Total Maximum Daily Loads (TMDLs)

Big Bear Lake, located in the San Bernardino Mountains, was created by the construction of the Bear Valley Dam in 1884. The Lake has a surface area of approximately 3,000 acres, a storage capacity of 73,320 acre-ft. and an average depth of 24 feet. The lake reaches its deepest point of 72 feet at the dam. The Big Bear Lake drainage basin encompasses 37 square miles and includes more than 10 streams. A TMDL for Total Phosphorus was adopted for dry hydrological conditions at Big Bear Lake on April 21, 2006. It was then approved by The Office of Administrative Law (OAL) on August 21, 2007 followed by the US Environmental Protection Agency (USEPA) on September 25, 2007. More information including the Implementation Plan can be found in Chapter 6 of the Santa Ana Water Board Basin Plan. Contact: Terri Reeder

The Middle Santa Ana River watershed covers approximately 488 square miles and lies largely in the southwestern corner of San Bernardino County, and the northwestern corner of Riverside County. A small part of Los Angeles County (Pomona/Claremont area) is also included. This watershed is comprised of three sub–watersheds. TMDLs for indicator bacteria were adopted on August 26, 2005 for the Middle Santa Ana River Watershed through Resolution R8-2005-0001. They were then approved by the Office of Administrative Law (OAL) on September 1, 2006 followed by the US Environmental Protection Agency on (US EPA) May 16, 2007. More information can be found in Chapter 6 of the Santa Ana Water Board Basin Plan. Contact: Terri Reeder

Notice of Public Hearing

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Notice for public comment

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Scientific Peer Review Responses to Comments

Lake Elsinore Canyon Lake nutrient TMDLs
The Lake Elsinore/San Jacinto River watershed is located in Riverside County and includes the following major waterbodies: Lake Hemet, San Jacinto River, Salt Creek, Canyon Lake and Lake Elsinore. The total drainage area of the San Jacinto River watershed is approximately 782 square miles. Over 90 percent of the watershed (735 square miles) drains into Canyon Lake. Lake Elsinore is the terminus of the San Jacinto River watershed. TMDLs for nutrients were adopted on December 20, 2004 for Lake Elsinore and Canyon Lake through Resolution R8-2004-0037. They were then approved by the US Environmental Protection Agency on (US EPA) September 30, 2005. More information can be found in Chapter 6 of the Santa Ana Water Board Basin Plan.

The TMDLs are currently being reconsidered – proposed revisions to the Lake Elsinore Canyon Lake nutrient TMDLs
Contact: Terri Reeder

The Newport Bay watershed is located in Central Orange County in the southwest corner of the Santa Ana River Basin, about 35 miles southeast of Los Angeles and 70 miles north of San Diego (Appendix 1). The watershed encompasses 154 square miles and includes portions of the Cities of Newport Beach, Irvine, Laguna Hills, Lake Forest, Tustin, Orange, Santa Ana, and Costa Mesa. Mountains on three sides encircle the watershed; runoff from these mountains drains across the Tustin Plain and enters Upper Newport Bay via San Diego Creek. Newport Bay is a combination of two distinct water bodies - Lower and Upper Newport Bay, divided by the Pacific Coast Highway (PCH) Bridge. The Lower Bay, where the majority of commerce and recreational boating exists, is highly developed. The Upper Bay contains both a diverse mix of development in its lower reach and an undeveloped ecological reserve to the north, the 752-acre Upper Newport Bay Ecological Reserve and Nature Preserve, which is also a State Marine Protected Area. The watershed includes three freshwater subwatersheds (San Diego Creek, Santa Ana - Delhi Channel, and Big Canyon Wash), and two smaller freshwater tributaries, (Costa Mesa and Santa Isabel channels), all of which discharger directly into Upper Newport Bay. Contact: Terri Reeder

(Note: Basin Plan amendments for the Newport Bay watershed TMDLs for Selenium, Organochlorines Compounds, Nutrients, and Sediment can be found in Chapter 6 of the Water Quality Control Plan for the Santa Ana River Basin.)

Fecal Coliform TMDLs for Newport Bay

The Santa Ana Water Board adopted a Basin Plan amendment for the Fecal Coliform TMDLs for Newport Bay on June 3, 2022 at a public hearing, which was subsequently approved by the State Water Board on November 15, 2022 and the Office of Administrative Law on June 15, 2023. The Basin Plan amendment extends the deadline for attainment of the water quality objectives (WQOs) for the shellfish beneficial use (SHEL) in Newport Bay, from December 31, 2022, to December 31, 2030. The purpose of the extension is to allow additional time to complete studies that are currently in progress to determine whether there is a correlation between fecal indicator bacteria in water and fecal indicator bacteria and pathogens in shellfish tissue. A dry season study of bacteria in the water column and bacteria in shellfish was completed by the Southern California Coastal Water Research Project (Technical Report 1193). The study found no correlation between the SHEL WQOs in water and bacteria and pathogen levels in Pacific oysters in Newport Bay. A similar study for the wet season is currently underway.

Resolution No. R8-2022-0017
Basin Plan Amendment
Staff Report
Response to Comments
Executive Officer Correction Memo

Time Schedule Order Number R8-2019-0050 for the County of Orange, the Orange County Flood Control District, and the Cities of Tustin, Irvine, Laguna Hills, Laguna Woods, Costa Mesa, Santa Ana, Orange, Lake Forest and Newport Beach to comply with the Requirements Prescribed in Order Number R8-2009-0030 as amended by Order Number R8-2010-0062 (NPDES Permit Number CAS618030)

Copper TMDLs

TMDLs for Copper in Newport Bay were approved by the Santa Ana Water Board at the December 2, 2022 public hearing. Water Board staff are working on additional public outreach as required by AB 2108 in preparation for consideration of adoption of the Cu TMDLs by the State Water Board in 2023. For updates, Subscribe to the E-mail Notification List (Select "TMDL Newport Bay Copper - Metals").

Notice of State Water Board Public Comment Period, Newport Bay Copper TMDLs. In accordance with the State Water Resources Control Board's (State Water Board) Notice of Opportunity for Public Comment (available in English, Spanish/Español, and Traditional [Mandarin] Chinese/繁體中文"到繁體) on the Newport Bay Copper TMDLs, the Basin Plan amendment and supporting documents are available for public comment prior to scheduling a public meeting for consideration of approval by the State Water Board. The Santa Ana Water Board adopted the Basin Plan amendment on December 2, 2022, by Resolution R8-2022-0012.Please note that the end of the Public Comment period for the Newport Bay Copper TMDLs Basin Plan amendment and supporting documents has been revised: Written comments are now due at 12 noon on July 17, 2023.
Basin Plan Amendments for Copper (Cu) TMDLs for Regional Board Hearing - December 2, 2022

• Basin Plan Amendment (BPA) Cu TMDLs - Attachment A to Resolution 2022-0012
• Substitute Environmental Document (SED) -Cu TMDLs
• Staff Report - Cu TMDLs -SED Appendix A
• SED Appendix B-1a Responses to 2016 Comments Document (2018)
• SED Appendix B-1b Responses to 2016 Board Meeting Comments Document (2021)
• SED Appendix B-2 Responses to August 2018 Comments Document (2021)
• SED Appendix B-3 Responses to 2019 Workshops Comments Document (2021)
• SED Appendix B-4 Responses to August 2021 Comments- Cu TMDLs (2022)
• SED Appendix B-5 Responses to County-City Alternative Implementation Proposal
• Notice of Public Hearing & Filing (October 18, 2022)