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Engineering | Finance | Administrative

The Basin. Click to see larger!The Chino Basin is one of the largest groundwater basins in Southern California containing approximately 5,000,000 acre-feet of water and has an unused storage capacity of approximately 1,000,000 acre-feet. The Chino Basin consists of approximately 235 square miles of the upper Santa Ana River watershed and lies within portions of San Bernardino, Riverside, and Los Angeles counties. Approximately 5% of the Chino Basin is located in Los Angeles County, 15% in Riverside County, and 80% in San Bernardino County. The Chino Basin is bounded by Cucamonga Basin and the San Gabriel Mountains to the north, the Temescal Basin to the south, Chino Hills and Puente Hills to the southwest, San Jose Hills, Pomona and Claremont Basins on the northwest and the Rialto/Colton Basins on the east. The legal boundaries of the Chino Basin are defined in the Judgment.

The Chino Basin has a rapidly growing population. As of August 1, 2001, the population of the Chino Basin was approximately 1.2 million, and estimated to reach approximately 1.6 million or more by 2020. Consequently, the demand for water from the Chino Basin is expected to continue to rise, and thus conservation and efficient use of the Chino Basin water supply is crucial to meeting future water demands. In the 1970s, Chino Basin water users became concerned with increasing water production, a decreasing water supply and declining water quality in the Chino Basin. By 1975, several major Chino Basin water users and the State of California initiated studies of problems allocating water rights within the Chino Basin, and began to negotiate a solution. During negotiations, three pools of Chino Basin water users with similar interests in the allocation of the Chino Basin emerged: (i) agricultural users, including dairy farmers and the State of California (the "Agricultural Pool"), (ii) industrial users (the "Non-Agricultural Pool"), and (iii) water municipalities (the Appropriative Pool) and other government entities sometimes collectively referred to herein as the "Pools" and each individually as a "Pool").

On January 2, 1975, several Chino Basin producers filed suit in California State Superior Court for San Bernardino County (the "Court") to settle the problem of allocating water rights in the Chino Basin. On January 27, 1978, the Court entered a judgment in "Chino Basin Municipal Water District v. City of Chino et. al." adjudicating water rights in the Chino Basin and establishing the Watermaster (the "Judgment"). The Watermaster is a Court created entity established pursuant to the Judgment. The Judgment adjudicated all groundwater rights in Chino Basin and contains a physical solution to meet the requirements of water users having rights in or dependent upon the Chino Basin. The judgment also appointed the Watermaster to account for and implement the management of the Chino Basin. The Judgment declared that the initial operating safe yield of the Chino Basin is 145,000 acre feet per year, which is allocated (i) 82,800 acre feet per year to the Agricultural Pool, (ii) 7,366 acre feet per year to the Non-Agricultural Pool, and (iii) 54,834 acre feet per year to the Appropriative Pool.


Watermaster continues to develop the Optimum Basin Management Program (OBMP). Upon completion of the OBMP, specific tasks and activities were assigned to Watermaster's legal and engineering services to support Watermaster in the implementation of the OBMP. The OBMP consists of nine key elements covering a wide-range of water activity in the Basin. More...


Watermaster Administration is based on day-to-day operations and extensive communication to meet requirements of the judgment and the court. The efficiency and effectiveness of daily operations consist of staff resources to support the Watermaster Board, Advisory Committee, Non-Agricultural Pool, Appropriative Pool, and Agricultural Pool. In an effort to build and develop a strong administrative foundation, Watermaster is required to facilitate the appropriate supporting documentation referencing all water activities involving Watermaster. More...


The main Source of Revenue for the Watermaster are Assessments. The Watermaster levies and collects Administrative Assessments, OBMP Assessments, and Replenishment Assessments. Administrative Assessments are general administrative and special project expenses incurred by Watermaster. These administrative expenses are allocated and assessed to the respective pools based on allocations made by Watermaster. Special project expenses are allocated to the specific pool by express assent and findings of benefits by the applicable pool committee, or pursuant written order of the court. More...

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Chino Basin Watermaster 9641 San Bernardino Road, Rancho Cucamonga, CA 91730
Phone: 909-484-3888   Fax: 909-484-3890

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