Quantification Settlement Agreement

The Quantification Settlement Agreement for the Colorado River was completed in October 2003. This historic agreement provides California the means to implement water transfers and supply programs that will allow California to live within the state's 4.4 million acre-foot basic annual apportionment of Colorado River water.


The QSA is a major achievement for enhancing San Diego County's long-term water supply reliability. Supplies related to the accord now account for nearly 38 percent of our region's water and they will continue to grow in the years ahead.

The QSA commits a Joint Powers Authority (QSA JPA), to mitigate for any negative impacts to the Salton Sea caused by these water supply programs. It also commits the state to a restoration plan, called the Salton Sea Management Program (SSMP), which will provide a path forward for any impacts to the Salton Sea caused outside of the QSA, and any impacts beyond what is required of the QSA JPA. The SSMP will guide investments at the Salton Sea to protect public health and ecosystem wealth.

A major supply source secured for San Diego under the QSA is the Water Authority-Imperial Irrigation District Water Transfer, which will provide up to 200,000 acre feet of water to the region by 2020.


The Parties

Statewide Benefits

1. Reduces California's over-dependence on Colorado River — the QSA enables California to reduce its historic over-dependence on the Colorado River to its 4.4 million acre-foot basic annual apportionment through voluntary agriculture-to-urban water transfers and other water supply programs.

2. Salton Sea Restoration — As part of the QSA legislation enacted in October 2003, the state of California is obligated to undertake the restoration of the Salton Sea ecosystem. Click here for more information on the Salton Sea.

3. Voluntary agricultural transfers provide more than 30 million acre-feet for urban use — Over the life of the QSA programs, more than 30 million acre-feet moves from primarily agricultural use to primarily urban use.

Imperial Valley Outreach Office
Click here to contact the Water Authority's Imperial Valley Outreach Office

Litigation Challenging QSA Defeated

The QSA has held up to scrutiny under several unsuccessful legal challenges in state and federal court. In 2014, for instance, a three-judge panel of the 9th U.S. Circuit Court of Appeal upheld a District Court ruling that the Secretary of the Interior did not violate the National Environmental Policy Act or the Clean Air Act in approving the Colorado River Water Delivery Agreement. 

9th U.S. Circuit Court of Appeals Ruling – May 19, 2014

QSA Judgments - July 31, 2013

QSA Ruling - June 4, 2013

QSA Documents in PDF

icon_pdf.pngQSA Fact Sheet

icon_pdf.pngQuantification Settlement Agreement October 10, 2003

Agreements to which the San Diego County Water Authority are signatories include:

Regarding Implementation of Conservation and Mitigation Measures Identified in the USFWS Biological Opinion Dated January 12, 2001, “For Interim Surplus Criteria, Secretarial Implementation Agreements, and Conservation Measures on the Lower Colorado River, Lake Mead to the Southerly International Boundary Arizona, California and Nevada