State Stormwater Permits

Welcome to the City of Watsonville’s Stormwater and Wastewater Permit System

Understanding and following appropriate permits help prevent stormwater and wastewater pollution. Learn more about permit requirements below.

Stormwater Permit

The City’s storm drain system is designed to prevent floods and only rain water should flow through them. However, when water flows out of our yards, down driveways, out parking lots and into the storm drains, it makes its way through the environment, untreated. Storm drains are not connected to the sewer system; instead they drain directly into our waterways. Watsonville storm drains lead to our local wetlands, creeks and the Pajaro River, which eventually enter the Monterey Bay.

Industrial/General Permit

The Industrial Stormwater General Permit Order 97-03-DWQ is regulated by the National Pollutant Discharge Elimination System (NPDES) and covers the discharges associated with ten broad categories of industrial activities. The General Industrial Permit requires the implementation of management measures that will achieve the performance standard of best available technology economically achievable (BAT) and best conventional pollutant control technology (BCT). The General Industrial Permit also requires the development of a Stormwater Pollution Prevention Plan (SWPPP) and a monitoring plan. Through the SWPPP, sources of pollutants are to be identified and the means to manage the sources to reduce stormwater pollution are described.

The National Pollutant Discharge Elimination System (NPDES) stormwater program requires construction site operators engaged in clearing, grading, and excavating activities that disturb one acre or more, including smaller sites in a larger common plan of development or sale, to obtain coverage under an NPDES permit for their stormwater discharges.

Municipal Permit

The Municipal Phase II MS4 Permit is an NPDES (National Pollution Discharge Elimination System) Permit that was established under the Federal Clean Water Act of 1972.  The Phase II Municipal General Stormwater Permit (2013-0001-DWQ) regulates discharges from municipal storm drain systems with populations less than 100,000. The regulation requires the City to oversee a variety of activities within the City; including: public education about pollution prevention, good housekeeping for municipal projects and implementation of best management practices throughout the City.

Erosion Control Resources

In addition to NPDES program local City Ordinances require construction site stormwater management for smaller projects. Construction site stormwater management is also known as erosion control.

A new Erosion and Sediment Control Plan is now required for all building and grading permits where a soil disturbance will be created (there is no minimum project size.) This is all part of a State reporting requirement that the City of Watsonville must report on. Below is a link to the Erosion and Sediment Control Plan (ESCP) that must be filled out.

The City of Watsonville enacted new post construction requirements for managing storm runoff from new development and redevelopment projects. The new regulations closely follow the requirements adopted by the Central Coast Regional Water Quality Board on July 12, 2013.

City Ordinance and State and Federal regulations require construction site stormwater management also known as erosion control. The San Francisco Public Utilities Commission Construction Best Management Practices Handbook provides resources for developers, architects and engineers as well as contractors.

The handbook provides information on the following Construction Best Management Practices: Construction site planning and management, vehicle tracking and dust control, erosion and sediment control, non-stormwater and water/material management.

Low Impact Development

Low Impact Development (LID) is a leading stormwater management strategy that seeks to mitigate the impacts of runoff and stormwater pollution as close to its source as possible. Urban runoff discharged from municipal storm drain systems is one of the principal causes of water quality impacts in most urban areas. It can contain pollutants such as trash and debris, bacteria and viruses, oil and grease, sediments, nutrients, metals, and toxic chemicals that can negatively affect the ocean, rivers, plant and animal life, and public health.

LID comprises a set of site design approaches and best management practices (or BMPs) that are designed to address runoff and pollution at the source. These LID practices can effectively remove nutrients, bacteria, and metals while reducing the volume and intensity of stormwater flows.

The City of Watsonville’s LID ordinance became effective in February 27, 2014. The main purpose of the new regulations is to ensure that development and redevelopment projects manage their runoff at their construction location.  The new regulations which promote and encourage the use of low impact development are known as the city’s Post Construction Ordinance.


Encroachment/Engineering Permits required by the City’s Community Development Department best management practices on construction sites and post-construction sites. These measures are revised during the design phase and permitting phase and during post-construction inspections.