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California Soil Drainage Rankings

California

How well does the soil drain across California? 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 Central Sierra Foothills Area, California, Parts of Calaveras and Tuolumne Counties at 98% well-drained soils. The most drainage-challenged is Colorado Desert Area, California at 6%.

stays wet (poorly drained)in between, or not ratedwell drained
#Survey AreaLand by drainageWell DrainedPoorly DrainedMost common class
1 Central Sierra Foothills Area, California, Parts of Calaveras and Tuolumne Counties 98% 0% Well drained
2 Mariposa County Area, California 98% 0% Well drained
3 Redwood National and State Parks, California 96% 1% Well drained
4 El Dorado Area, California 94% 0% Well drained
5 Los Angeles County, California, West San Fernando Valley Area 93% 0% Well drained
6 Humboldt and Del Norte Area, California 92% 2% Well drained
7 Nevada County Area, California 91% 0% Well drained
8 San Luis Obispo County, California, Carrizo Plain Area 90% 1% Well drained
9 Lassen Volcanic National Park, California 90% 3% Well drained
10 Six Rivers National Forest Area, California 89% 1% Well drained
11 Modoc National Forest Area, California 89% 0% Well drained
12 Eastern Santa Clara Area, California 88% 3% Well drained
13 Mendocino County, Western Part, California 87% 4% Well drained
14 Kern County, California, Northwestern Part 87% 4% Well drained
15 San Luis Obispo County, California, Paso Robles Area 87% 0% Well drained
16 Los Padres National Forest Area, California 86% 0% Well drained
17 Surprise Valley-Home Camp Area, California and Nevada 86% 6% Well drained
18 Placer County, California, Western Part 85% 4% Well drained
19 Stanislaus County, California, Western Part 85% 4% Well drained
20 Inyo National Forest, Eastern Part, California and Nevada 85% 0% Well drained
21 San Mateo County, Eastern Part, and San Francisco County, California 85% 9% Well drained
22 Tehama County, California 85% 0% Well drained
23 San Benito County, California 85% 4% Well drained
24 Klamath National Forest Area, Parts of Siskiyou County, California, and Jackson County, Oregon 84% 0% Well drained
25 Humboldt County, South Part, California 83% 1% Well drained
26 Lassen National Forest, California, Parts of Lassen, Plumas, Butte, Shasta, and Siskiyou Counties 82% 1% Well drained
27 Humboldt County, Central Part, California 82% 9% Well drained
28 Trinity County, California, Weaverville Area 81% 0% Well drained
29 Modoc County, California, Alturas Area 81% 13% Well drained
30 Tulare County, California, Central Part 81% 0% Well drained
31 Coleville-Bridgeport Area, Parts of Alpine and Mono Counties, California 81% 11% Well drained
32 Alameda Area, California 80% 4% Well drained
33 Shasta-Trinity National Forest Area, Parts of Humboldt, Siskiyou, Shasta, Tehama, and Trinity Counties, California 80% 0% Well drained
34 Santa Clara Area, California, Western Part 80% 8% Well drained
35 Amador Area, California 79% 0% Well drained
36 San Mateo Area, California 79% 2% Well drained
37 Antelope Valley Area, California 78% 0% Well drained
38 Kern County, California, Southwest Part 78% 9% Well drained
39 Santa Monica Mountains National Recreation Area 77% 1% Well drained
40 Stanislaus County, California, Northern Part 77% 1% Well drained
41 Susanville Area, Parts of Lassen and Plumas Counties, California 75% 5% Well drained
42 Mendocino County, Eastern Part and Southwestern Part of Trinity County, California 75% 2% Well drained
43 Ventura Area, California 75% 12% Well drained
44 Los Angeles County, California, Southeastern Part 75% 9% Well drained
45 High Sierra Area, California 74% 0% Well drained
46 Siskiyou County, California, Central Part 74% 6% Well drained
47 Shasta County Area, California 74% 0% Well drained
48 Channel Islands Area, California, Parts of Santa Barbara and Los Angeles Counties 74% 0% Well drained
49 Kern County, Northeastern Part, and Southeastern Part of Tulare County, California 72% 1% Well drained
50 Plumas National Forest Area, California 72% 1% Well drained
51 Rogue River National Forest Area, California 71% 0% Well drained
52 Intermountain Area, Parts of Lassen, Modoc, Shasta, and Siskiyou Counties, California 71% 9% Well drained
53 Monterey County, California 71% 1% Well drained
54 Tahoe National Forest Area, California 70% 2% Well drained
55 Mendocino National Forest Area, California 69% 0% Well drained
56 Yuba County, California 68% 4% Well drained
57 Fish Lake and Deep Springs Valleys Area, California 67% 1% Well drained
58 Sonoma County, California 66% 8% Well drained
59 Kern County, California, Southeastern Part 66% 0% Well drained
60 Lake County, California 65% 2% Well drained
61 Inyo County Area, California 65% 0% Well drained
62 Santa Barbara County, California, South Coastal Part 65% 2% Well drained
63 National Training Center, Fort Irwin, California 64% 0% Well drained
64 Glenn County, California 64% 16% Well drained
65 Eastern Fresno Area, California 64% 16% Well drained
66 Napa County, California 63% 10% Well drained
67 Toiyabe National Forest Area, California 62% 1% Well drained
68 Marin County, California 62% 13% Well drained
69 Fresno County, California, Western Part 62% 18% Well drained
70 Pinnacles National Monument, California 62% 0% Well drained
71 Contra Costa County, California 62% 18% Well drained
72 Stanislaus National Forest, California, Parts 61% 0% Well drained
73 San Luis Obispo County, California, Coastal Part 61% 1% Well drained
74 Madera Area, California 61% 10% Well drained
75 Santa Cruz County, California 60% 7% Well drained
76 Western Riverside Area, California 57% 3% Well drained
77 Eldorado National Forest Area, California, Parts of Alpine, Amador, El Dorado, and Placer Counties 57% 0% Well drained
78 Northern Santa Barbara Area, California 56% 3% Well drained
79 Yolo County, California 56% 32% Well drained
80 Colusa County, California 55% 29% Well drained
81 Butte Valley-Tule Lake Area, California, Parts of Siskiyou and Modoc Counties 54% 29% Well drained
82 Palo Verde Area, California 53% 0% Well drained
83 Merced County, California, Western Part 53% 41% Well drained
84 Sierra National Forest Area Parts of Fresno, California 53% 0% Well drained
85 Eastern Stanislaus Area, California 53% 6% Well drained
86 San Bernardino County, California, Mojave River Area 52% 0% Well drained
87 Orange County and Part of Riverside County, California 51% 12% Well drained
88 San Diego County Area, California 50% 1% Well drained
89 Butte Area, California, Parts of Butte and Plumas Counties 47% 30% Well drained
90 Sequoia National Forest Parts of Fresno, Kern and Tulare Counties, California 45% 0% Well drained
91 Death Valley National Park Area, California and Nevada 45% 0% Somewhat excessively drained
92 Solano County, California 44% 26% Well drained
93 Sierra Valley Area, California, Parts of Sierra, Plumas, and Lassen Counties 44% 32% Well drained
94 Edwards Air Force Base, California, Parts of Kern, Los Angeles, and San Bernardino Counties 42% 0% Well drained
95 Tulare County, Western Part, California 42% 18% Well drained
96 Benton-Owens Valley Area Parts of Inyo and Mono Counties, California 42% 10% Well drained
97 Kings County, California 40% 42% Well drained
98 Sequoia and Kings Canyon National Parks, California 40% 1% Somewhat excessively drained
99 Angeles National Forest Area, California 38% 0% Somewhat excessively drained
100 Merced Area, California 38% 20% Well drained
101 Mojave Desert Area, West Central Part, California 38% 0% Somewhat excessively drained
102 Mojave National Preserve Area, California 36% 0% Somewhat excessively drained
103 Alameda County, California, Western Part 35% 51% Well drained
104 Mojave Desert Area, Northwest Part, California 35% 0% Somewhat excessively drained
105 San Bernardino County Southwestern Part, California 34% 7% Somewhat excessively drained
106 San Joaquin County, California 31% 37% Well drained
107 Anza-Borrego Area, California, Western Part 31% 0% Somewhat excessively drained
108 Marine Corps Air Ground Combat Center at Twentynine Palms, California 31% 0% Somewhat excessively drained
109 Tahoe Basin Area, California and Nevada 29% 6% Somewhat excessively drained
110 San Bernardino National Forest Area, California 29% 0% Somewhat excessively drained
111 Mojave Desert Area, Northeast Part, California 28% 0% Somewhat excessively drained
112 Salton Sea Area, California 26% 48% Poorly drained
113 Joshua Tree National Park, California 26% 0% Somewhat excessively drained
114 Sutter County, California 26% 38% Moderately well drained
115 Sacramento County, California 24% 27% Moderately well drained
116 Riverside County, Coachella Valley Area, California 15% 5% Somewhat excessively drained
117 Inyo National Forest, Western Part, California 14% 2% Somewhat excessively drained
118 Anza-Borrego Area, California, Eastern Part 12% 1% Somewhat excessively drained
119 Imperial County, California, Imperial Valley Area 11% 36% Somewhat poorly drained
120 Mojave Desert Area, California 10% 0% Somewhat excessively drained
121 Yosemite National Park, California 6% 0% Somewhat excessively drained
122 Colorado Desert Area, California 6% 0% Somewhat excessively drained

See also: national drainage rankings | California gardening soil rankings | all California survey areas