Petaluma River Watershed

Watershed Description

Located in southern Sonoma County, and a portion of northeastern Marin County, the Petaluma River Watershed encompasses a 146 square mile, pear-shaped basin. The watershed is approximately 19 miles long and 13 miles wide with the City of Petaluma near its center.

The headwaters and ephemeral tributaries of Petaluma River begin on the steep southwest slopes of Sonoma Mountain, the southern slopes of Mecham Hill, and the eastern slopes of Weigand’s Hill and Mt. Burdell. The confluence of Willow Brook, Liberty Creek, and Weigand’s Creek form the headwaters of the Petaluma Watershed just upstream of Rainsville Road and Stony Point Road. The Petaluma River itself flows across the Denman Flat area and through the City of Petaluma. Tidal influence extends upstream of the confluence with Lynch Creek (beyond the railroad crossing).

Mountainous or hilly upland areas comprise 56% of the watershed. Thirty-three percent of the watershed is valley, and the lower 11% are salt marshes. Sonoma Mountain at 2,295 feet is the highest point in the watershed. The Petaluma River empties into the northwest portion of San Pablo Bay.

The lower 12 miles of the Petaluma River flow through the Petaluma Marsh, the largest remaining salt marsh in San Pablo Bay. The marsh covers 5,000 acres and is surrounded by approximately 7,000 acres of reclaimed wetlands. Prior to reclamation, marshland elevations ranged from mean sea level to 3 feet above mean sea level.

 

Watershed Goals and Objectives

The City of Petaluma has cooperated with the RCD on various projects including the monitoring of effluent disposal on ranch lands. The RCD continues to work with landowners addressing individual questions concerning erosion, animal waste and related problems.

The following goals are taken from the Petaluma Watershed Enhancement Plan (July 1999):

  • Establish a local watershed council for residents and organizations to fund and coordinate watershed enhancement activities and keep one another informed;
  • Improve water quality and ground water recharge in the watershed with the ultiamte purpose of removing the Petaluma River from the RWQCB Impaired Waterbody List 303d;
  • Support the viability of agriculture in the community; and
  • Conserve and enhance existing wildlife habitat.

Current Projects and Funding

  • Current flood control, channel maintenance, and revegetation projects for the Sonoma County Water Agency include sections of Lichau Creek, Adobe Creek, and a specific reach of the Petaluma River. The RCD will be working closely with the City of Petaluma, the Unitied Anglers of Casa Grande, and the local neighbors.
  • SSCRCD is pursuing grant funds to assist the Mary Collins Charter School with the installation of a nature trail on the school grounds. Once installed, this site will be maintained by the students, teachers, and parents, providing an educational tool and additional native habitat for generations to come.

Accomplishments

  • In 1999, the SSCRCD in cooperation with local landowners, created and published the Petaluma River Watershed Enhancement Plan. The top goal of the plan was to form a watershed council or stakeholder group to further implement the goals and objectives of the plan.
  • The SSCRCD has received various state and federal grants and fine monies over the years to assist landowners in restoration and enhancement of their lands and address other environmental concerns. Projects include:
    • Marin Creek flood control, channel maintenance, and restoration work;
    • Santa Rosa Junior College (Petaluma campus) riparian habitat restoration on Capri Creek;
    • Lichau Creek, Lynch Creek, Willowbrook Creek erosion repairs;
    • Sponsoring a levee maintenance permit;
    • Coordinating with the USDA's Natural Resources Conservation Service, the RCD completed an emergency project for creek bank erosion.
  • Through the NRCS Environmental Quality Incentives Program (EQIP), $560,792 has been spent throughout the Petaluma River watershed to improve water quality and minimize erosion on dairies, livestock ranches and vineyards from 1999 through 2004.
  • The District partnered with several other Bay area RCDs to complete demonstration projects on several horse facilities in an effort to demonstrate the benefits of composting manure on water quality and promote responsible stewardship. This project was funded by the Regional Water Quality Control Board. Our local demonstration facility is located in Petaluma. Check out the publication and fact sheets that were produced through this grant.

©2004 Southern Sonoma County Resource Conservation District