7 Water Rights Mistakes Washington Buyers Find Out About Too Late

Washington’s Department of Ecology has mailed water rights adjudication notices to roughly 22,000 people, businesses, and organizations in Whatcom County since 2025.

Many never saw it coming.

Each notice orders the owner to prove in court what water comes with land they already closed on.

These are the water rights mistakes Washington buyers find out about too late.

Note: This is general information, not legal advice. Water rights, well permitting, and irrigation district rules are subject to change, so confirm the specifics of your property with the Washington Department of Ecology’s water resources program.

1. The Exempt Well Cap

A rural property owner in Washington can drill a well without a full water right permit, as long as the use stays inside strict limits.

A permit-exempt well can supply up to 5,000 gallons a day for a single home and another 5,000 gallons a day for an industrial use.

The exemption also covers stock-watering with no daily cap at all, plus a lawn or garden of half an acre or less.

Half an acre isn’t much.

A hobby orchard, a big vegetable garden, or pasture for a couple of horses can go past that limit fast.

The fix is a water right permit, not a bigger pump.

2. Proving Water Before You Build

County building departments across Washington stopped taking a driller’s word on a lot’s water after the state Supreme Court’s 2016 Hirst decision.

The ruling requires a county approving a building permit to confirm that water is legally available before signing off, not take that on faith.

Buyers rarely see it coming.

Buyers of vacant land often find this out only after a building permit stalls, sometimes years after they bought the lot with a house already in mind.

Some counties now require an expensive hydrogeological study before they’ll sign off on a new well-dependent home.

3. Changing an Old Right’s Use

A water right transfers to a new owner automatically the moment the land title changes hands, which surprises buyers who assume they need to file something at closing.

Nobody has to sign anything.

The surprise comes later, when a new owner tries to use that old right differently than the seller did.

Washington requires a formal change application before an owner can use an old right for a new purpose, a new place, or a new point of diversion.

If a buyer skips that step, Ecology can order the new use stopped.

4. The Five-Year Nonuse Rule

Holding the certificate isn’t enough to keep a water right alive forever.

Five years is the line.

Under the Revised Code of Washington (RCW), section 90.14.170, a water right that goes unused for five straight years, without a good legal reason, reverts to the state.

Buyers who inherit an old agricultural right on a parcel they don’t farm can lose it without ever getting a warning letter.

5. A Junior Right’s First Cut

A property’s priority date decides who keeps water when supply runs short, and a buyer who never checks theirs is setting themselves up for an unpleasant surprise.

That ranking comes from prior appropriation, the doctrine the state runs water rights on.

The state serves whoever holds the oldest priority date first, no matter who owns the land today.

Being junior is a risk.

That ranking turned into an open fight in the Yakima Basin in 2026.

Senior irrigation districts sent Washington’s Department of Ecology a letter demanding it curtail junior rights earlier in the season, before their supply took a hit.

A property whose only water right carries a junior date, not an exempt well, can be first in line for a cutoff when a dry summer hits.

6. Irrigation Dues Tied to the Land

Irrigation and reclamation districts across Washington bill by the acre, not by the gallon of water.

A new owner inherits that bill at closing, whether they ever turn on a valve or not.

Ignorance doesn’t get a discount.

The Kittitas Reclamation District, for example, assesses irrigable acreage the Bureau of Reclamation classified back in the 1920s.

A buyer who skips the payoff letter at closing can inherit a lien carrying 12% annual interest.

7. A Well With No Paper Trail

Two or more homes can share a single well under the same exempt-well limits, as long as the combined water use stays under the cap.

No agreement, no answer.

What’s missing on many shared wells is a recorded well-share agreement.

That agreement should cover who maintains the pump, who pays for repairs, and what happens if the property with the well changes hands.

Buyers who never see a written well-share agreement often find that out only after a neighbor sells.

The new owner has no obligation to keep the old, unwritten deal.

The State’s Unfinished Claims

Not every old water claim has been sorted out yet.

The Nooksack basin adjudication in Whatcom County, and a corner of Skagit County, is the clearest example running right now.

A claim to water from before 1917 for surface water, or before 1945 for groundwater, isn’t the same as a confirmed water right.

The court gave more time.

A March 2026 court decision pushed the filing deadline in that case back to June 1, 2027.

Proving a claim by then means filing a court claim form with the Superior Court, not just answering the notice.

Skip it, and there’s no adjudicated certificate, plus the risk of enforcement for using water without one.