California Water Access and Water Rights Overview (19-CA-a)
California has a hybrid surface water law system, containing elements of both riparian and prior appropriation water rights. In times of shortages, riparian rights are superior to appropriative rights, and later appropriators are subordinate to prior appropriators.
California law provides for different treatment of surface water and groundwater. However, groundwater that is closely related to or behaves like surface water (“water flowing within a known and defined channel”) is classified as “subterranean streams” and subject to the same rules and regulations as surface water. The SWRCB regulates these subterranean streams. There is four-part test for determining whether groundwater falls within the SWRCB regulation authority. “For groundwater to be classified as subterranean stream flowing through a known and definite channel, the following physical conditions must exist:
- A subsurface channel must be present;
- The channel must have a relatively impermeable bed and banks;
- The course of the channel must be known or capable of being determined by reasonable inference; and
- Groundwater must be flowing in the channel.”
All other sub-surface water is defined as “percolating groundwater” and is not subject to regulation by the SWRCB. Most groundwater in California is percolating groundwater. The SWRCB has no jurisdiction over the extraction and use of percolating groundwater supplies. Rather, rights to percolating groundwater are determined by the court system and subject, in most cases, to local groundwater management. Groundwater supplies in California are generally managed by some form of local entity, such as a water master within a defined water district. Local groundwater management agencies or voluntary groundwater management plans must be considered in applicable project locations.
Many groundwater basins in California, particularly those with the highest demand in relation to supply, are managed pursuant to a judgment entered by a court in a groundwater adjudication. The majority of adjudicated basins are located in Southern California where groundwater shortages and overdraft conditions have historically been greatest. However, newer adjudications have recently been completed to the north on the state’s central coast, e.g., Seaside, Los Osos and Santa Maria.The developer should secure any necessary water rights early on in the planning and development process, as the developer may need to provide evidence of a water right in order to proceed with or complete many stages of the regulatory process.
Water Access and Water Rights Overview Process
19-CA-a.1 – Calculate Project Need
The developer will need to contact a water engineer/consultant to calculate the amount of water the project (e.g. power generation, reservoir fill, pumped storage, construction, dust suppression, etc.) requires.
19-CA-a.2 – Locate Source of Water Supply
The developer, with the assistance of a water engineer/consultant, must locate an appropriate source of water supply based on the project’s water requirement.
19-CA-a.3 – Will the Project Use Surface Water?
Depending on the type of hydropower facility and the amount of water needed, the developer may use surface water to meet all or part of the project’s water requirement.
19-CA-a.4 to 19-CA-a.5 – Will the Project Alter, Change, or Deposit Materials Into a Streambed or Lakebed?
Prior to commencing with a hydropower project, the developer must contact the California Department of Fish & Wildlife (CDFW) to initiate the Streambed/Lakebed Alteration Agreement process if the project may:
- Substantially divert or obstruct the natural flow of any river, stream or lake;
- Substantially change or use any material from the bed, channel, or bank of, any river, stream, or lake; or
- Deposit or dispose of debris, waste, or other material containing crumbled, flaked, or ground pavement where it may pass into any river, stream or lake.
19-CA-a.6 – Will the Project Store Water?
If a hydropower project will divert water for storage (such as for a dam or pumped storage hydropower facility), the developer must acquire an appropriative water right. “Storage” of water means the collection of water in a tank or reservoir at times of higher stream flow for use at times of diminished flow. For licensing purposes, all initial and refill collections of water held in a tank or reservoir for more than 30 days is considered water diverted for storage. Cal. Code Regs. tit. 23 § 658.
19-CA-a.7 to 19-CA-a.8 – Will the Project’s Water Need Be Satisfied By a Riparian Water Right?
Where a hydropower project is located on a parcel of land abutting a surface water source, and the project will not divert water for storage, the developer is entitled to use a share of the surface water flowing past its property. The developer’s riparian right may be sufficient to satisfy the project’s entire water need. In most cases, riparian rights take priority over appropriative rights, but are still subject to certain fundamental principles. Riparian rights are subject to the public trust and may not harm the riparian rights, and in some cases, the appropriative rights, of others. Half Moon Bay Land Co. v. Cowell, 173 Cal. 543 (Cal. 1916).
Although developers need not take action to vest a riparian right, a developer diverting water under a riparian claim should establish a record of water use by filing a Statement of Water Use and Diversion with the SWRCB.
If the developer has a riparian right sufficient to satisfy the entire project’s water need, no permit is needed and the developer may continue with the project. However, where the project requires more water than available in the particular riparian context and/or future uncertainty exists regarding the scope of the riparian right, the developer should consider other avenues available for acquiring water for the project.
19-CA-a.9 to 19-CA-a.12 – Does the Developer Seek to Add Hydropower to an Existing Permit or License?
A developer with an existing water permit or license may petition the SWRCB to add hydropower to the permit or license, as a beneficial use, if the use of water for power will not result in changes to the streamflow regime. However, the developer must apply for, purchase or transfer a water right if:
- The use of water for power will change the stream flow regime; or
- Additional water will be needed to meet the project’s water requirement.
The criteria SWRCB considers in determining whether the use of water for power would change the streamflow regime includes, but is not limited to:
- Will the rate and volume of flow be changed?
- Will the water temperature be changed?
- Will there be changes in the concentration of dissolved oxygen or turbidity?
- Will there be changes in the timing of water releases from any existing water diversion or storage facility?
- Will there be a change in the point of discharge or will any additional section of watercourse be bypassed?
19-CA-a.13 to 19-CA-a.14 – Is the Source of Water Supply Fully Appropriated?
If the source of water supply the developer seeks to acquire for the project is not fully appropriated, the developer would need to file an Application to Appropriate Water with the SWRCB. Appropriated water is also subject to the public trust doctrine to protect instream flows. The procedure for appropriating surface water in California is separate and unique from the equivalent process for groundwater sources. For an outline of the process to appropriate surface water, see
If the source of water supply sought by the developer is fully appropriated, the developer will need to consider the remaining avenues available for water acquisition, described below.
19-CA-a.15 – Locate Appropriated Water Right Available for Sale or Transfer?
At this point in the process the developer may seek to purchase or transfer a water right from a third party. To procure an established water right, the developer will need to negotiate the purchase or transfer of an existing water right with the current owner. Depending on the type of right acquired, different processes apply.
19-CA-a.16 to 19-CA-a.17 – Was the Appropriated Water Right Perfected Prior to 1914?
Where a developer acquires an appropriative water right perfected prior to December 19, 1914, the developer does not have to submit a petition with the SWRCB. The SWRCB’s authority to regulate the transfer of appropriative surface water rights and subterranean streams derives from the California Water Commission Act, now incorporated in the California Water Code. Appropriative water rights perfected prior to enactment of the California Water Commission Act are not subject to regulation by the SWRCB.
Nevertheless, any developer diverting water under a prior appropriation claim that vested prior to 1914 should seek to establish a record of water use by filing a Statement of Water Use and Diversion with the SWRCB, if a statement of use has not already been filed. Establishing a record of water use is helpful in validating pre-1914 appropriative rights in cases of future challenge.
19-CA-a.18 to 19-CA-a.19 – Does the Developer Seek to Purchase a Water Right?
If seeking to purchase a water right, the developer will need to provide the SWRCB notice of the change in ownership so that the change may be recorded. For a full description of the process, see
19-CA-a.20 – Initiate Process to Transfer Appropriated Water Right
As an alternative to purchasing a water right, the developer may seek to transfer an existing appropriated water right from a third-party to meet the project’s water requirement. The process for initiating a long-term transfer of a post-1914 appropriative water right is outlined in
19-CA-a.21 to 19-CA-a.24 – Will the Supply Require a Change in the Purpose, Location of Use or Point of Diversion?
Subsequent to a change in ownership, the developer may need to change the purpose or location of use or point of diversion of the water right. Practically, this change could be effected by the original owner of the water right, prior to the developer’s purchase. However, the developer may choose to purchase the right and then go through the change process. In such cases, the developer must submit a Petition to Change an Existing Water Right to the SWRCB. For a full description of the process see
Where the newly-owned water right is permitted for the purpose and location of use and point of diversion that the project requires, there are no additional requirements and the developer may continue with the project.
19-CA-a.25 – Initiate Process to Transfer Appropriated Water Right
The developer may seek to transfer an existing appropriated water right from a third-party to meet the project’s water requirement. The process for initiating a long-term transfer of a post-1914 appropriative water right is outlined in
19-CA-a.26 to 19-CA-a.27 – Will project’s water requirement be met by use of municipal wastewater?
Unlike conventional on-stream pumped storage systems, modular off-stream pumped storage (MPS) systems use artificially created water systems (instead of natural waterways or watersheds) and may be sited on areas not abutting a surface water source. These MPS systems may rely on municipal wastewater or groundwater to meet the project’s water need. If relying on municipal wastewater to meet the project’s water requirement, the developer will negotiate a private purchase with a provider of recycled, non-potable water.
19-CA-a.28 to 19-CA-a.29 – Seek Appropriation of Groundwater
In California, percolating groundwater is treated separately from surface water. The SWRCB does not retain authority over percolating groundwater. Instead, overlying landowners have an equal and correlative right to the percolating groundwater beneath their land. Appropriation of groundwater generally may not create overdraft and is subject to future needs of overlying landowners. Certain groundwater basins in California have been fully adjudicated by the courts and extractions (in excess of 25 acre-feet per annum) of groundwater within the counties of Riverside, San Bernardino, Los Angeles, and Ventura requires a notice filed with the SWRCB. Nevertheless, developers may be able to acquire groundwater to fulfill all or part of their project needs.
For a complete description of the Groundwater Considerations, see
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