable acreage in the Napa River watershed, agricultural growth can continue only by protecting the long term productivity of what land there is. Lost topsoil takes hundreds of years to replace, and tainted water can make even the best soil unproductive. Thoughtfulness and foresight can, however help to maintain the ability of watershed resources to support agriculture indefinitely.
| H2.1.
| Promote wide use of the California Irrigation Management Information System (CIMIS) through regular publication of CIMIS data, and provide education in its use for pesticide and water use reduction.
|
| H2.2.
| Implement practices that will control erosion and loss of topsoil from farmed areas (see "Reduce Soil Erosion" objective for recommended practices).
|
| H2.3.
| Recycle vegetative and animal wastes from agricultural production through composting and reapplication as soil amendments.
|
| H2.4.
| Develop grazing plans for livestock areas that will improve annual and long term production per animal unit acre.
|
| H2.5.
| Plant non crop areas with native vegetation to increase biodiversity and decrease necessity for pesticide use.
|
| H2.6.
| Stabilize creek banks and drainage canals with bio-engineering techniques to curb loss of farmlands to bank collapse and stream migration.
|
| H2.7.
| Promote development of appellation stewardships to provide site-specific examination of resource conservation farming techniques for use in community based resource protection.
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H3. Increase educational opportunities in sustainable practices for all watershed land users. Long term planning requires knowledge of a wide range of disciplines. Providing opportunities for individuals to increase their knowledge of the watershed's social and natural systems also provides greater opportunity for creative planning and long term success.
| H3.1.
| Hold a regular series of jointly sponsored workshops to provide technical education for agriculture interests; urban interests; and rural residential land users.
|
| H3.2.
| Establish classes at the Napa Valley Community College in sustainable land management.
|
| H3.3.
| Develop partnerships with agencies, education institutions, private landowners and grower organizations to implement and improve Integrated Pest Management techniques.
|
| H3.4.
| Organize a permanent forum for agricultural and environmental interests to foster greater direct communication on resource conservation issues.
|
| H3.5.
| Provide specific training to city and county planning departments in sustainable land use planning and management.
|
| H3.6.
| Support the use of the sustainable land use elements of the school curriculum developed by the Napa County Resource Conservation District.
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H4. Use natural progressions and systems to increase water and soil retention, and to decrease long term maintenance costs of the watershed.
| H4.1.
| Stream stabilization work and drainage ditch construction should utilize methods that reflect stable stream morphology.
|
| H4.2.
| Establish and promote programs that manage for increases in indigenous perennial grasses in the watershed.
|
| H4.3.
| Reforestation, including agroforestry, of unused lands should be encouraged.
|
| H4.4.
| Continue to seek technical and financial assistance to eliminate noxious exotic plant species such as star thistle and French broom through range management, in order to restore the productivity of watershed lands.
|
| H4.5.
| Develop conjunctive use of water resources throughout the watershed, with emphasis on the upper Napa River and Carneros.
|
| H4.6.
| Where possible and technically feasible, reestablish wetlands to filter storm runoff and attenuate flooding.
|
| H4.7.
| Develop grazing management plans and controlled burning to manage fuel loads in fire hazard areas.
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H5. Promote environmentally sensitive planning and development. Improving the efficiency of existing developed areas is preferable to expansion into open or agricultural areas. Many of our present developed areas can be made more efficient and useful through careful planning.
| H5.1.
| Concentrate improvements in already developed areas.
|
| H5.2.
| Build close to existing functioning roadways to minimize alterations from roadway expansion and extension.
|
| H5.3.
| Develop ways to re-use or redevelop existing structures before building new ones.
|
| H5.4.
| Revitalize and restore urban waterways as functional amenities.
|
| H5.5.
| Keep concentrated development away from sensitive areas such as riparian corridors and wetlands.
|
| H5.6.
| Encourage development to utilize existing roads to minimize construction of new rural road cuts.
|
| H5.7.
| Cluster homes on contiguous parcels to minimize impacts on open space and wildlife habitat.
|
| H5.8.
| Make erosion control a priority when designing site access and building construction.
|
| H5.9.
| Plan for plumbing to utilize gray water where appropriate.
|
| H5.10.
| Avoid development of buildings or roads near sensitive habitats.
|
| H5.11.
| Design and site adequate on site waste disposal systems that can be easily maintained.
|
| H5.12.
| Emphasize protection of entire habitat units, instead of just single tree or single feature preservation.
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H6. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| H6.1.
| Conduct a cooperative biological assessment of the watershed and identify sensitive areas to be included in a Geographic Information System database for public and private reference.
|
| H6.2.
| Form a cooperative watershed assessment team to classify the Napa River and tributaries by reach according to the Rosgen classification scheme.
|
| H6.3.
| Establish bank and channel monitoring points in major tributaries to monitor channel stability, and to track the effects of changing land use over time.
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Background
Water development has long been separated into three distinct categories: groundwater, surface water, and reclaimed water. Hydrologic systems, however, are rarely so segmented. Availability of groundwater is directly related to surface water conditions, and groundwater conditions have an impact on surface water supply. As groundwater drops, for instance, the level of surface streams drops as well. High water table lands increase rainfall runoff, and can recharge streams that may otherwise be losing flow to lowered water table elevations. Managing the water system as a whole allows use of groundwater when it is at its peak, allowing more surface water to be used for wildlife, or stored for use when seasonal drops in water tables occur. This type of combined water use is called "conjunctive use" of the resource, and requires a degree of monitoring and planning that is not presently part of the usual water use pattern. Water management also includes the maximum reuse of water for further beneficial uses once it is treated.
Cumulative changes in land management practices can be significant in water management. In addition to the obvious benefits of water conservation techniques, practices can be implemented that allow more water to penetrate the soil and less to run off into drainages. Napa River watershed soils vary in their ability to hold water, from about 1 inch of water per foot of depth to over 3 inches per foot of soil depth. Easier penetration through the soil surface and subsequent percolation to greater soil depths brings greater storage of water in the soil itself. That additional storage is then available for river recharge during the summer, for use by pumping from wells, and for stabilization of the diverse biological community in the valley. The additional infiltration of rainwater into the soil would also reduce the amount of runoff by an equal amount each year, helping to decrease local flooding.
The following recommendations are intended to contribute to the long term availability of adequate water supplies in the Napa River watershed by making better use of that which we already have. Decreasing reliance on outside water supplies increases the security of the valley's domestic and agricultural economies. Development of a complete water budget will also allow the enhancement of Napa Valley's fisheries, and provide long term support for the return of a strong anadromous fish population to the region.
I1. Estimate water budgets for tributary watersheds to the Napa River, including time distribution and existing diversion amounts, for use in local and individual land use planning
| I1.1.
| Calibrate tributary flows for accurate estimates of rainfall runoff and runoff potential.
|
| I1.2.
| Estimate groundwater recharge rates for tributary watersheds.
|
| I1.3.
| Expand community voluntary groundwater monitoring, with the assistance of the USDA Natural Resource Conservation Service, the Napa County Flood Control and Water Conservation District, and the Regional Water Quality Control Board.
|
| I1.4.
| Cooperate with the California Department of Fish and Game and other local and state agencies, to estimate optimum wildlife minimum flows in the river and tributaries.
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I2. Encourage conjunctive use of groundwater and surface water in the watershed.
| I2.1.
| Utilization of groundwater during dry times when surface water is less available should be augmented with use of surface water during times of high availability in wetter months.
|
| I2.2.
| High winter surface water runoff should be directed into facilities such as floodplain wetlands, to encourage groundwater recharge in wet months, especially in the Tulocay-Coombsville area, and in the lower Milliken Creek area.
|
| I2.3.
| Assessment of the state of Valley aquifers, particularly in and around St. Helena, should be made in order to determine rates and sites of renewable extraction (safe yield) of groundwater. Establish a long term water budget and aquifer monitoring program based on this analysis.
|
| I2.4.
| Utilize the Geographic Information System database as a common reference for water use and development decisions in the watershed.
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I3. Increase the reuse of treated waste water for irrigation and wildlife habitat enhancement and restoration
| I3.1.
| Investigate feasibility of expansion of the use of dual plumbing systems for wastewater reuse where the recycled water is or may be available, in order to replace potable water use for irrigation and wildlife management.
|
| I3.2.
| Utilize properly designed gray water reuse systems for on site irrigation.
|
| I3.3.
| Priority use for recycled water should be to supplant the use of potable water where potable water is presently used for non-consumptive purposes.
|
| I3.4.
| Establish trials in the watershed to determine the feasibility of using constructed wetlands as part of waste water treatment for wineries and homes.
|
| I3.5.
| Define a local lead agency to collect data and develop a watershed wide water management plan.
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I4. Increase the use of the California Irrigation Management Information System (CIMIS) by water users throughout the watershed. CIMIS information is recorded daily at three stations in the watershed: Carneros, Angwin and Oakville. The information is available by personal computer and modem on a daily basis in many different formats.
| I4.1.
| Use CIMIS information to publish lawn irrigation recommended amounts for areas represented by each of the three stations.
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| I4.2.
| Provide training for homeowners, park managers, landscapers and agricultural interests in the acquisition and use of CIMIS data.
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| I4.3.
| Utilize CIMIS data to plan irrigation scheduling for public parks, golf courses, industrial parks, cemeteries, and other large irrigated areas.
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| I4.4.
| Arrange for regular publication of CIMIS data in local press media.
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I5. Increase awareness and use of efficient water management in urban areas. The share of water use by urban areas in Napa is increasing as the urban population grows. To help maintain the supply of local water, and to decrease the reliance on imported water, it is important to make the most efficient use of water wherever and whenever possible.
| I5.1.
| Encourage the use of low water use plants in urban landscaping.
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| I5.2.
| Provide regular continuing information about water conservation techniques.
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| I5.3.
| Continue conservation programs such as the low water volume toilet exchange.
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| I5.4.
| Minimize irrigated turf areas in parks and other recreation areas to only high traffic zones such as ball fields.
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| I5.5.
| Increase the use of permeable pavement surfaces to increase groundwater recharge.
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I6. Data management and public outreach. Communication, education, and monitoring are critical aspects of systems management. More complete knowledge of watershed conditions allows more creative options for maintaining system balance. A community that has a high degree of awareness of the condition and trends of their watershed is better equipped and more likely to manage the watershed in a thoughtful, sustainable manner.
| I6.1.
| Maintain a program of water conservation awareness in the watershed.
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| I6.2.
| Form a cooperative venture with schools, private organizations and government agencies to establish demonstration gardens and herbariums to display alternative home landscaping using native and other low water use plants.
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| I6.3.
| In cooperation with the Regional Water Quality Control Board, establish a network of aquifer monitoring stations, and begin a program of accurate determination of well head and well screen elevations of the monitored wells.
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| I6.4.
| Cooperate with the Regional Water Quality Control Board in developing a voluntary, cooperative groundwater management strategy.
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© Copyright Napa County Resource Conservation District, 1996.
