How deep is the water table in Idaho?
It varies from a median of 17 ft in Washington County to 243.5 ft in Lincoln, measured across 186,880 Idaho well records. Depth to water is not the same as well depth — it is how far below the surface water settles, and it decides what pump you need and what it costs to run.
Median depth to water for every county, why it is not the same as well depth, and what it changes about running cost.
By WellDepthPublished
Depth to water is not well depth
These are two different measurements and mixing them up is the most common confusion in the whole dataset. Total depth is how far the driller drilled. Depth to water — the static water level — is how far below the surface water settles once the well is finished.
A well can be drilled hundreds of feet past the level water rises to. Total depth drives what the hole costs; depth to water drives what pump you need and what it costs to run every month.
| # | County | Median depth to water | Typical range | Records |
|---|---|---|---|---|
| 1 | Washington | 17 ft | 6–80 ft | 2,479 |
| 2 | Shoshone | 18 ft | 6–112 ft | 1,137 |
| 3 | Lemhi | 20 ft | 5–80 ft | 3,013 |
| 4 | Gem | 23 ft | 4–82 ft | 4,341 |
| 5 | Payette | 24 ft | 8–110 ft | 3,723 |
| 6 | Madison | 24 ft | 8–94 ft | 3,776 |
| 7 | Bear Lake | 27.5 ft | 6–175 ft | 1,004 |
| 8 | Valley | 28 ft | 8–102 ft | 7,095 |
| 9 | Camas | 28 ft | 8–100 ft | 898 |
| 10 | Blaine | 29 ft | 6–110 ft | 4,014 |
| 11 | Custer | 30 ft | 8–118 ft | 2,421 |
| 12 | Owyhee | 31 ft | 10–160 ft | 2,727 |
| 13 | Canyon | 40 ft | 8–140 ft | 17,996 |
| 14 | Ada | 40 ft | 8–155 ft | 16,802 |
| 15 | Jefferson | 43 ft | 8–135 ft | 7,809 |
| 16 | Bonner | 45 ft | 10–168 ft | 12,778 |
| 17 | Boundary | 45 ft | 10–180 ft | 1,715 |
| 18 | Bingham | 50 ft | 19–116 ft | 7,935 |
| 19 | Caribou | 50 ft | 9–196 ft | 1,895 |
| 20 | Franklin | 50 ft | 8–216 ft | 1,331 |
| 21 | Boise | 54 ft | 10–162 ft | 2,862 |
| 22 | Butte | 59 ft | 16–191 ft | 1,300 |
| 23 | Bannock | 60 ft | 22–180 ft | 3,971 |
| 24 | Adams | 60 ft | 10–225 ft | 1,733 |
| 25 | Oneida | 65 ft | 18–230 ft | 1,489 |
| 26 | Latah | 70 ft | 12–210 ft | 3,349 |
| 27 | Fremont | 72 ft | 15–198 ft | 4,790 |
| 28 | Benewah | 72 ft | 15–210 ft | 2,314 |
| 29 | Teton | 75 ft | 16–210 ft | 3,680 |
| 30 | Twin Falls | 78 ft | 19–230 ft | 8,564 |
| 31 | Power | 80 ft | 25–259 ft | 1,343 |
| 32 | Cassia | 90 ft | 17–348 ft | 5,303 |
| 33 | Minidoka | 94 ft | 8–264 ft | 4,363 |
| 34 | Idaho | 100 ft | 17–360 ft | 4,328 |
| 35 | Kootenai | 105 ft | 20–360 ft | 9,918 |
| 36 | Nez Perce | 112 ft | 18–500 ft | 1,782 |
| 37 | Lewis | 118.5 ft | 21–436 ft | 548 |
| 38 | Bonneville | 120 ft | 25–220 ft | 5,714 |
| 39 | Clearwater | 120 ft | 22–334 ft | 1,633 |
| 40 | Gooding | 128 ft | 67–195 ft | 3,436 |
| 41 | Clark | 130 ft | 20–356 ft | 430 |
| 42 | Elmore | 145 ft | 15–425 ft | 3,799 |
| 43 | Jerome | 198 ft | 113–340 ft | 4,040 |
| 44 | Lincoln | 243.5 ft | 165–435 ft | 1,302 |
186,880 of 208,243 records report a static water level — the most complete of the three main fields. Readings of exactly zero are excluded as ambiguous.
The range across the state
Washington County has the shallowest median water table in Idaho at 17 ft, from 2,479 records. Lincoln County has the deepest at 243.5 ft.
That is not the same ordering as total depth, which is the point of publishing it separately. A county can have deep wells and a shallow water table, or the reverse, and the two cost you in different ways.
Why a single reading is weaker than it looks
A static water level is recorded once, on the day the well was finished, in whatever year that was. Water tables move seasonally and over longer cycles, so a figure from a well drilled in August 1994 describes that day.
Taken across hundreds of records in a county the pattern is meaningful. Taken from one record it is a snapshot.
What a county figure cannot tell you
A county median describes the wells people drilled and reported, not the ground under one parcel. Groundwater varies over short distances, and these records sit on other people’s property.
Use a county figure to know which questions to ask and roughly what to budget. Use the records near a specific point to know how much that budget could move. Neither is a substitute for a written quote from a licensed Idaho driller.
Sources
Check a specific location
See the well records the state holds near any point in Idaho — free, no account.
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