Great Basin Region HUC 16
The Great Basin Region hydrologic region spans California, Idaho, Nevada, Oregon, Utah and is divided into 71 HUC8 sub-basins. Conditions are the US Drought Monitor's weekly area coverage and the day-of-year streamflow percentiles of the USGS gauges inside each sub-basin, as of 2026-10-21.
Health score
61
Moderate
Drought index
269
Severe
Area in D2+
60.9%
40 sub-basins ≥50%
Gauges below normal
48%
of 215 reporting
Water assets
88,823
avg WIS 52.1
Sub-basins
71
3,757 alerts · 17,161 transfers
quality 52drought 46streamflow 61regulatory 97coverage 71
Sub-basins, driest first
| Sub-basin | Assets | Avg WIS | Drought | Gauges low | Flow pct | Health |
|---|---|---|---|---|---|---|
| Skull Valley 16020305 · UT | 253 | 45.3 | Exceptional (400) | — | — | 33 |
| Rush-Tooele Valleys 16020304 · UT | 1,864 | 48.1 | Extreme (398) | 100% | p11 | 29 |
| Middle Sevier 16030003 · UT | 2,496 | 55.2 | Extreme (394) | 67% | p5 | 37 |
| Lower Sevier 16030005 · UT | 4,113 | 50.7 | Extreme (385) | 100% | p6 | 26 |
| San Pitch 16030004 · UT | 1,369 | 53.2 | Extreme (381) | 100% | p8 | 27 |
| Pilot-Thousand Springs, Nevada, Utah 16020307 · NV, UT | 458 | 58.7 | Extreme (379) | — | — | 41 |
| Utah Lake 16020201 · UT | 2,518 | 48.5 | Extreme (370) | 67% | p13 | 39 |
| North Fork Humboldt 16040102 · NV | 493 | 64.8 | Extreme (356) | 100% | p12 | 43 |
| Curlew Valley 16020309 · ID, UT | 1,239 | 46.1 | Extreme (345) | — | — | 39 |
| Spanish Fork 16020202 · UT | 2,125 | 51.4 | Extreme (338) | 25% | p30 | 54 |
| Lower Bear-Malad 16010204 · ID, UT | 1,566 | 48.1 | Extreme (335) | 100% | p13 | 34 |
| Upper Humboldt 16040101 · NV | 1,629 | 60.1 | Extreme (333) | 73% | p15 | 46 |
| Little Humboldt 16040109 · NV | 917 | 55.9 | Extreme (330) | 40% | p25 | 52 |
| Great Salt Lake 16020310 · UT | 112 | 43.5 | Extreme (329) | 0% | p60 | 57 |
| Southern Great Salt Lake Desert 16020306 · NV, UT | 1,414 | 47.4 | Extreme (323) | 0% | p45 | 59 |
| Northern Great Salt Lake Desert 16020308 · NV, UT | 1,646 | 49.3 | Extreme (320) | 100% | p9 | 30 |
| Lower Beaver 16030008 · UT | 172 | 53 | Extreme (308) | — | — | 46 |
| Jordan 16020204 · UT | 2,184 | 48 | Extreme (300) | 33% | p48 | 54 |
| Beaver Bottoms-Upper Beaver 16030007 · UT | 1,914 | 49.7 | Extreme (300) | 0% | p28 | 61 |
| Middle Humboldt 16040105 · NV | 1,199 | 55.6 | Extreme (300) | 100% | p5 | 37 |
| Long-Ruby Valleys 16060007 · NV | 737 | 54.2 | Extreme (300) | — | — | 47 |
| South Fork Humboldt 16040103 · NV | 469 | 59.1 | Extreme (300) | 100% | p12 | 40 |
| Dry Lake Valley 16060009 · NV | 368 | 52.6 | Extreme (300) | 100% | p2 | 32 |
| Rock 16040106 · NV | 364 | 62.5 | Extreme (300) | 100% | p0 | 36 |
| Pine 16040104 · NV | 294 | 58.6 | Extreme (300) | 71% | p10 | 48 |
| Little Smoky-Newark Valleys 16060006 · NV | 214 | 50.1 | Extreme (300) | — | — | 45 |
| Tule Valley 16020303 · UT | 74 | 44.2 | Extreme (300) | — | — | 42 |
| Spring-Steptoe Valleys 16060008 · NV | 1,565 | 54.6 | Severe (297) | 100% | p16 | 44 |
| Sevier Lake 16030009 · UT | 181 | 46.4 | Severe (297) | — | — | 44 |
| Provo 16020203 · UT | 1,544 | 51.9 | Severe (292) | 14% | p32 | 58 |
| Lower Humboldt 16040108 · NV | 1,192 | 53.9 | Severe (288) | 100% | p10 | 41 |
| Diamond-Monitor Valleys 16060005 · NV | 1,075 | 51.7 | Severe (288) | 100% | p8 | 38 |
| Middle Bear 16010202 · ID, UT | 1,451 | 49.6 | Severe (285) | 50% | p27 | 53 |
| Reese 16040107 · NV | 1,075 | 54.6 | Severe (282) | — | — | 49 |
| Upper Quinn 16040201 · NV, OR | 2,449 | 58.8 | Severe (280) | 50% | p19 | 51 |
| East Fork Sevier 16030002 · UT | 1,305 | 56.3 | Severe (274) | 100% | p10 | 36 |
| Hot Creek-Railroad Valleys 16060012 · NV | 1,073 | 51.1 | Severe (273) | 100% | p16 | 44 |
| Northern Big Smoky Valley 16060004 · NV | 477 | 52.8 | Severe (266) | 0% | p26 | 65 |
| Lower Weber 16020102 · UT | 3,609 | 49.9 | Severe (265) | 75% | p19 | 47 |
| Bear Lake 16010201 · ID, UT | 662 | 43.9 | Severe (263) | 100% | p8 | 32 |
| Dixie Valley 16060001 · NV | 1,326 | 52 | Severe (259) | — | — | 50 |
| Hamlin-Snake Valleys 16020301 · NV, UT | 1,175 | 54.8 | Severe (250) | 0% | p81 | 62 |
| Sand Spring-Tikaboo Valleys 16060014 · NV | 3,885 | 44.7 | Severe (249) | — | — | 47 |
| Escalante Desert 16030006 · NV, UT | 3,521 | 49.8 | Severe (249) | 0% | p81 | 60 |
| Little Bear-Logan 16010203 · ID, UT | 1,765 | 51 | Severe (227) | 80% | p10 | 47 |
| Upper Sevier 16030001 · UT | 1,383 | 56.4 | Severe (222) | 0% | p33 | 69 |
| Granite Springs Valley 16050104 · NV | 280 | 48.5 | Severe (219) | — | — | 52 |
| Pine Valley 16020302 · UT | 301 | 46.9 | Severe (218) | — | — | 52 |
| Central Bear 16010102 · ID, UT, WY | 286 | 54.7 | Severe (217) | 100% | p9 | 39 |
| Gabbs Valley 16060002 · NV | 361 | 54.2 | Severe (211) | — | — | 56 |
| Upper Weber 16020101 · UT, WY | 1,895 | 54.5 | Severe (209) | 40% | p28 | 59 |
| Carson Desert 16050203 · NV | 1,597 | 45.2 | Severe (205) | 0% | p37 | 66 |
| Lower Quinn 16040202 · NV | 2,496 | 59.5 | Severe (202) | — | — | 60 |
| Upper Bear 16010101 · UT, WY | 2,948 | 58.9 | Severe (200) | 40% | p53 | 62 |
| Smoke Creek Desert 16040203 · CA, NV | 2,008 | 60.3 | Severe (200) | — | — | 60 |
| Massacre Lake 16040204 · CA, NV | 916 | 59.5 | Severe (200) | — | — | 60 |
| Ivanpah-Pahrump Valleys 16060015 · CA, NV | 864 | 46.6 | Severe (200) | — | — | 53 |
| Thousand-Virgin 16040205 · NV, OR | 726 | 59.3 | Severe (200) | — | — | 60 |
| Cactus-Sarcobatus Flats 16060013 · NV | 590 | 48.4 | Severe (200) | — | — | 54 |
| Pyramid-Winnemucca Lakes 16050103 · NV | 373 | 51.6 | Severe (200) | 0% | p74 | 69 |
| Southern Big Smoky Valley 16060003 · NV | 339 | 57.2 | Severe (200) | — | — | 59 |
| Ralston-Stone Cabin Valleys 16060011 · NV | 457 | 54.2 | Moderate (199) | — | — | 57 |
| Truckee 16050102 · CA, NV | 2,126 | 48.2 | Moderate (185) | 13% | p46 | 66 |
| Middle Carson 16050202 · NV | 775 | 46.2 | Moderate (181) | 0% | p31 | 68 |
| Lake Tahoe 16050101 · CA, NV | 933 | 56.1 | Moderate (160) | 40% | p27 | 62 |
| Fish Lake-Soda Spring Valleys 16060010 · CA, NV | 987 | 53.2 | Moderate (146) | — | — | 62 |
| Walker 16050303 · NV | 663 | 47.7 | Moderate (129) | 13% | p54 | 70 |
| Upper Carson 16050201 · CA, NV | 2,408 | 48.6 | Moderate (122) | 55% | p24 | 62 |
| Walker Lake 16050304 · NV | 224 | 48.5 | Moderate (108) | 0% | p51 | 74 |
| West Walker 16050302 · CA, NV | 777 | 52 | Moderate (100) | 33% | p43 | 68 |
| East Walker 16050301 · CA, NV | 579 | 58.3 | Moderate (100) | 43% | p33 | 66 |
Top water assets in this region
- 80009 N42 E19 23Bccc1Massacre Lake
- 80009 N44 E19 30Aa 1Massacre Lake
- 78029 N44 E30 24Dbaa1Lower Quinn
- 78031 N40 E35 21Bbca1Upper Quinn
- 78Nevada Water RightMassacre Lake
- 78030A N44 E34 20Aabb1Upper Quinn
- 78030A N45 E33 13Bbcc1Upper Quinn
- 78Cottonwood CreekSmoke Creek Desert
- 78Pennington WellMassacre Lake
- 78031 N40 E33 22Adcd1Upper Quinn