Idaho Soil Drainage Rankings

Idaho

How well does the soil drain across Idaho? We ranked every USDA survey area by the percentage of land classified as "well drained." Areas at the top of the list have soils where water moves through at a healthy rate — favorable for building, septic, and gardening. Areas at the bottom have more waterlogged or slowly-draining soils that may require engineered solutions.

The best-drained survey area is Salmon National Forest, Idaho at 99% well-drained soils. The most drainage-challenged is Valley Area, Idaho, Parts of Adams and Valley Counties at 25%.

#	Survey Area	Well Drained	Poorly Drained	Dominant Class
1	Salmon National Forest, Idaho	99%	0%	Well drained
2	Craters of the Moon National Monument and Preserve, Idaho	99%	0%	Well drained
3	City of Rocks National Reserve, Idaho	99%	0%	Well drained
4	Challis National Forest, Eastern Part, Idaho	98%	1%	Well drained
5	Caribou National Forest, Idaho and Wyoming	98%	0%	Well drained
6	Jerome County and Part of Twin Falls County, Idaho	98%	0%	Well drained
7	Bonneville County Area, Idaho	97%	1%	Well drained
8	Butte County Area, Idaho, Parts of Butte and Bingham Counties	97%	2%	Well drained
9	Seven Devils Area, Idaho	97%	0%	Well drained
10	Cassia County, Idaho, Eastern Part	96%	1%	Well drained
11	Power County Area, Idaho	96%	0%	Well drained
12	Bannock County Area, Idaho, Parts of Bannock and Power Counties	95%	2%	Well drained
13	Wood River Area, Idaho, Gooding County and Parts of Blaine, Lincoln, and Minidoka Counties	95%	0%	Well drained
14	Idaho National Engineering Laboratory, Idaho	95%	3%	Well drained
15	Owyhee County Area, Idaho	95%	1%	Well drained
16	Adams-Washington Area, Parts of Adams and Washington Counties, Idaho	95%	3%	Well drained
17	Oneida County Area, Idaho	93%	2%	Well drained
18	Targhee National Forest, Idaho and Wyoming	93%	1%	Well drained
19	Nez Perce National Forest, Idaho	92%	0%	Well drained
20	Blaine County Area, Idaho	92%	4%	Well drained
21	Elmore County Area, Idaho, Parts of Elmore and Owyhee Counties	92%	1%	Well drained
22	Caribou County Area, Idaho	91%	7%	Well drained
23	Clark County Area, Idaho, Parts of Clark and Butte Counties	91%	3%	Well drained
24	Gem County Area, Idaho	90%	9%	Well drained
25	Duck Valley Indian Reservation, Idaho and Nevada	89%	7%	Well drained
26	South Idaho Forests, Idaho	88%	0%	Well drained
27	Payette County, Idaho	88%	9%	Well drained
28	Ada County, Idaho	88%	3%	Well drained
29	Bonner County Area, Idaho, Parts of Bonner and Boundary Counties	87%	11%	Well drained
30	Clearwater Area, Idaho	87%	2%	Well drained
31	Idaho Panhandle National Forest, Idaho-Washington-Montana	86%	0%	Well drained
32	Bingham Area, Idaho	85%	9%	Well drained
33	Teton Area, Idaho and Wyoming	84%	15%	Well drained
34	Challis National Forest, Western Part, Idaho	84%	2%	Well drained
35	Fort Hall Area, Idaho, Parts of Bannock, Bingham, Caribou, and Power Counties	84%	2%	Well drained
36	Minidoka Area, Idaho, Parts of Minidoka, Blaine, and Lincoln Counties	83%	10%	Well drained
37	Clearwater National Forest, Idaho	83%	0%	Well drained
38	Cassia County, Idaho, West Part	81%	6%	Well drained
39	Canyon Area, Idaho	79%	15%	Well drained
40	Lewis and Nez Perce Counties, Idaho	78%	2%	Well drained
41	Madison County Area, Idaho	77%	12%	Well drained
42	Custer-Lemhi Area, Idaho, Parts of Blaine, Custer, and Lemhi Counties	77%	5%	Well drained
43	St. Joe Area, Idaho, Parts of Benewah and Shoshone Counties	77%	4%	Well drained
44	Fremont County, Idaho, Western Part	77%	6%	Well drained
45	Camas County Area, Idaho	76%	13%	Well drained
46	Idaho County Area, Idaho, Western Part	75%	1%	Well drained
47	Kootenai County Area, Idaho	75%	4%	Well drained
48	Franklin County Area, Idaho	74%	6%	Well drained
49	Jefferson County, Idaho	74%	4%	Well drained
50	Bear Lake County Area, Idaho	73%	22%	Well drained
51	Kooskia Area, Idaho County, Idaho	73%	0%	Well drained
52	Boundary County Area, Idaho	73%	16%	Well drained
53	Middle Fork Payette River Area, Idaho, Parts of Valley and Boise Counties	65%	0%	Well drained
54	Latah County, Idaho	57%	8%	Well drained
55	Benewah County Area, Idaho, Western Part	56%	7%	Well drained
56	Boise County Area, Idaho, Western Part	26%	0%	Somewhat excessively drained
57	Valley Area, Idaho, Parts of Adams and Valley Counties	25%	15%	Somewhat excessively drained