Erosion and Sediment Management


Gullies are common erosional features in San Mateo County, and can deliver significant amounts of sediment to local coastal creeks and streams where excess sediment harms habitat for fish and other aquatic species. For landowners gullies can cause loss of grazing or farm land, and undermine roads, fencing and other infrastructure. Addressing gully erosion with appropriate conservation practices and treatments helps landowners and improves conditions for aquatic species.

In 2017 the RCD completed an assessment of the relative significance of gullies in supplying sediment to coastal creeks in the Pescadero-Butano Watershed. The assessment examined causes and characteristics of gully erosion, and identified and prioritized solutions. The RCD has since updated this report to include an assessment of gully erosion following the heavy precipitation winter of 2016-2017 which could not be captured in the initial (2017) analysis. Findings from this report help the RCD recommend conservation practices to prevent future, and address existing gully erosion in the Conservation and Carbon Farm Plans that RCD develops.

Report: Coastal San Mateo County Gully Erosion Report *UPDATED* (2021)


  • NRCS
  • Landowners
  • Regional Water Quality Control Board

RCD Contact: Sara Polgar