San Diego Creek Water Rights License

San Diego Creek Water Rights License

San Diego Creek Water Rights License Application Process 

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IRWD is converting the San Diego Creek Water Rights Permit into a Water Rights License. Securing this license will ensure that IRWD can keep diverting water from the creek into the San Joaquin Marsh to treat and then return it to the creek.  Treating the water in the Marsh helps keep the Newport Bay clean and provides valuable wildlife and habitat benefits.



The IRWD San Joaquin Marsh (Marsh) consists of 274 acres of land adjacent to San Diego Creek in Irvine. Since 1997, the Marsh has been an integral part of the successful Natural Treatment System (NTS), a watershed wide system of natural treatment ponds which are used to treat dry weather runoff.

A major source of water in San Diego Creek is urban runoff. To treat the contaminated urban runoff, water from San Diego Creek is diverted into the Marsh and run through a series of constructed water quality wetlands and ponds where nitrogen, phosphorus and bacteria are naturally removed before the water is returned to San Diego Creek and eventually reaches ecologically sensitive Upper Newport Bay.


SJM Natural Treatment system  

Fig. 1: San Joaquin Marsh Natural Treatment System



Environmental Stewardship

Cleaning urban runoff has environmental water quality and habitat benefits. Benefits associated with the Marsh include:

  • Treatment of over 1 billion gallons of urban runoff annually;
  • 85% removal of nitrogen and 100% removal of phosphorus loads into the Newport Bay State Ecological Reserve;
  • 99% reduction of Coliform bacteria;
  • 79% reduction of selenium and 59% reduction of copper loads into Newport Bay State Ecological Reserve; and
  • Creation of major riparian and wetland habitat which supports over 282 species of migratory birds, including several state and federally listed species.


Why is IRWD Treating Urban Runoff?

Treating urban runoff is one of IRWD's core responsibilities. Section 35539.12 of the California Water Code grants IRWD the authority to construct, maintain and operate urban runoff treatment facilities within the service area. The Natural Treatment System also provides riparian habitat and water-quality benefits to wildlife throughout the watershed.


San Diego Water Creek Water Rights Permit

In 1997, IRWD received authorization from the State Water Resources Control Board to divert and use water from San Diego Creek for wildlife enhancement and irrigation of habitat within constructed treatment wetlands of the Marsh. The construction of the Marsh was completed in 1998 and since this time, IRWD has been diverting water from San Diego Creek for treatment within the Marsh.

Under SCRCB Permit 20979, IRWD has established the right to divert 3,600 acre-feet of water per year at a rate of 5 cubic feet per second to treat the water for the beneficial uses of wildlife and habitat enhancement. After the diverted water flows through the treatment ponds, treated water (which is cleaner than water in the creek) is returned to San Diego Creek.


What is the difference between a Water Right Permit and a Water Right License?

The California State Water Resources Control Board states that “a water right permit is an authorization to develop a water diversion and use project. The right to use water is obtained through actual use of water within the limits described in the permit.” After a water right permit is received, the project is constructed and water is used, the SWRCB will inspect the project. If water has been beneficially used and if all conditions of the permit have been met, a water right license may be obtained. The water right license is a vested right that confirms the actual use of the water.


Why is IRWD Applying for a Water Rights License for San Diego Creek?

The procedure established by the California State Water Resources Control Board for establishing a water right is to first apply for a Water Right Permit (as outlined in the paragraph above). After this is established, the next step is to apply for a Water Rights License.  Inasmuch as IRWD has successfully demonstrated the wildlife and habitat enhancement/beneficial uses of the water diverted from San Diego Creek as required, IRWD is following the SWRCB procedure and applying to change the Water Rights Permit into a Water Rights License. The Water Rights License application will not change the amount of water than can be diverted, it does not increase IRWD’s water demands from San Diego Creek, and it does not alter the operations of the Marsh.


IRWD San Diego Creek Water Permit Modifications

IRWD has been successfully operating the Marsh for almost twenty years. Before submitting the application for a Water Rights License, IRWD will be submitting some minor changes to the Water Right Permit that better reflect the actual operations at the Marsh. In bureaucratic language, the vehicle for these minor modifications is called a Change Petition. Once approved, the Change Petition will be incorporated into the Water Rights License application.


The Change Petition to Water Rights Permit 20979

The Change Petition will not change the beneficial uses, or the amount of water diverted from San Diego Creek, that are authorized by the original Permit 2097. Specifically the Change Petition to the Water Rights Permit include the following minor changes (more specifics are available here):

  1. Place of Use: In addition to the current 140-acres of permitted area of use, the Permit would incorporate the broader Marsh which includes other riparian mitigation areas and the University of California Natural Reserve System (UCNRS) marsh, totaling 500 acres. This will allow IRWD more flexibility to provide water to the UCNRS marsh, as available, without increasing diversions from San Diego Creek. This reflects a current use of the diversion.

  1. Completion Date: The Permit specifies a development schedule for IRWD to complete the construction of the Marsh and establish the beneficial use of diverted water by December 31, 2007. Revising this date to December 31, 2020 will support licensing of the Permit.

Download this information as a PDF file:  click here 

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