Everyone who diverts water under a riparian water right must report their water use regularly by filing a Statement of Diversion and Use. These actually come in two forms:
• An Initial Statement of Diversion and Use is what you file if you are reporting riparian use from a diversion for the first time.
• A Supplemental Statement of Diversion and Use is what you file in subsequent years for that same diversion.
A Statement of Diversion and Use does not create your riparian water right – which already exists by virtue of your ownership of property abutting a stream. Instead, it serves several important purposes:
• Puts the state and other users on notice of your riparian rights
• Helps the Water Board determine how much (if any) water is left to give out to new appropriative rights
• Ensures the Water Board will notify you of any applications for new water rights in the same stream system
• Prevents you from being fined under Water Code Section 5107
Note that you do not have to fill out a Statement of Diversion and Use for any water you use under a Small Domestic Use Registration. You report that use separately as required by your registration document.