Exploring Idaho

What do you know about Idaho's water and land?

Here are some arcane facts from the Idaho Department of Water Resources.  Perhaps you can use them some time to impress your students!

State water surface area 880 square miles
Number of lakes More than 2,000
Largest lake - Pend Oreille 180 square miles
Miles of streams and rivers 93,000 miles
Longest river - Snake River 779 miles
Average annual precipitation Varies from 10 to over 50 inches
Annual stream inflow to state About 37 million acre-feet
Annual stream outflow from state About 75 million acre-feet
Irrigated area of state 4 million acres
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
Total land area 83,557 square miles
Federal land ownership 63.8 percent
State/county/city land ownership 5.2 percent
Private land ownership 31.0 percent

Now here is some information to make sense of acre-feet and related information.

  "Water Conversion Factors"

1 acre-foot   Enough water to cover 1 acre of land 1 foot deep
1 acre-foot   43,560 cubic feet
1 acre-foot   325,850 gallons
1 million gallons   3.0689 acre-feet
10 cents per 1,000 gallons   $32.59 per acre-foot
1 cubic foot (cf) 7.4805 gallons 62.37 pounds
1 cubic foot/second  448.83 gallons/minute 26,930 gallons/hour
1 cubic foot/second  646,315 gallons/day 1.9835 acre-feet/day
1 miner's inch 9 gallons per minute 0.02 cubic feel per second

More information is available at the 
Idaho Department of Water Resources at (208) 327-7900


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by
Katherine A. Young and Virgil M. Young
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in cooperation with Boise State University