Water Quality

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Pillar Point Harbor and Venice Beach Bacteria TMDL

The State Water Board adopted Resolution No. 2021-0026 approving the Basin Plan amendment to establish the Bacteria TMDL and to update the bacteria objectives in the Basin Plan on July 20, 2021.


The City of Half Moon Bay, in partnership with The County of San Mateo and San Mateo County Harbor District, are working to improve creek and beach water quality here on the Coastside. Some of the ways we are working to accomplish this is by inspecting and maintaining our stormwater infrastructure, increasing access to public restrooms and pet waste stations to keep waste from entering our waterways, and monitoring the bacteria levels at our beaches.  

TMDL watershed map

Project Location:

The Pillar Point Harbor and Venice Beach Bacteria TMDL project location consists of multiple watersheds ranging from north of the Pillar Point Harbor to south of Half Moon Bay State Beach. Pillar Point Harbor drains approximately 3,920 acres and includes inflows from the Denniston, St. Augustine, and Deer Creek watersheds, which comprise open space, an airport, and agricultural, commercial, and residential areas. Venice Beach is one of the five interconnected beaches comprising the Half Moon Bay State Beach The approximately 0.8-mile stretch of Venice Beach is abutted by Frenchmans Creek to the north and Pilarcitos Creek to the south. These two creeks drain approximately 21,120 acres of watershed, which is predominantly open space with residential and commercial areas in the lower watershed close to the beach. Small farms are scattered along Pilarcitos Creek where it follows Highway 92. These creeks sometimes breach the beach and flow into the ocean, providing a conduit for stormwater runoff from the surrounding watersheds.

Sources of Bacteria Diagram

Dog poop can be a significant source of bacteria, as a single dog produces more bacteria in one day than a person, a horse and a cow combined. When it rains, bacteria and organisms in dog waste flow to nearby waterways and beaches, and contaminate water used by swimmers, surfers, and sea life. The Pet Waste Education and Outreach program is in partnership with the County and includes dog waste cleanup events, school programs, flyers, social media, newsletters, and tabling at events to educate the community about the impacts of pet waste on our waterways.

Why does this matter? According to the EPA, pet waste contains bacteria that threaten the health of animals and people, especially children. Diseases that can be transmitted from pet waste include salmonellosis, toxocariasis, and toxoplasmosis. Not picking up after your dog can have some sickly consequences for beach-goers and aquatic animals alike. Bacteria and parasites in dog waste can be transmitted to humans through contaminated soil, water, or even through direct contact. Children who play in parks or streams have an even greater risk of coming in contact with these diseases.

Take the Scoop-the-Poop pledge and receive a free dog bag bag dispenser at flowstobay.org/petwaste.