Idaho Water Facts

State Water Surface Area ------------------------------------ 880 Square Miles
Number Of Lakes ------------------------------------------- More Than 2,000
Largest Lake -- Pend Oreille -------------------------------- 148 Square Miles
Deepest Lake -- Pend Oreille ------------------------------- More Than 1,100 Feet
Highest Waterfall--------------------- 600 feet, Big Fiddler Creek, Boise River Basin
Miles Of Streams and Rivers -------------------------------- 93,000 Miles
Longest River -- Snake River ------------------------------- 779 Miles
Average Annual Precipitation --------Varies From Less than 10 to More than 60 Inches
Most Precipitation in 24-Hour Period----- 7.7" of rain, Rattlesnake Creek, Idaho, 1909
Annual Stream Inflow to State ------------------------------ About 37 Million Acre-feet
Annual Stream Outflow to State----------------------------- About 75 Million Acre-feet
Irrigated Area of State -------------------------------------- 4 Million Acres
Highest Dam----------------------------- Dworshak, North Fork Clearwater, 717 feet.
Active Reservoir Storage Capacity ------------------------- 12,384,000 Acre-feet
Largest Active Storage Reservoir -- Dworshak ------------- 2,016,000 acre-feet
Snake Plain Aquifer Storage -- Top 100 Feet of Aquifer -- About 100 Million Acre-feet