Anyone who diverts and uses surface water for any reason. This includes you, if you get your water from:
• A creek or river (e.g., via a hose or pipe inserted in the stream)
• A spring, if it flows off your property under natural conditions
• A well, if it diverts water from a surface or underground stream.
Anyone who uses water solely from the following sources:
• An entity such as a municipality, water district, or private water company (provided the entity is properly reporting diversion and use)
• Rainwater collected via rooftop
• Rainwater collected via overland flow before it reaches a stream (be careful, because “stream” includes essentially any gully or ravine, no matter how small)
• A spring that would not flow off their property if allowed to flow naturally (sometimes called a “true spring”)
• A well that does not draw water from any surface or underground stream
If you are filing for the first time for a particular diversion, you will need to fill out an Initial Statement of Water Diversion and Use. If you have filed for this diversion before, you file a Supplemental Statement of Water Diversion and Use.
If you divert water and have never filed an Initial Statement, file one as soon as possible. Each subsequent year, your Supplemental Statement will be due on July 1.
You must fill out a separate Statement for each diversion.
If your SDU registration covers all of your annual water diversion and use, you can simply fill out the reporting form for your registration. Note that it is due by April 1 each year. If your registration is written to cover only your storage, you will need to fill out the registration report (covering the amounts you divert to storage) and a separate Statement (covering your direct diversion under your riparian right). If possible, it’s a good idea when applying for a registration to include your year-round water use).
In most cases, this will be “riparian” – i.e., the water rights that come automatically with the ownership of property abutting a stream.
If you think you can show that you and prior owners have diverted and used continuously, from the same source, without significant lapses, for more than 100 years, then you may be able to claim a pre-1914 appropriative right. This is relatively rare. If you do claim a pre-1914 right, you will want to claim a riparian right as well if you meet the requirements.
If you store water, you need to have a Small Domestic Use Registration, a Small Irrigation Use Registration, or some other kind of appropriative water right. If you do not have any of those, but can claim a riparian right, you should report your non-storage use on the Statement form. You should also apply for a registration or appropriative right authorizing your storage as soon as you possibly can.
The easiest way is to find your property on Google Earth, which shows latitude and longitude (e.g., 44.3851, -121.3457). You can also use CDFW’s BIOS website.
If at all possible, you should. Accurate water data is vastly preferable to estimates. for pump-based diversions, water meters are relatively inexpensive and are great aids to water conservation and planning. For gravity systems, it is usually possible to measure the rate by using a stopwatch (e.g., the one on your smartphone) to see how long it takes to fill a container of known size (e.g., a one-gallon bucket or half-gallon milk container).
If you divert less than 10 acre-feet (3.25 million gallons) of water per year, and measurement is not feasible, you are not strictly required to measure your diversion and use of water (check “diversion is small or minimal in size” in Box 8b). You should estimate the amounts diverted and used. One handy guide is the amount of time it takes you to use up a given size storage tank. Be sure to describe the method you used as best you can in Box 8b.
If you think you may divert more than 10 acre-feet per year, you should see the Water Board’s regulations on measurement requirements.
