Soil Drainage Rankings by State

Drainage class is one of the most important properties in any soil survey. It determines how quickly water moves through the soil profile, which affects everything from foundation stability to septic system viability to what you can grow in your garden.

The USDA classifies every mapped soil into one of seven drainage classes, from "excessively drained" (water disappears almost immediately) to "very poorly drained" (water sits at or near the surface for most of the year). We ranked every state by the percentage of surveyed land classified as "well drained" — the sweet spot where water moves through at a healthy rate without waterlogging or running off too fast.

States with high well-drained percentages tend to have sandy, loamy, or well-structured soils — typically easier and cheaper to build on and garden in. States with low percentages have more clay, wetlands, or high water tables, meaning more properties will need engineered solutions for construction and septic.

#	State	Well Drained	Poorly Drained
1	American Samoa	96%	2%
2	Mexico	95%	0%
3	Virgin Islands	95%	4%
4	New Mexico	92%	0%
5	Guam	92%	6%
6	Wyoming	92%	2%
7	Montana	91%	2%
8	Northern Mariana Islands	89%	1%
9	Idaho	87%	2%
10	West Virginia	87%	1%
11	Nevada	86%	5%
12	Oregon	83%	5%
13	Colorado	81%	3%
14	Puerto Rico	80%	10%
15	South Dakota	79%	8%
16	Arizona	78%	0%
17	Washington	77%	4%
18	District of Columbia	77%	1%
19	Kentucky	77%	7%
20	Utah	77%	9%
21	Palau	76%	18%
22	Hawaii	74%	2%
23	Texas	74%	6%
24	Oklahoma	71%	10%
25	Virginia	71%	11%
26	Kansas	69%	8%
27	Federated States of Micronesia	68%	22%
28	United States	66%	19%
29	Alabama	63%	16%
30	Tennessee	62%	8%
31	Connecticut	60%	14%
32	Georgia	60%	29%
33	California	59%	5%
34	New Hampshire	55%	14%
35	North Carolina	55%	29%
36	Pennsylvania	54%	16%
37	Maryland	53%	23%
38	Nebraska	53%	8%
39	North Dakota	51%	22%
40	South Carolina	46%	33%
41	Vermont	45%	20%
42	Rhode Island	44%	19%
43	Arkansas	43%	35%
44	Massachusetts	42%	18%
45	Alaska	42%	52%
46	New Jersey	41%	28%
47	New York	40%	27%
48	Wisconsin	38%	32%
49	Mississippi	38%	34%
50	Iowa	36%	43%
51	Delaware	36%	38%
52	Ohio	35%	43%
53	Indiana	30%	46%
54	Missouri	29%	30%
55	Illinois	27%	56%
56	Michigan	26%	44%
57	Minnesota	24%	54%
58	Maine	19%	42%
59	Louisiana	18%	63%
60	Florida	7%	74%
61	Marshall Islands	0%	0%

What Drainage Class Means in Practice

Well drained soil removes water readily but not rapidly. The soil is not wet for a significant part of the growing season. This is the ideal condition for most construction, septic systems, and gardens.

Poorly drained soil removes water so slowly that the soil stays wet for extended periods. This creates challenges for foundations (hydrostatic pressure, frost heave), septic systems (effluent can't percolate), and most garden plants (root rot). Properties in poorly-drained areas typically require engineered drainage, alternative septic systems, or raised-bed gardening.