Town Hall offices will be closed Monday, May 27 in observance of Memorial Day.

Creek Maintenance Fact Sheet

Creeks In Your Yard
Natural creeks flow throughout our community, adding beauty, tranquility, and economic value to neighboring properties. They serve as refuges and avenues of travel for wildlife, as well as an area for storm water drainage. If your property is bordered by a creek, this natural resource can be a wonderful amenity- however there are additional responsibilities and things to be aware of when you live next to a creek. This fact sheet has been prepared to provide information and resources to creekside property owners in response to many inquiries concerning creek maintenance. These facts and resources relate to bank repair projects and routine maintenance activities within the creek or on the creek bank.

Geographic Overview
The San Anselmo Creek is the largest stream the Corte Madera Creek watershed, which encompasses 28 square miles of central Marin County and drains the Ross Valley. San Anselmo Creek originates in Cascade Canyon, in Fairfax. Upstream of the Town of San Anselmo, it is joined by Fairfax Creek, Sleepy Hollow Creek, and Sorich Creek. Downstream of the Town of San Anselmo it merges with Ross Creek, at which point its name changes to Corte Madera Creek. The creek enters the San Francisco Bay near the College of Marin.

Ownership and Easements
Most of the land bordering our creeks is privately owned, with property lines typically extending to the centerline or the banks of the creek. In either situation, this means the primary responsibility for creek bank repair and maintenance falls to the property owner. The Town has some easements on private property, however the type of easement vary from property to property and typically do not assign responsibility for regular routine maintenance of the creek. Easements most often provide access to areas or allow for the construction and maintenance of specific facilities. Property owners can find out about these easements in the title reports for their properties.

Permits for Creek Bank Repair and Maintenance Work
The water flowing through private property and the unique habitat represented by the creek are protected by State and Federal laws, therefore several government agencies have jurisdiction over activities within local creeks. The following provides a brief summary of the primary applicable regulations:

Federal: Since the creeks are considered “waters of the United States,” the U.S. Army Corps of Engineers has the authority under the Clean Water Act (Section 404) for activities that involve the placement of fill (including rip rap) within the stream channel. The National Marine Fisheries and Fish and Wildlife Service also regulate habitat in the creek and adjacent vegetation. Properties in flood prone areas have additional requirements to meet through the
National Flood Insurance Program, which is administered by FEMA, the Federal Emergency Management Agency.

State: The State of California Regional Water Quality Control Board (RWQCB) and the State Department offish and Wildlife (CADFW) have the authority over work in stream channels for both water quality and habitat issues.

Local Requirements

Work on creek banks is also subject to Town and County regulations depending on the type of work proposed. Construction of any structure adjacent to the creek is subject to local building permits and these projects should begin with a visit to the Town of Fairfax Building Department. The Town’s ordinance requires facilities to be set 15 feet back from the top of the creek bank.

Routine Creek Maintenance by Property Owners

The creek channel is not a static environment and erosion is a natural part of the creek system. Properties in close proximity of the creek create a situation where significant bank erosion is undesirable, requiring ongoing maintenance to keep erosion in check. As previously stated, required maintenance of creek banks is the responsibility of the property owner and in many cases requires permits. Property owners should seek advice before they attempt creek bank maintenance activities. Some activities can be more harmful than helpful. For example, many property owners believe the creek should be devoid of any debris, including woody materials, and that vegetation should be removed to prevent flooding. However, vegetation is vital to prevent erosion and both vegetation and woody materials are essential to a healthy creek environment. One of the easiest things property owners can do is keep the creek bank as open and free of structures or stored materials as possible. Decks and structures placed too close to the creek bank tend to destabilize the bank and create problems during flood events. Another important activity is routine maintenance of large trees. Fallen trees or large limbs can plug drainage systems and cause flooding during a storm.

Activities that DO NOT Require Permits:

• Removing manmade trash or debris that is on the creek bank or in the creek.
• Minor trimming of vegetation on creek banks. Focus on removal of low limbs while maintaining upper vegetation for creek shading.
Activities that DO require permits:
• Large scale debris removal, other than manmade, from the streambed below ordinary high water. (The ordinary high water mark is typically about half way up the bank in the larger creeks, but is officially determined using several channel characteristics and in small channels could include to the top of bank.)
• Tree removal
• Alteration/armoring of creek bank
• Dredging of the channel
• Any kind of physical structure
• Dumping dirt and rocks into channel or eroded banks.
Creek Maintenance by the Town
The Town of Fairfax partners with the Marin County Flood Control District to provide limited creek maintenance for flood control purposes. The Public Works Department surveys the creeks to identify problem areas, which are evaluated on a priority basis, and work is conducted pending available funds. In some cases property owners will be advised of work that should be done. In an emergency situation ( a fallen tree blocking the flow line during heavy storms, a mud slide, etc.) the Town may take action, to alleviate the flooding of surrounding properties.
On-line Resources:
Marin County Water Quality Program:
Ross Valley Flood Protection & Watershed Program:
US Geological Survey Stream Gauge in Ross: no= 11460000
San Anselmo Creek Height:
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