Creek Care

Creek Protection

Creek setbacks are generally acknowledged to be essential if creeks are to retain any of their natural functions of creeks in developed areas. These functions include serving as wildlife corridors, providing habitat for fish such as the threatened steelhead, allowing for lateral movement, filtering out pollutants by means of riparian vegetation on sloping creek banks or marsh vegetation on level shorelines, and conveying flood waters. A natural creek also has an esthetic value and cooling effect readily recognized by any homeowner living by a creek.   

Regardless of their value, our creeks and their environs continue to be degraded by structures and paving that are constructed too close to the channel and by the armoring of creek banks to protect these structures. Armored banks lead to narrower channels, faster flowing floodwaters, additional erosion of creek banks both upstream and downstream, and further armoring. Destruction of native vegetation and water diversions also degrade the riparian corridor. All this destroys the very things we value about our creeks—and may result in bringing about what San Anselmo and Fairfax prevented the Army Corps from achieving in the 1970s: the substantial channelization of San Anselmo, Fairfax, and Sleepy Hollow creeks.  

Effective protection measures should be incorporated in local codes to apply to alterations within the creek channels and improvements on property adjacent to the creeks. An ordinance would have to be flexible enough to fit the varied conditions of lots within the town, while not allowing so many exceptions that it is useless. Marin County has been working on a Stream Conservation Ordinance for decades but because of property owner resistance has had limited success in implementing it. 

We urge local jurisdictions to draft riparian corridor protection plans, implemented by ordinances, to control development on properties in the vicinity of our creeks, and to ensure that when development occurs, riparian habitat is simultaneously improved. 

Recommendations for Creek Protection Policies and Ordinances and Creek Corridor Management Plans

Friends of Corte Madera Creek Watershed makes the following recommendations for creek corridor management plans and creek protection policies and ordinances: 

• Natural features and functions of a creek corridor should be protected. These include sloping banks; native vegetation; a riparian zone capable of filtering out pollutants, especially sediment; wildlife habitat and passage; aquatic life; a degree of meandering of the stream; esthetic value; bank cover to reduce erosion; and roughness of banks to attenuate flood waters. 

• The California Code of Regulations Title 14, Section 1.72 defines a stream, creek or river as “a body of water that flows at least periodically or intermittently through a bed or channel having banks and supports fish or other aquatic life. This includes watercourses having a surface or subsurface flow that supports or has supported riparian vegetation.” 

• A designated creek corridor width should be based on the potential for riparian habitat and varies from creek to creek. Some definitions of creek corridor width depend on the observed creek profile and character of existing vegetation at a particular site. However, in a developed area, such a definition ignores prior destruction of riparian vegetation and the natural potential of an area. Where the designated creek corridor is narrower than the setback, property owners are encouraged to enhance riparian habitat in the setback.  

• Creek setback. Setbacks are generally measured from the top of the bank or from the creek centerline. The City of Oakland defines the setback as being measured back from the imaginary top of a 2:1 slope from the toe of the bank, a definition that more closely approximates a natural condition in alluvial soils. Such a definition also avoids depending on a movable and often artificial starting point; additionally, homeowners who grade back the creek bank could find themselves penalized as they have already increased the effective setback. The setback distance could vary from creek to creek, as established in a management plan. Development (e.g., buildings, impervious paving, swimming pools) should be prohibited within the setback. Varying setbacks could be established for different reaches of a creek depending upon the width of the riparian corridor, and potential (or lack of potential) for creek restoration.  

• The term “buffer” may be used to refer to a band of lightly used land between a defined creek corridor and the setback distance.  

• Uses that are allowed or disallowed within a designated zone must be defined. Improvements such as fences, paving, decks, hot tubs and ornamental plantings must be addressed.  

• Design review should be required in defined circumstances.  

• Variances may be permitted on improved properties, on small lots, and in irremediable situations; however, most situations should be addressed through the specific setback distance established for each creek.  

• The requirement to obtain permits from other regulatory agencies should be included. These agencies may include San Francisco Bay Regional Water Quality Control Board, California Department of Fish and Wildlife, Army Corps of Engineers, NOAA Fisheries, and the Coastal Commission.  

• Any new creekside project should include a survey of the riparian area and a study of the consequences of any alterations to grade, vegetation, or runoff.  

• Habitat enhancement should be encouraged or required as a condition of a permit. New vegetation should be maintained and monitored.  

• Tree protection policies should consider whether a species is native or not. Invasive non-native plant species such as bamboo, giant reed (Arundo), ivy and periwinkle (Vinca) should be prohibited from being planted within protected zones. Only native riparian species should be planted within the designated riparian corridor.  

• Fence design should be considered, to allow for wildlife passage and creek protection.  

• Surface runoff must be managed to increase infiltration and reduce erosion.  

• Best Management Practices for creekside construction should be defined.  

• Biotechnical techniques of bank stabilization should be required, when stabilization is necessary. Any other technique used must incorporate plantings, e.g., crib walls and riprap. Ideally, the bank is sloped back to a gentler grade.  

• Channel water-carrying capacity should be maintained.  

• Flood-plains should be enlarged where possible.  

• Vegetation removal and trimming for flood control purposes must be carried out only as each specific site requires to serve the purpose, following up-to-date practices.  

• Water diversions should be prohibited. Summer pools are critical habitat for young steelhead. 

Additional Guidelines

Other guidelines for creek protection can be found by contacting the following agencies or in the following documents: 

• Start at the Source Tools Handbook (2000), by San Francisco Bay Area Stormwater Management Agencies Association (BASMAA)  
• Marin County Stormwater Pollution Protection Program (MCSTOPPP).  
• California Department of Fish and Wildlife.  
• San Francico Bay Regional Water Quality Control Board.  
• Center for Watershed Protection, in Maryland, provides guidelines for urban areas  
• County of Marin: Stream Conservation Area Ordinance (draft 5/3/2013).  
• Fairfax: General Zone Regulations.  
• Novato: Waterway and Riparian Protection.  
• Oakland: Creek Protection, Stormwater Management and Discharge Control Ordinance.  
• Ross: Design Review Ordinance  
• City of Santa Cruz: City Wide Creeks and Wetlands Management Plan (2006), certified by the California Coastal Commission in 2008 
• The Handbook for Forest, Ranch and Rural Roads (2015), by Pacific Watershed Associates (PWA), available through the State Board of Forestry and Fire Protection or the State Water Resources Control Board.