Hydrographic Regions and Basins


Washoe County's Hydrographic Regions, Basins and Sub-Basins

(Note: Hydrographic Basins and Sub-Basins listed below may span multiple counties.)

Region [1] Basin [2] Size (sq mi) [3] Size (acres) [4] Hydrographic Basin/Sub-Basin Name County(ies) [5] Nearest City(ies) Des. [6]
[1] NORTHWEST REGION (Hydrographic Region 1):
1 4 494 316,160 Virgin Valley Humboldt, Washoe Denio No
1 6 147 94,080 Guano Valley Washoe, Humboldt Denio, Vya No
1 7 226 144,640 Swan Lake Valley Washoe, Humboldt Denio No
1 8 176 112,640 Massacre Lake Valley Washoe Vya, Cedarville No
1 9 433 277,120 Long Valley Washoe Vya, Cedarville No
1 10 27 17,280 Macy Flat Washoe Vya No
1 11 51 32,640 Coleman Valley Washoe Vya No
1 12 32 20,480 Mosquito Valley Washoe Vya No
1 13 82 52,480 Warner Valley Washoe Vya No
1 14 214 136,960 Surprise Valley Washoe Vya, Cedarville No
1 15 88 56,320 Boulder Valley Washoe Vya, Cedarville No
1 16 533 341,120 Duck Lake Valley Washoe Gerlach No
  Total 3,052 1,953,280 Square miles/acres      
[2] BLACK ROCK DESERT REGION (Hydrographic Region 2):
2 17 12 7,680 Pilgrim Flat Washoe Gerlach No
2 18 31 19,840 Painter Flat Washoe Gerlach No
2 19 39 24,960 Dry Valley Washoe Gerlach, Sutcliffe No
2 20 12 7,680 Sano Valley Washoe Sano, Smoke Creek No
2 21 980 627,200 Smoke Creek Desert Washoe Gerlach, Smoke Creek No
2 22 305 195,200 San Emidio Desert Washoe, Pershing Empire, Gerlach Yes
2 23 9 5,760 Granite Basin Washoe Gerlach No
2 24 315 201,600 Hualapai Flat Washoe, Humboldt, Pershing Gerlach No
2 25 665 425,600 High Rock Lake Valley Washoe, Humboldt Vya, Gerlach No
2 28 2,179 1,394,560 Black Rock Desert Humboldt, Pershing, Washoe Sulfur, Jungo, Summit Lake No
  Total 8,632 5,524,480 Square miles/acres      
[5] WEST CENTRAL REGION (Hydrographic Region 5):
5 76 120 76,800 Fernley Area Lyon, Washoe, Storey, Churchill Fernley, Hazen Yes
  Total 1,656 1,059,840 Square miles/acres      
[6] TRUCKEE RIVER REGION (Hydrographic Region 6):
6 80 371 237,440 Winnemucca Lake Valley Pershing, Washoe, Churchill Nixon, Gerlach No
6 81 672 430,080 Pyramid Lake Valley Washoe, Churchill Nixon, Sutcliffe No
6 82 92 58,880 Dodge Flat Washoe, Churchill Wadsworth No
6 83 285 182,400 Tracy Segment Storey, Washoe, Lyon Sparks, Fernley Yes
6 84 247 158,080 Warm Springs Valley Washoe Sparks Yes
6 85 76 48,640 Spanish Springs Valley Washoe Sparks, Reno Yes
6 86 10 6,400 Sun Valley Washoe Sun Valley, Sparks Yes
6 87 203 129,920 Truckee Meadows Washoe, Storey Reno, Sparks Yes
6 88 39 24,960 Pleasant Valley Washoe Reno, Washoe City Yes
6 89 82 52,480 Washoe Valley Washoe Washoe City Yes
6 90 139 88,960 Lake Tahoe Basin Douglas, Washoe, Carson City Incline Village, Glenbrook, Stateline Yes
6 91 84 53,760 Truckee Canyon Segment Washoe Verdi Yes
  Total 2,300 1,472,000 Square miles/acres      
[7] WESTERN REGION (Hydrographic Region 7):
7 92A 53 33,920 Lemmon Valley/Western Part Washoe Lemmon Valley, Reno Yes
7 92B 40 25,600 Lemmon Valley/Eastern Part Washoe Lemmon Valley, Reno Yes
7 93 18 11,520 Antelope Valley Washoe Lemmon Valley, Sparks Yes
7 94 53 33,920 Bedell Flat Washoe Lemmon Valley Yes
7 95 80 51,200 Dry Valley Washoe D0Yle No
7 96 9 5,760 Newcomb Lake Valley Washoe Doyle No
7 97 193 123,520 Honey Lake Valley Washoe Flanigan, Doyle Yes
7 98 43 27,520 Skedaddle Creek Valley Washoe Smoke Creek, Doyle No
7 99 58 37,120 Red Rock Valley Washoe Bordertown, Lemmon Valley Yes
7 100 30 19,200 Cold Springs Valley Washoe Bordertown, Lemmon Valley Yes
7 100A 25 16,000 Cold Springs Valley/Long Valley Washoe Bordertown Yes
  Total 602 385,280 Square miles/acres      
NEVADA TOTAL-ALL HYDROGRAPHIC REGIONS/BASINS
  Total 110,545 70,748,800 Square miles/acres      
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Hydrographic Regions, Basins, and Sub-Basins Table Notes:

A Region is defined as a geographic area drained by a single major stream or an area consisting of a drainage system comprised of streams and often natural or man-made lakes. Also referred to as Drainage Basin, Watershed, or Hydrographic Region. The U.S. Geological Survey and the Nevada Division of Water Resources, Department of Conservation and Natural Resources, have divided the state into discrete hydrologic units for Water Planning and management purposes. These have been identified as 232 Hydrographic Basins (256 basins and sub-basins, combined) within 14 major Hydrographic Regions.
[1] Nevada Hydrographic Region Number (1-14).
[2] Nevada Hydrographic Basin/Sub-Basin Number (1-232; hydrographic sub-basins designated A, B, C, etc.). There are a total of 256 hydrographic basins and sub-basins.
[3] and [4] Hydrographic basins and sub-basins in square miles and acres, respectively, and include acreage only contained within Nevada.
[5] Counties are listed in order of their share of the hydrographic basin/sub-basin.
[6] Desig = Designated Groundwater Basin. Designated groundwater basins are basins where permitted ground water rights approach or exceed the estimated average annual recharge and the water resources are being depleted or require additional administration. Under such conditions, a state's water officials will so designate a groundwater basin and, in the interest of public welfare, declare preferred uses (e.g., municipal and industrial, domestic, agriculture, etc.). Also referred to as Administered Groundwater Basins. For Nevada, in the interest of public welfare, the Nevada State Engineer, Division of Water Resources, Department of Conservation and Natural Resources, is authorized by statute (Nevada Revised Statute 534.120) and directed to designate a groundwater basin and declare preferred uses within such designated basin. The State Engineer has additional authority in the administration of the water resources within a designated groundwater basin.
Source Data: Office of the State Engineer, Nevada Division of Water Resources, Department of Conservation and Natural Resources.