CHAPTER 1. General State Policy [100. - 113.]

Cal. Water Code - WAT 1.

in effect

Cal. Water Code - WAT § 100. Section 100.

It is hereby declared that because of the conditions prevailing in this State the general welfare requires that the water resources of the State be put to beneficial use to the fullest extent of which they are capable, and that the waste or unreasonable use or unreasonable method of use of water be prevented, and that the conservation of such water is to be exercised with a view to the reasonable and beneficial use thereof in the interest of the people and for the public welfare. The right to water or to the use or flow of water in or from any natural stream or watercourse in this State is and shall be limited to such water as shall be reasonably required for the beneficial use to be served, and such right does not and shall not extend to the waste or unreasonable use or unreasonable method of use or unreasonable method of diversion of water.

Cal. Water Code - WAT § 100.5. Section 100.5.

It is hereby declared to be the established policy of this state that conformity of a use, method of use, or method of diversion of water with local custom shall not be solely determinative of its reasonableness, but shall be considered as one factor to be weighed in the determination of the reasonableness of the use, method of use, or method of diversion of water, within the meaning of Section 2 of Article X of the California Constitution.

Cal. Water Code - WAT § 101. Section 101.

Riparian rights in a stream or watercourse attach to, but to no more than so much of the flow thereof as may be required or used consistently with this and the next preceding section, for the purposes for which such lands are, or may be made adaptable, in view of such reasonable and beneficial uses; provided, however, that nothing in this or the next preceding section shall be construed as depriving any riparian owner of the reasonable use of water of the stream to which his land is riparian under reasonable methods of diversion and use, or of depriving any appropriator of water to which he is lawfully entitled.

Cal. Water Code - WAT § 102. Section 102.

All water within the State is the property of the people of the State, but the right to the use of water may be acquired by appropriation in the manner provided by law.

Cal. Water Code - WAT § 103. Section 103.

In the enactment of this code the Legislature does not intend thereby to effect any change in the law relating to water rights.

Cal. Water Code - WAT § 104. Section 104.

It is hereby declared that the people of the State have a paramount interest in the use of all the water of the State and that the State shall determine what water of the State, surface and underground, can be converted to public use or controlled for public protection.

Cal. Water Code - WAT § 105. Section 105.

It is hereby declared that the protection of the public interest in the development of the water resources of the State is of vital concern to the people of the State and that the State shall determine in what way the water of the State, both surface and underground, should be developed for the greatest public benefit.

Cal. Water Code - WAT § 106. Section 106.

It is hereby declared to be the established policy of this State that the use of water for domestic purposes is the highest use of water and that the next highest use is for irrigation.

Cal. Water Code - WAT § 106.3. Section 106.3.

(a) It is hereby declared to be the established policy of the state that every human being has the right to safe, clean, affordable, and accessible water adequate for human consumption, cooking, and sanitary purposes. (b) All relevant state agencies, including the department, the state board, and the State Department of Public Health, shall consider this state policy when revising, adopting, or establishing policies, regulations, and grant criteria when those policies, regulations, and criteria are pertinent to the uses of water described in this section. (c) This section does not expand any obligation of the state to provide water or to require the expenditure of additional resources to develop water infrastructure beyond the obligations that may exist pursuant to subdivision (b). (d) This section shall not apply to water supplies for new development. (e) The implementation of this section shall not infringe on the rights or responsibilities of any public water system.

Cal. Water Code - WAT § 106.4. Section 106.4.

(a) For the purposes of this section: (1) “Bottled water” has the same meaning as defined in Section 111070 of the Health and Safety Code. (2) “Residential development” has the same meaning as defined in Section 65008 of the Government Code. (3) “Retail water facility” has the same meaning as defined in Section 111070 of the Health and Safety Code. (4) “Water-vending machine” has the same meaning as defined in Section 111070 of the Health and Safety Code. (5) “Water hauler” has the same meaning as defined in Section 111070 of the Health and Safety Code. (b) A city, including a charter city, or a county shall not issue a building permit for the construction of a new residential development where a source of water supply is water transported by a water hauler, bottled water, a water-vending machine, or a retail water facility. (c) This section does not apply to a residence that will be rebuilt because of a fire or natural disaster. (d) The Legislature finds and declares that this section addresses a matter of statewide concern and not a municipal affair, as that term is used in Section 5 of Article XI of the California Constitution.

Cal. Water Code - WAT § 106.5. Section 106.5.

It is hereby declared to be the established policy of this State that the right of a municipality to acquire and hold rights to the use of water should be protected to the fullest extent necessary for existing and future uses, but that no municipality shall acquire or hold any right to waste water, or to use water for other than municipal purposes, or to prevent the appropriation and application of water in excess of its reasonable and existing needs to useful purposes by others subject to the rights of the municipality to apply such water to municipal uses as and when necessity therefor exists.

Cal. Water Code - WAT § 106.7. Section 106.7.

(a) It is hereby declared to be the established policy of this state to support and encourage the development of environmentally compatible small hydroelectric projects as a renewable energy source, provided that the projects do not result in surface disturbances within the following sensitive areas: (1) Any component of the California Wild and Scenic Rivers System or the National Wild and Scenic Rivers System. (2) Any river designated for study pursuant to Section 5(a) of the National Wild and Scenic River Act (16 U.S.C. 1276(a)). This paragraph shall not apply to any river which, upon the completion of the study, is not included in the National Wild and Scenic Rivers System. (3) Any state or federally designated wilderness area. (4) Any areas designated as a “Critical Condor Habitat” by the United States Fish and Wildlife Service. (b) State agencies shall not approve small hydroelectric development within the sensitive areas specified in subdivision (a). (c) Significant adverse impacts associated with small hydroelectric projects shall be identified by those agencies responsible for the preparation of the environmental impact document. (d) Emphasis on the development of small hydroelectric power generating facilities which are “qualifying small power production facilities” under Section 210 of the Public Utilities Regulatory Policies Act of 1978, shall be on existing dams, diversions, and canals with a sufficient drop so that power may be efficiently generated without significant environmental effects. (e) For hydroelectric power generating facilities, the applicant shall demonstrate that project revenues will exceed project costs, including the cost of mitigation measures over the life of the project. (f) Subdivisions (d) and (e) do not apply to projects with a nameplate capacity of less than 100 kilowatts.

Cal. Water Code - WAT § 107. Section 107.

The declaration of the policy of the State in this chapter is not exclusive, and all other or further declarations of policy in this code shall be given their full force and effect.

Cal. Water Code - WAT § 108. Section 108.

It is hereby declared to be the established policy of this State that in the development and completion of any general or co-ordinated plan prepared and published by the Department of Water Resources or any predecessor thereof or successor thereto, all uses, including needs of the area in which the water originates, of water shall be given consideration. Whenever the Legislature authorizes the construction or acquisition by the State of any project which will develop water for use outside the watershed in which it originates, the Legislature shall at the same time consider the authorization and the construction or acquisition of such other works as may be necessary to develop water to satisfy such of the reasonable ultimate requirements of such watershed as may be needed at the time the export project is authorized or as will be needed within a reasonable time thereafter. The authorization with respect to such additional works may provide for state acquisition or construction, in whole or in part, of any such additional works, or financial assistance to other entities in connection with the acquisition or construction of such works, or a combination thereof.

Cal. Water Code - WAT § 108.5. Section 108.5.

(a) It is hereby declared to be the established policy of the state that source watersheds are recognized and defined as integral components of California’s water infrastructure. (b) (1) As climate change advances, source watersheds that provide the majority of the state’s drinking and irrigated agricultural water are of particular importance to maintaining the reliability, quantity, timing, and quality of California’s environmental, drinking, and agricultural water supply. (2) Recognizing the critical role of source watersheds in enhancing water supply reliability, the maintenance and repair of source watersheds is eligible for the same forms of financing as other water collection and treatment infrastructure. (3) Nothing in this section is intended to constrain financing for source watersheds supplying local, state, or federal water systems. (4) Nothing in this section is intended to supersede federal eligibility requirements or alter any of the following: (A) Funding criteria or guidelines established for a bond or other measure enacted by the voters. (B) Funding programs related to pollution control, cleanup, or abatement. (C) Funding programs for addressing public health emergencies. (c) Eligible maintenance and repair activities pursuant to this section are limited to the following forest ecosystem restoration and conservation activities: (1) Upland vegetation management to restore the watershed’s productivity and resiliency. (2) Wet and dry meadow restoration. (3) Road removal and repair. (4) Stream channel restoration. (5) Conservation of private forests to preserve watershed integrity through permanent prevention of land use conversion and improved land management, achieved through, and secured with, conservation easements. (6) Other projects with a demonstrated likelihood of increasing conditions for water and snow attraction, retention, and release under changing climate conditions.

Cal. Water Code - WAT § 109. Section 109.

(a) The Legislature hereby finds and declares that the growing water needs of the state require the use of water in an efficient manner and that the efficient use of water requires certainty in the definition of property rights to the use of water and transferability of such rights. It is hereby declared to be the established policy of this state to facilitate the voluntary transfer of water and water rights where consistent with the public welfare of the place of export and the place of import. (b) The Legislature hereby directs the Department of Water Resources, the State Water Resources Control Board, and all other appropriate state agencies to encourage voluntary transfers of water and water rights, including, but not limited to, providing technical assistance to persons to identify and implement water conservation measures which will make additional water available for transfer.

Cal. Water Code - WAT § 110. Section 110.

(a) The Legislature hereby finds and declares all of the following: (1) The use of potable water to irrigate nonfunctional turf is wasteful and incompatible with state policy relating to climate change, water conservation, and reduced reliance on the Sacramento-San Joaquin Delta ecosystem. (2) The Governor reported in August 2022 that climate change will bring significant enduring reductions in California’s water supply and that the state must take steps to respond to this reality. (3) The State of Nevada enacted AB 356 in 2021 to prohibit the use of Colorado River water to irrigate nonfunctional turf on all properties except single-family residences by January 1, 2027. (b) It is the intent of the Legislature that the irrigation of grasses for agricultural production shall not be limited by requirements to eliminate the use of potable water to irrigate nonfunctional turf. (c) The Legislature hereby directs all appropriate state agencies to encourage and support the elimination of irrigation of nonfunctional turf with potable water.

Cal. Water Code - WAT § 112. Section 112.

(a) The efficiency of a reverse osmosis water treatment device means the percentage of water which passes through the water treatment device that is available for subsequent domestic use and which is not discharged directly from the device to the waste disposal system of the residence where the device is used. (b) Notwithstanding any other provision of law, after January 1, 1991, no reverse osmosis water treatment device shall be sold, installed, or rented, for residential use, including any general domestic purposes such as drinking, cleaning, washing, or sanitation, unless the device is equipped with an automatic waste shutoff device or, through other equipment design specifications, achieves or exceeds equal or greater water savings than would occur with an automatic shutoff device. (c) Effective January 1, 1993, any reverse osmosis water treatment device sold, installed, rented, or under service contract prior to January 1, 1991, for residential use shall be retrofit with an automatic waste shutoff device, or, through other equipment design specifications, achieve or exceed equal or greater water savings than would occur with an automatic shutoff device.

Cal. Water Code - WAT § 113. Section 113.

It is the policy of the state that groundwater resources be managed sustainably for long-term reliability and multiple economic, social, and environmental benefits for current and future beneficial uses. Sustainable groundwater management is best achieved locally through the development, implementation, and updating of plans and programs based on the best available science.

Source: CA Legislative Counsel Bulk DataURL: https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zipFetched: 6/27/2026