The California Water Boards' Annual Performance Report - Fiscal Year  2016-17 

MEASUREMENTS  - Data Last Updated on: 

WHAT THE MEASURE IS SHOWING

WHY THIS MEASURE IS IMPORTANT

TECHNICAL CONSIDERATIONS

• Data Source: CIWQS. Period July 1, 2015 to June 30, 2016.
• Unit of Measure: Number of active MS4 facilities during FY 15-16.
• Data Definitions: Permits Active as of June 30, 2015.
• References: Information on the Water Boards’ NPDES Storm Water Program
  Public Reports and Data
  Enforcement and Compliance Assurance Information

GLOSSARY

Municipal Storm Water Phase I Facilities

The Municipal Storm Water Permits regulate storm water discharges from municipal separate storm sewer systems (MS4s). Under Phase I, which began in 1990, the Regional Water Boards have issued NPDES MS4 permits to permittees serving populations greater than 100,000 people. Many of these permits are issued to a group of co-permittees encompassing an entire metropolitan area. These permits are reissued as the permits expire.

Municipal Storm Water Phase II Facilities

Under Phase II, the State Water Board adopted a General Permit for the Discharge of Storm Water from Small MS4s (WQ Order No. 2013-0001-DWQ) to provide permit coverage for smaller municipalities (10,000 to 100,000 people), including non-traditional small MS4s which are governmental facilities such as military bases, public campuses, prisons and hospital complexes.

( Page last updated:  11/1/17 )