The County and cities of south Orange County are subject to a municipal separate storm sewer system permit (MS4 Permit) issued by the San Diego Regional Water Board (Water Board) which regulates the discharge of stormwater runoff from urbanized areas. On January 31, 2018, these municipalities collectively submitted to the Water Board a Transitional Monitoring & Assessment Report (TMAR) which assesses stormwater runoff from the urbanized areas of south Orange County between October 1, 2016, and September 30, 2017. Click here to review the 2016-17 TMAR for the South OC Watershed Management Area.
