Ask ten Napa growers about water rights and you’ll get twelve different answers — most of them half right and all of them passionate. Between the alphabet soup of riparian, appropriative, and groundwater rules, it’s no wonder the topic makes folks reach for another pour. But understanding who’s got the right to use what water isn’t just a legal headache it’s the backbone of your vineyard’s value and survival.

1. There’s no “one-size-fits-all” right to water

In Napa, who gets to use what water depends on how and when that right was established. There are two main buckets:

• Riparian rights If your property borders a creek, stream, or river, you’ve got the right to use that water so long as it’s not harming your downstream neighbor. You can’t store it long-term or haul it elsewhere; it’s a “use it here and now” deal.

• Appropriative rights If you’re pulling water from a surface source (like a creek) and you filed or inherited a state permit to do so, that’s an appropriative right. These are prioritized by date first come, first served which means if things get dry, older rights holders get theirs first.

2. Groundwater’s a whole other animal

Napa’s groundwater isn’t as regulated (yet) as surface water, but the county’s been tightening up. Most vineyard folks pull from wells, and under the Groundwater Sustainability Plan (GSP) for the Napa Valley Subbasin, the county’s keeping tabs on who’s pumping how much. They’re watching levels, recharge rates, and usage to keep things sustainable because nobody wants a dry well or a state takeover.

3. Storage and ponds

If you’ve got a reservoir or off-stream pond, odds are you need a water storage permit from the State Water Resources Control Board. A lot of those “old family ponds” are grandfathered in, but if you’re building new or expanding, expect to deal with paperwork and fish and wildlife folks will want to make sure you’re not messing with seasonal flow or steelhead habitat.

4. Frost protection and vineyard use

The frost protection wars of the early 2010s taught everyone that pulling surface water all at once can crash a stream. Now, most frost protection setups rely on stored water or wells, with monitoring programs in sensitive areas like the Napa River watershed and Carneros.

5. The practical side

If you’re buying or selling vineyard land, water rights can make or break the deal. A parcel with a permitted well or legal storage pond is worth more and if it’s got a riparian or appropriative right on file, that’s gold. But don’t assume just because there’s a pump, it’s legal. Always verify with the State Water Board’s eWRIMS database or the county resource maps.

6. What’s ahead

Between SGMA (the groundwater act), climate variability, and environmental scrutiny, the days of “drill and go” are over. Expect more monitoring, more reporting, and more neighbors keeping an eye on how you manage your water.

If you’re eyeing a property, planning a pond, or just wondering whether your “old family well” is really in the clear, don’t leave it to rumor. Let’s talk about your vineyard’s water position before the next dry season makes it urgent. Reach out and I’ll help you read the fine print before it costs you your crop.