Administrative Basins

IDWR has divided the state into more than 50 uniquely numbered administrative basins in order to coordinate water management activities. Each basin is assigned to one of the four IDWR regions.


map of IDWR Administrative Basins

NORTHERN REGION
03, 81, 82, 83, 84, 85, 86, 87, 91, 92, 93, 94, 95, 96, 97, 98


WESTERN REGION
02, 03, 51, 55, 57, 61, 63, 65, 67, 69, 77, 78, 79


SOUTHERN REGION
01, 36, 37, 41, 43, 45, 47, 71, 72


EASTERN REGION
01, 11, 13, 15, 17, 21, 22, 23, 24, 25, 27, 29, 31, 32, 33, 34, 35, 73, 74, 75