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Napa County Resource Conservation District |
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Napa County Resource Conservation District |
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Dry Creek Watershed Stewardship
Watershed residents, with the help of the Napa County Resource Conservation District, established the Dry Creek Watershed Stewardship in April of 1996. The Mission of the stewardship is to preserve and enhance the natural, cultural and economic resources of the watershed. We can work together as neighbors, using local energy and expertise to improve and protect our resources. By building cooperative relationships with each other, our public agencies and local government, we become more effective in achieving our goals, and can effectively shape the future of our watershed. To find out more about the Dry Creek Watershed and the stewardship, please read on!
What is the Dry Creek Watershed?
A watershed is the land over which water passes on its way to join a major body of water. The Dry Creek watershed spans approximately 15,000 acres or 22 square miles in the Mayacamas range in western Napa County. The borders of this watershed are formed by three peaks and the ridges that connect them: Mt. Veeder, Bald Mountain, and Mt. St. John. From its headwaters near Mt. St. John, Dry Creek flows for nearly 15 miles until it joins the Napa River near Yountville. The watershed supports a variety of economic activities such as vineyards, cattle grazing, small orchards, and truck gardens as well as homesites.
The principle rock types exposed around Dry Creek are sedimentary sandstone and alluvial. The soils weathered from these materials are highly erosive when stripped of cover. The vegetation on the northeast facing slopes is evergreen and coniferous forest. Chaparral covers the southwest-facing slopes. Dry Creek is home to native animals including deer, coyotes, foxes and black bears and non-native wild pigs and turkeys. Federally listed species such as the red-legged frog and northern spotted owl are also found here. Historically, Dry Creek had populations of both coho salmon and steelhead. The coho are now extinct here but Dry Creek remains an important steelhead (also a threatened species) spawning tributary in the Napa River watershed.
History
What did the Dry Creek Watershed look like a thousand years ago? What did it look like even one hundred years ago? How have climate changes, floods, fire, and man affected the area in the past? It is beneficial to look at the past to help plan for the future. The Stewardship’s history committee is beginning to collect information to develop a benchmark for future reference and to better understand how the elements of the watershed are changing.
The history committee is assembling the written and oral histories of long term residents, as well as old photographs and maps. Subject areas being explored include Native American life, pioneer life, agriculture, logging and mining, climate, fires, and wildlife. Some wonderful stories have emerged from "History Teas" hosted by the Dry Creek Watershed Stewardship Group. For instance, not so very long ago stage coaches took visitors from Oakville up the narrow Wing Canyon Road to resorts on Mt. Veeder. A cinnabar mine on Mt. St. John produced quicksilver to supply munition manufacturers during World War II. Local residents remember catching 18 pound steelhead out of Dry Creek and piling the whole family into the horse drawn buggy for camping excursions along the creek. Major flood events occurred in 1881-2, 1955 and 1982. A huge fire that swept through the area in 1942 was started by someone smoking bees. Native Americans of the Wappo tribe once lived throughout the area.
The stewardship would appreciate any residents help to document the historical, geological and ecological aspects of the Dry Creek Watershed. With this information, we can develop a better understanding of the processes that have shaped the past and will shape the future of the watershed.
Please Join Us
Activities of the Dry Creek Stewardship Group include:
- Monthly evening meetings for educational presentations on watershed topics including wildlife, stream and watershed dynamics, fire protection, soil conservation geology, groundwater, native and exotic plants, and local history.
- The development of a Watershed Plan with printed materials providing background information and resources for watershed residents.
- A fish habitat survey of the 15 mile length of the creek and its tributaries, and the development and implementation of voluntary salmonid habitat restoration projects.
- Ongoing data gathering of water quality, rainfall, vegetation, wildlife, and erosion in the watershed.
- History Teas to compile a history of the watershed based on the memories of long-time local residents.
Steering Committee:
The Dry Creek Watershed Stewardship Group is led by a dedicated group of volunteers from the watershed. Anyone can be on the Steering Committee and we welcome your involvement. The Committee meets once a month to plan activities and educational presentations. The current committee members are:
Chip Bouril, 944-2058
Joyce Bowen, 944-2822
Al Buckland, 252-1800
Jay Cook, 944-9704
Bill Harris, 944-2030
Annie/Gary Margadant, 257-3351
Richard Niemann, 226-7764
Geographic Information System (G.I.S.) maps of the Dry Creek Watershed have been developed as a result of the "Habitat Typing" work done by volunteer members of the Stewardship. Using California Department of Fish & Game (DFG) protocols detailed in the California Salmonid Restoration Manual the main stem of the creek was surveyed in summer of 1997. The GIS maps were prepared by the DFG computer mapping personnel from the survey data. These graphical representations of the stream’s salmonid habitat conditions, particularly with color coding representing differing conditions, are an excellent step forward in visualizing and developing restoration plans for the watershed. Maps follow that detail Dry Creek’s Stream Channel Type, Tree Canopy Coverage, Pool Depth and Stream Bed Embeddedness; all important considerations in the development of a site specific watershed restoration plan.
Channel Type
Streams can be classified according to a standardized classification method developed by D.L. Rosgen commonly called the Rosgen Method. The streams are coded and Dry Creek includes the following channel types:
A4: Steep, narrow, cascading, step-pools.
B2: Moderately entrenched, moderate gradient, riffle dominated channel.
F1: Entrenched meandering riffle/pool channel on low gradients, bedrock channel
F2: Entrenched meandering riffle/pool channel on low gradients, boulder channel.
F3: Entrenched meandering riffle/pool channel on low gradients, cobble channel.
F4: Entrenched meandering riffle/pool channel on low gradients, gravel channel
In these different channel types, different restoration projects are described as being Good, Fair, or Poor according to the DFG Restoration Manual. Such projects might include measures such as bank-placed boulders, plunge weirs, wing deflectors, and cover logs.
If you are interested in a "Channel Type Map", please contact our office.
Percent Canopy
Tree canopy or canopy density produces shade on the stream, keeping its waters cool and suitable for cold-water fish species such as juvenile steelhead. Overhanging trees and other vegetation are a source of the insect food supply for juvenile salmonids and likewise the vegetation is a source of food for the insects or "invertebrates" in this system of interdependence. Tree cover is thus a very important consideration in assessing the health of a steelhead stream. The percentage measurement is taken in the middle of the stream with a handheld device called a "densiometer". With this G.I.S. mapping it becomes clear where the tree canopy over a stream is adequate or in need of improvement.
If you are interested in a "Percent Canopy Map", please contact our office.
Pool Depth
Pool Depth is of critical importance in steelhead stream for many reasons. Pools provide cooler water, cover from predators, and refuge when summer water levels drop. In drought conditions deep pools become extremely important to the survival of juvenile salmonids. The downstream section of pools or "pool tail" often contain the most suitable gravels for spawning. It is generally accepted that good steelhead stream habitat consists of 50% pool habitat which should be at least 3 feet in depth. Pools are often formed when "large woody debris" such as logs fall in the stream and winter high flows rush the water over the log, scouring out a pool below the log. An absence of a natural amount of large woody debris in streams leads to an absence of pool habitat. This is a problem in many Napa River tributary watersheds where the normal management practice has been to remove any large woody debris from the stream.
If you are interested in a "Pool Depth Map", please contact our office.
Cobble Embeddedness
Cobble embeddedness or pool tail cobble embeddedness is a simple measure of sediment in a streambed by observing the depth of the sediment around rocks. It is done in the pool tail where salmonid spawning is likely to occur. The measurement is taken by removing a cobble from the streambed and observing the line between the "shiny" buried portion and the duller exposed portion. The percentage is the measurement of how much of the rock is buried. Too much sediment in the pool tail makes successful salmon spawning unlikely.
If you are interested in a "Cobble Embeddedness Map", please contact our office.
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