Santa Clara County's Watershed Protection Division

The mission of the Watershed Protection Division is to protect the creeks and rivers of the Monterey Bay and San Francisco Bay watersheds by fostering best practices in County operations, promoting increased public awareness of stormwater pollution prevention, and supporting innovative approaches to meet state and federal stormwater regulations.

What We Do

Santa Clara County's Watershed Protection Division (WPD) protects local waterways like creeks and rivers, and the reservoirs and bays by preventing pollution from stormwater runoff. We use an integrative approach to achieve water quality and environmental protection. 

Through our work, we:

  • Provide outreach and education to the public, local businesses, and County departments on the importance of stormwater pollution prevention;
  • Coordinate County compliance with federal and state-mandated water quality permits, including a Municipal Regional Stormwater NPDES Permit for the San Francisco Bay watershed and a Phase II NPDES Permit for the Monterey Bay watershed;
  • Provide oversight of area waterway studies, and assure completion of monitoring and compliance reporting to regulatory agencies;
  • Assure that construction and development activities throughout the unincorporated areas of the County are carried out with strict adherence to water quality regulations, including effective erosion and sediment control practices during construction, and proper stormwater management and pollution prevention post- construction; and
  • Encourage adoption of new approaches toward maintaining water quality standards by seeking innovative methods of protecting our local water resources.​


The WPD was established to provide protection of our waterways through proper construction practices, public outreach, and permit implementation, coordination and reporting. WPD staff is responsible for ensuring the County’s compliance with federal and state water quality requirements by promoting stormwater pollution prevention practices, erosion and sediment control, and landscape features that filter pollutants from stormwater runoff. We achieve this by assuring that all surface water draining into our County’s major waterways meets the Water Quality Standards defined by the federal Clean Water Act.

We use a collaborative approach, working in conjunction with 76 co-permittees in the San Francisco Bay watershed, with SCVURPPP and BASMAA, and with the cities of Morgan Hill and Gilroy in the Pajaro River and Monterey Bay watershed. Additionally, we work with local businesses, homeowners, and environmental stewardship organizations to minimize pollutants in stormwater runoff. 

We implement two permits under the National Pollutant Discharge Elimination System (NPDES) within unincorporated Santa Clara County.

NPDES Stormwater Permits

Santa Clara County, as well as all municipalities, must maintain a NPDES permit to prevent the discharge of pollutants into Municipal Separate Storm Sewer Systems (MS4s). We have two different NPDES Permits: 

  • Phase I NPDES Permit: Designed for populations of 100,000+.
  • Phase II NPDES Permit: Municipalities and regions of under 100,000.

Both permit types include requirements for the following:

  1. Public Education and Outreach
  2. Illicit Discharge Detection and Elimination
  3. Construction and Post-Construction Requirements
  4. Good Housekeeping Practices for Municipal Operations

In California, Regional Water Quality Control Boards (RWQCB) are authorized to issue NPDES Permits, which are determined based on the major bodies of water within their domain. The San Francisco RWQCB (Region 2) monitors waters discharging to San Francisco Bay, and The Central Coast RWQCB (Region 3) monitors waters discharging to the Monterey Bay and Central Coast. Because of Santa Clara County’s unique geology and topography, water in the South County (south of Cochrane Road at Highway 101) drains to the Pajaro River and Monterey Bay, and water in the North County drains to San Francisco Bay. As a result, our county maintains two NPDES permits under both RWQCBs.​​​​​ ​​

San Francisco Bay and Monterey Bay Watersheds and NPDES Area Boundaries

Related Resources

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