San Diego Watershed Basin Study

Quick Links
Fact Sheet (PDF - 154 KB)

Task 2 Reports
Task 2.1 - Water Supply and Demand Projections Interim Report (March 2016) (PDF - 3.2 MB)
Task 2.2 - Climate Change Impacts and Hydrologic Modeling Final Report (May 2016) (PDF - 2.8 MB)
Task 2.3 - Existing Structural Response and Operations Guidelines Analysis (Aug 2017) (PDF - 6.9 MB)
Task 2.4 - Structural and Operational Concepts (PDF - 24.5 MB)
Task 2.5 - Trade-off Analysis and Recommendations
Task 2.6 - Final Report

Outreach Info

Oct. 24, 2018 Meeting Agenda (PDF - 89 KB)
Oct. 24, 2018 Presentation (PDF - 10 MB)

Jun. 27, 2018 Meeting Agenda (PDF - 92 KB)
Jun. 27, 2018 Presentation (PDF - 2.9 MB)

Aug. 2, 2017 Meeting Agenda (PDF - 134 KB)
Aug. 2, 2017 Presentation (PDF - 2 MB)

Nov. 7, 2014 Meeting Agenda (PDF - 31 KB)
Nov. 7, 2014 Presentation (PDF - 2.3 MB)

Feb. 2, 2016 Meeting Agenda (PDF - 59 KB)
Feb. 2, 2016 Presentation (PDF - 5.7 MB)

Other Southern California Basin Studies

In 2013, Reclamation collaborated with the City of San Diego Public Utilities Department (SDPUD) to study the potential utilization of local reservoirs within San Diego Basin for optimal storage of local, imported and purified water, as conceptualized in its 2012 Recycled Water Study.

SDPUD submitted a San Diego Watershed Basin Study (Study) proposal to Reclamation in March 2013 for a $2.1 million study. The Study is a 50-50 cost share partnership between SDPUD and Reclamation.  Reclamation funding was awarded in the amount of $1million, with a SDPUD cost share of $1,105,606 of which was provided by the State of California under a Proposition 50 grant and SDPUD.

map of San Diego watershed
The San Diego Watershed includes 3.1 million people and encompasses 2,900 square miles. Most of the people within the region inhabit the urbanized coastal areas, and the population of these areas is expected to increase by 30% by 2035, to over 4.0 million, according to San Diego Association of Governments (SANDAG) 2010 forecast.

SANDAG, a regional public planning organization, gathers and provides information on a broad range of topics that influence regional decision-making, including population changes and land use planning.

Imported water represents approximately 70-90% of the total water supply, and its reliability is uncertain.  Local water agencies are encouraged to develop local sources to ease the burden on the imported water sources. The region’s 11 sub-watersheds include the San Juan, Santa Margarita, San Luis Rey, Carlsbad, San Dieguito, Peñasquitos, San Diego, Pueblo, Sweetwater, Otay and Tijuana rivers.

The Study will use the latest change modeling tools to perform a quantitative analysis of the uncertainties associated with climate change impacts on the San Diego Basin’s local and imported fresh water supplies.  Accomplishment of the study objectives could assist water agencies serving the Basin and San Diego Integrated Regional Water Management planning region in adapting to climate change-related uncertainties and accomplishing the following:  

  • Improve the efficiency and effective use of existing structural systems, including reservoirs, and conveyance, treatment and Reclamation facilities.
  • Increase water supply reliability and resilience.
  • Address anticipated climate change impacts.
  • Increase accessibility of locally developed, advanced treated purified water.
  • Take advantage of potential energy management opportunities.
  •  Determine how climate change will impact the current and future water supply portfolio of the San Diego region.
Study Timeline
April 2016
Draft Interim Water Supply and Water Demand Projections Report
January 2016*
Draft Interim Climate Change and Hydrology Report
January 2017*
Draft Interim Existing Structural Response & Operations Guidelines Analysis Report
January 2017*
Draft Interim Structural and Operations Concepts Report
August 2017*
Draft Interim Trade-Off Analysis & Recommendations Report
April 2018*
San Diego Basin Study Completed
*Estimated draft interim completion dates

Send questions or comments via :

phone: (951) 695-5310
fax: (951) 695-5319

Last Updated: 12/18/18