Idaho passed SB1083A, revising how domestic wells and water exemptions work. This became effective July 1st, 2025. Our surrounding area relies heavily on domestic wells, especially in subdivisions. It is important to clarify when you, a homeowner, needs a water right versus when you qualify for an exemption.

What Changed in Idaho Water Law?

Domestic exemption still exists, but the definitions and limits have shifted. There are two major thresholds that determine whether a use can be considered “domestic”:

1. Up to 13,000 gallons per day for homes/campgrounds/livestock and up to ½ acre irrigation

2. OR up to 2.8 acre-feet per year for any purpose if not covered above

Water in subdivisions and groundwater-regulated areas is treated differently than water on standalone parcels.

How These Rules Apply in Teton Valley and Surrounding Areas

If you live in Tetonia, Driggs, or Victor, much of Teton Valley is not in a regulated groundwater area. Therefore, individual lots (not in a subdivision) can generally pump up to 13,000 gpd + ½ acre irrigation without a permit. For subdivisions outside regulated areas, you can have irrigation from domestic wells if the subdivision does not exceed domestic limits and the well is not supplying multiple homes beyond in-home allowances.

If you live in Ashton or Fremont County, areas surrounding Ashton tie into the Eastern Snake Plain Aquifer (ESPA), which is a GWMA in some zones. Therefore subdivisions in regulated zones are in-home use only unless you hold a water right. Single-parcel properties outside subdivisions may still irrigate up to ½ acre under the domestic exemption. See Decision Tables and Trees for more.

What This Means for Homebuyers and Sellers

• Buyers should understand:

• Whether irrigation is legally allowed

• Whether the well currently serves multiple parcels

• Whether the parcel sits in a regulated groundwater area

• Sellers should disclose:

• Whether they have a recorded water right

• Whether irrigation is permitted or not

• Any shared-well agreements

Quick Decision Checklist

• Are you in a regulated area?

• If yes, outdoor irrigation likely needs a permit.

• Is it a shared well?

• Exempt is in-home only

• How much water will you use?

• Stay under 13,000 gpd (home + ½ acre) or 2.8 AF/year

• When does use begin?

• After July 1st, 2025 uses follow new rules.

Scenarios:

“I live in a subdivision and want to water my lawn.”

• In a regulated groundwater area?

• You can only use water for in-home use unless you have a water right.

• Not in regulated area?

• You may irrigate up to ½ acre if the total combined use stays under limits.

“I want to drill a domestic well on my acreage outside of town.”

• Usually exempt as long as you stay under 13,000 gpd and irrigate ½ acre or less.

“Can I share a well with my neighbor?”

• Yes, with restrictions:

1. Combined use must stay under 13,000 gpd and ½ acre irrigation.

2. Additional exempt uses after the first on the same well may be limited to in-home only.

“My subdivision uses a community well. Can I add irrigation?”

• Depends on:

1. Whether you're in a regulated area

2. Whether the HOA has a recorded water right

3. Whether your added use would exceed exemption thresholds

Key Terms

1. Domestic Use – Defined categories like homes, campgrounds, livestock, and irrigation of up to ½ acre

2. 2.8 Acre-Feet Rule – A major expansion: A use for “any purpose” may qualify if less than or equal to 2.8 acre-feet per year.

3. Subdivision Rules – Subdivisions in groundwater regulated areas have stricter requirements. This is more specifically in areas bordering Teton Valley and surrounding area. Some uses are limited to in-home only.

4. Shared Wells – Homeowners can now share a single exempt domestic well across multiple parcels, but irrigation and volume limits are cumulative.

5. Regulated Areas – Moratorium zones, Ground Water Management Areas, and Critical Ground Water Areas change what is exempt. Flow charts lay this out clearly. (See decision table and flow charts)

How Teton Real Estate Group Can Help

• Title review and county lookup for regulated-area status

• Helping our clients determine if irrigation is permitted

• Clarifying when buyers may need to secure a water right

• Connecting homeowners with local water-right consultants and IDWR resources

The 2025 law changes mean irrigation, shared wells, and subdivision water use rules are no longer one-size-fits-all. For buyers and homeowners in Tetonia, Driggs, Victor, and surrounding areas, understanding these new rules can prevent surprises and protect your investment.

See decision tables and tree

Read IDWR’s Memo

See IDWR Map

Visit idwr.idaho.gov and contact them at [email protected].