Watershed Overview

The Mill Creek Watershed is an important and picturesque watershed within the Russian River basin. With its lower reaches located only 3 miles west of Healdsburg, Mill Creek is a beautiful home for many rural residents that have excellent access to the conveniences of a vibrant Sonoma County city. Located close to the heart of the famous Sonoma County wine country, it is a diverse watershed in both geography and landuse.

The Mill Creek watershed is located within the Russian River watershed and is a major tributary to Dry Creek. Mill Creek enters Dry Creek less than one mile before it confluences the Russian River in the Dry Creek Valley. Its watershed is bordered by the Austin Creek watershed to the west, Porter Creek to the south, Peña Creek to the north (also a Dry Creek tributary), and the Dry Creek mainstem to the east.

The Mill Creek watershed drains an area of approximately 24 square miles and is composed of 3 primary sub basins: Palmer Creek, Wallace Creek, and Felta Creek. The topography of the watershed is quite dramatic, with elevations ranging from over 1,500 ft in the headwaters to approximately 60 ft in the Dry Creek Valley. The creek flows primarily west to east through steep wooded canyons to the flats and agricultural lands at its confluence. Mill Creek and its tributaries comprise 29 miles of blue-line stream within the watershed

There are no incorporated cities or towns within the Mill Creek watershed. Landholdings within the Mill Creek are primarily privately owned. While there are no public lands within the watershed, Sonoma County Agriculture Preservation and Open Space District is working with at least two landowners to develop Conservation Easements

 

Landuse (historical and current)

Initial settlements in the watershed consisted of prehistoric villages on the lowland areas along the Dry Creek alluvial plain and along Mill Creek. These early inhabitants were Southern Pomo Indians who cultivated the land in their traditional ways through burning, tilling, sowing and pruning native plants.  American and European settlers began arriving in the early 1800s.  By 1841, the area was included within the 49,000 acre Mexican land grant deeded to Henry Fitch termed Rancho Sotoyome, named after the local tribe whose chief was referred to as Chief Soto. Rancho activity from 1840 to 1850 introduced livestock grazing, and farming for crops and feed. Fruit crops and grape vines were also introduced at this time. As settlement increased in the area, the need for a sawmill and flour mill was apparent and in 1850 the first sawmill to operate in northern Sonoma County was erected in Mill Creek. The original site was located near the “Upper Falls” on Mill Creek and later moved to a point just below the second falls and continued operating until 1881. This logging period lasted for several years. Redwood logs supplied beams for construction and the developing railroad and tanbark was sent to a Santa Rosa tannery.

In the flatter areas of the watershed, the forests were often cleared and converted to prune orchards, vineyards and grassy openings for livestock grazing. In the 1920s, the name Venado was given to identify the settlement in Mill Creek and a post office was erected. Quite a few of the early settlers were former engineers who bought 40-acre plots of land from the original land owner. A crushed stone quarry was mined in the early 1900s for building blocks and cobblestones. (Historical information from healdsburgmuseum.org)

Over time, wine grape growing continued to expand throughout the Dry Creek Valley, and since the time of prohibition in the 1920s, it has emerged as the predominant land use in the area and is recognized as world class grape growing and wine producing region.

Today, the Mill Creek watershed is completely privately owned. Most of the parcels are less than 600 acres in size. In the lower elevations where Mill Creek meets up with Dry Creek, land use is primarily made up of vineyards and wineries. Going up the watershed, the valley narrows and the steep forest-covered hills limit the amount of agriculture that can take place. Many of the landowners pursue a diverse mixture of land uses that includes residential dwellings, winegrape growing, vegetable farming, fruit production, livestock production and in some cases small wineries that are open to the public.

 

Vegetation

Vegetation in the Mill Creek watershed is typical of the North Coast Mediterranean vegetation types. Where temperatures are relatively high and precipitation and soils are shallow, oak woodlands and chaparral-associated plants predominate. In the cooler and wetter areas, soils are deeper, and mixed evergreen forest and oak woodland communities occur. Redwood and Douglas fir dominate in cooler, moister areas, whereas hardwood evergreens, such as tan oak, madrone, live oak, and bay occur on well-drained slopes. On southern exposures and the edges of the mixed forest can be seen the northern oak woodland type. Oregon and black oak and Manzanita dominate here, while coniferous trees are scarce. Much of the grassland in the watershed has developed on land cleared of hardwoods and conifers for grazing. Numerous types of grasses, both exotic and native cover these open areas. The riparian vegetation along creeks include: cottonwood, willow, valley oak, live oak and alder with some areas supporting buckeye, poison oak and toyon.

 

Fish and Wildlife

Several listed species are found within the Mill Creek watershed. Among the endangered species are the Oncorhynchus kisutch, coho salmon, and the Syncaris pacifica, the CA freshwater shrimp. Threatened species that have been documented in the watershed include the Rana draytonii, CA red-legged frog, the Oncorhynchus mykiss, the steelhead trout, and the Strix occidentalis caurina, northern spotted owl. Habitat levels for each of these species vary throughout the Mill Creek watershed. To improve habitat in the watershed, recommendations include increasing riparian canopy, road repairs to reduce sediment delivery into stream, and increase instream habitat with structure installation and wood retention.

 

Roads

The history of logging in the Mill Creek watershed has left a lasting impression on the landscape. One of the primary impressions comes in the form of legacy logging roads. With the invention of tractor logging in the 1950’s it became popular practice to cut small roads into where logging was taking place and use these roads to drag, or skid, the logs to a broad landing areas. From these landings, logs could be loaded onto trucks and taken out on much larger roads to local mill sites. Many of these roads were cut across steep and geologically unstable hillslopes in close proximity to streams and were not installed with proper drainage designs in mind. In the years since the time of heavy logging in the Mill Creek watershed, these legacy roads continue to have detrimental effects on the hydrology of the area by diverting streams out of their natural channels and by eroding and contributing fish-choking fine sediment to the waterways.

Current and Past RCD Programs

Planning

  • The RCD worked on a design for a Large Woody Material (LWM) project along Mill Creek with funding from the Sonoma County Water Agency and the National Fish and Wildlife Foundation. The design has over 51 sites for a one mile stretch of creek. The design will be proposed to the Department of Fish and Wildlife’s Fisheries Restoration Grant Program (FRGP) in 2017.
  • The RCD has started developing an in-stream habitat enhancement project in Mill Creek with the goal to enhance habitat complexity, cover, and scour. Additional funding and landowner interest is sought to design a larger project.

 

Watershed Scale Planning

  • The Mill Creek Watershed Management Plan is available for download on our Resources page. The goal of the plan is to work with watershed landowners and stakeholders to investigate and evaluate current and historic conditions as well as recommend a prioritized set of actions to improve water quality, sustain agricultural operations, and improve riparian and aquatic habitat conditions.

 

Water Resource Management

  • Sonoma RCD is one of six partners in the Russian River Coho Water Resources Partnership, a National Fish and Wildlife Foundation Coho Keystone Initiative. The Partnership was formed in 2009 to develop a systematic approach to improve streamflow and water supply reliability in Mill Creek and four other sub-watersheds critical to coho recovery in the Russian River Watershed. The Partnership’s goal is to further the recovery of coho salmon through habitat and streamflow enhancements and improve water security.
  • The RCD is currently outreaching to landowners to develop and implement rain water storage projects along key stream reaches with the goal of improving water reliability for landowners and to keep more water in the stream during the dry season for salmonids. cohopartnership.org
  • Water Quality Monitoring Program is ongoing in several of the watersheds surrounding Mill Creek. The Sonoma RCD is working toward establishing a monitoring program in Mill Creek as well.

 

On-the-Ground Projects

  • The RCD plans to implement eleven Large Woody Material (LWM) sites on Felta Creek, a tributary to Mill Creek. The goal of the project is to increase habitat complexity, cover, and refugia for coho salmon. The design calls for the Accelerated Recruitment method, which consists of cutting trees in the riparian corridor and wedging/placing them in the creek for habitat. The project was made possible from funding from the Department of Fish and Wildlife and implementation will happen in Summer 2016.
  • Assessment of existing large wood instream habitat enhancement structures previously placed in Mill Creek and its tributaries as part of the Mill Creek Watershed Management Plan.
  • Implementation of the Salt Creek Habitat Restoration Project along 3,000 ft. of Salt Creek (tributary to Mill Creek) to lay back and revegetate eroding banks, and install wood structures designed to create pools and shelter to improve habitat quality for endangered salmonids. 
  • The Mill Creek Watershed has long been a focal area for the RCD’s Rural Roads Improvement Program. To date, road improvements have been completed in Palmer Creek and Felta Creek (both tributaries to Mill Creek). The RCD continues to implement projects identified through outreach and stream assessments.

For more information about the Mill Creek Watershed please contact Justin Bodell at 707.569.1448 ext 107 or jbodell@sonomarcd.org.