An ordinance that would protect streams in Marin County’s San Geronimo Valley is winding through official channels toward an eventual decision from the county board of supervisors next spring.
The Marin County Planning Commission on Dec. 13 approved the Stream Conservation Area (SCA) Ordinance, with a few modifications from the Marin County Community Development Agency.
The public will be able to make comments and help shape the ordinance until March, when supervisors are expected to take up the proposal.
According to the county, there are 1,485 households in the San Geronimo Valley, based on census information. Near Marin’s geographic center, the valley is surrounded by wooded open space areas, just west of densely populated parts of central and eastern Marin.

The draft ordinance would amend the county’s zoning ordinance to establish a buffer of 100 feet or more where development is restricted from the stream bank. It would also create standards for development in the buffer and provide consistent permit review procedures and requirements.
The ordinance would help guide homeowners and contractors, and “would expand the existing site plan review provisions to encompass development activities proposed within SCAs in the San Geronimo Valley,” according to the county.
The proposed ordinance builds upon efforts to protect streams and habitat for endangered coho salmon and steelhead trout in the valley, consistent with riparian protection policies from the 2007 Marin Countywide Plan. Lagunitas Creek in the San Geronimo watershed supports one of the largest populations of wild federally listed endangered coho salmon, steelhead trout, and chinook salmon in Northern California.
The draft SCA ordinance, supporting reference materials, and a subscription option for e-mailed updates are available online. Comments or questions about the proposed ordinance can be sent to planner Kristin Drumm.