Stormwater Trash Capture Compliance

The City of Gilroy is required to comply with the Statewide Trash Provisions under the Phase II Municipal Separate Storm Sewer System (MS4) Permit. The purpose of this mandate is to eliminate litter and trash from entering local waterways, including Uvas Creek, Llagas Creek, Miller Slough, and other open channels. 

The first compliance milestone requires the City to eliminate trash from 30% of Priority Land Use (PLU) areas by December 2, 2026, with additional milestones of 65% by 2028 and 100% by 2030.

Compliance is mandatory, and there is no dedicated state or federal funding for implementation. Costs are borne by the City.

To meet the December 2026 requirement, staff has recommended installation of 73 certified connector pipe screens (a type of full trash capture system) within Priority Land Use areas. This device is certified by the State Water Board and are designed to capture trash particles 5mm and larger before they enter the storm drain system.

 Metal connector pipe screen installed in a concrete stormwater inlet to capture debris Calm creek surrounded by dense fall foliage with trees reflecting on the water.

For future milestones (65% and 100% compliance), the City will evaluate additional options, including hydrodynamic separators and potential Track 2 compliance strategies.

The City has hired a contractor has hired to fabricate and install the 73 certified connector pipe screens.

In parallel, staff will:

  • Evaluate hydrodynamic separators as a potential long-term solution for higher compliance thresholds.
  • Assess the feasibility of Track 2 compliance for meeting the 65% and 100% milestones.
  • Develop future funding and implementation strategies based on Council direction.