Research · updated 2026-08-21 · download the county-level CSV
Idaho Well Depth & Drilling Cost Index
Drilling a private water well in Idaho means paying by the foot — so the two questions every well owner asks are how deep and how much. We computed both for all 44 counties with enough records to be reliable, from 199,803 official IDWR well records.
Statewide, the median well reaches 166 ft, and a complete system — drilling, casing, pump, pressure tank, and hookup — typically runs $12,000–$20,000. But the county spread is large:
Deepest counties to drill in Idaho
| County | Median depth | Typical depth range | Complete system |
|---|---|---|---|
| Kootenai | 380 ft | 247 ft–506 ft | $25,320–$42,200 |
| Elmore | 378 ft | 175 ft–550 ft | $28,140–$46,900 |
| Lincoln | 345 ft | 285 ft–430 ft | $21,840–$36,400 |
| Lewis | 320 ft | 200 ft–500 ft | $21,600–$36,000 |
| Clearwater | 318 ft | 200 ft–450 ft | $19,200–$32,000 |
Most expensive counties to drill in Idaho
| County | Complete system | Drilling & casing only | Median depth |
|---|---|---|---|
| Elmore | $28,140–$46,900 | $11,725–$30,485 | 378 ft |
| Kootenai | $25,320–$42,200 | $10,550–$27,430 | 380 ft |
| Lincoln | $21,840–$36,400 | $9,100–$23,660 | 345 ft |
| Lewis | $21,600–$36,000 | $9,000–$23,400 | 320 ft |
| Nez Perce | $21,600–$36,000 | $9,000–$23,400 | 304 ft |
Download the full county table (CSV)
How to read this
- Depth is measured; cost is modeled. Depths are the median of recorded drilled depths per county. Cost applies published Idaho per-foot drilling rates to that local median depth — a planning estimate, not a quote. Actual bids vary with geology, casing, site access, and water depth.
- Counties below 30 records are excluded so a thin sample can't produce a misleading superlative.
- Records are drilling events from the state database, which include some replacement and abandoned wells; deeper counties reflect real local geology (bedrock, aquifer depth).
Sources & methodology
- Idaho well records: IDWR (refreshed weekly; see our general methodology).
- Percentiles (p25/median/p75) computed per county; cost from published per-foot rate ranges applied to the local median depth.
The county table is free to use with attribution to Idaho Well Data (idahowelldata.com). For a specific county, a custom cut, or the underlying records, email — usually same-day.
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