Hawaii water resource region
# Hawaii water resource region

The Hawaii water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers.

The Hawaii region, which is listed with a 2-digit hydrologic unit code (HUC) of 20, has an approximate size of 6,428 square miles (16,650 square kilometers), and consists of 9 subregions, which are listed with the 4-digit HUCs 2001 through 2009.

This region includes the drainage within the state of Hawaii. Includes all of Hawaii.

## List of water resource subregions

| Subregion HUC | Subregion Name | Subregion Description | Subregion Location | Subregion Size | Subregion Map |
| - | - | - | - | - | - |
| 2001 | Hawaii subregion | The drainage on the island of Hawaii; and associated waters. | Hawaii | 4,030 sq mi (10,400 $km^2)$ | HUC2001 |
| 2002 | Maui subregion | The drainage on the island of Maui; and associated waters. | Hawaii | 730 sq mi (1,900 $km^2)$ | HUC2002 |
| 2003 | Kahoolawe subregion | The drainage on the island of Kahoolawe; and associated waters. | Hawaii | 45 sq mi (120 $km^2)$ | HUC2003 |
| 2004 | Lanai subregion | The drainage on the island of Lanai; and associated waters. | Hawaii | 140 sq mi (360 $km^2)$ | HUC2004 |
| 2005 | Molokai subregion | The drainage on the island of Molokai; and associated waters. | Hawaii | 260 sq mi (670 $km^2)$ | HUC2005 |
| 2006 | Oahu subregion | The drainage on the island of Oahu; and associated waters. | Hawaii | 630 sq mi (1,600 $km^2)$ | HUC2006 |
| 2007 | Kauai subregion | The drainage on the island of Kauai; and associated waters. | Hawaii | 560 sq mi (1,500 $km^2)$ | HUC2007 |
| 2008 | Niihau subregion | The drainage on the islands of Niihau and Kaula; and associated waters. | Hawaii | 72 sq mi (190 $km^2)$ | HUC2008 |
| 2009 | Northwestern Hawaiian Islands subregion | The drainage on Kure, Laysan, Lisianski, Necker, and Nihoa Islands; Gardner Pinnacles; Maro, and Pearl and Hermes Reefs; French Frigate Shoals; and other islets, reefs, and associated waters northwest of Niipau Island. | Hawaii | Less than 10 sq mi (26 $km^2)$ | HUC2009 |
