Hawaii Region HUC 20
The Hawaii Region hydrologic region spans Hawaii and is divided into 19 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
71
Moderate
Drought index
9
Abnormally dry
Area in D2+
0%
0 sub-basins ≥50%
Gauges below normal
6%
of 69 reporting
Water assets
6,820
avg WIS 42.7
Sub-basins
19
2,003 alerts · 0 transfers
quality 43drought 98streamflow 85regulatory 79coverage 51
Sub-basins, driest first
| Sub-basin | Assets | Avg WIS | Drought | Gauges low | Flow pct | Health |
|---|---|---|---|---|---|---|
| Hawaii 20010000 · HI | 1,175 | 42.4 | Abnormally dry (17) | 0% | p84 | 73 |
| Oahu 20060000 · HI | 2,902 | 42.7 | None (0) | 6% | p73 | 76 |
| Kauai 20070000 · HI | 1,266 | 42.7 | None (0) | 10% | p71 | 73 |
| Maui 20020000 · HI | 1,169 | 43.1 | None (0) | 0% | p75 | 77 |
| Molokai 20050000 · HI | 283 | 42.3 | None (0) | 20% | p59 | 74 |
| Lanai 20040000 · HI | 21 | 42.5 | None (0) | — | — | 71 |
| Kahoolawe 20030000 · HI | 1 | 41 | None (0) | — | — | 70 |
| Niihau 20080001 · HI | 3 | 42 | no data | — | — | 42 |
| Kaula 20080002 · HI | 0 | — | no data | — | — | — |
| Nihoa Island 20090001 · HI | 0 | — | no data | — | — | — |
| Necker Island 20090002 · HI | 0 | — | no data | — | — | — |
| French Frigate Shoals 20090003 · HI | 0 | — | no data | — | — | — |
| Gardner Pinnacles 20090004 · HI | 0 | — | no data | — | — | — |
| Maro Reef 20090005 · HI | 0 | — | no data | — | — | — |
| Laysan Island 20090006 · HI | 0 | — | no data | — | — | — |
| Lisianski Island 20090007 · HI | 0 | — | no data | — | — | — |
| Pearl and Hermes Atoll 20090008 · HI | 0 | — | no data | — | — | — |
| Midway Islands 20090009 | 0 | — | no data | — | — | — |
| Kure Atoll 20090010 · HI | 0 | — | no data | — | — | — |
Top water assets in this region
- 77Deep Basal Fossil Aquifer — Big Island HawaiiHawaii
- 72Hawaiian Volcanic-Rock Aquifer — Pearl Harbor Basin (Oahu)Oahu
- 72Hawaiian Volcanic-Rock Aquifer — Maui Central ValleyMaui
- 68Hawaiian Sedimentary Aquifer — Oahu CaprockOahu
- 67AlexanderKauai
- 67Kawainui Stream Nr Kamuela, HiHawaii
- 67Waikoloa Stream Nr Kamuela, HiHawaii
- 67Waikoloa Str At Marine Dam Nr Kamuela, HiHawaii
- 67Ef Kawela Gulch Nr Kamalo, Molokai, HiMolokai
- 67Waialae Str At Alt 3,820 Ft Nr Waimea, Kauai, HiKauai