Aquifer facts

The aquifer begins in Idaho between Spirit Lake and Lake Pend Oreille. Aquifer water flows south until it reaches the middle of Rathdrum Prairie, where it turns west and flows into Washington under the Spokane Valley. When the aquifer reaches downtown Spokane, most of it turns north, flows under the city and discharges into the Little Spokane River in the form of springs.

This ancient geological feature, sculpted during Ice Age floods, was “discovered” by humans in 1895.

The aquifer covers 322 square miles in two states and flows underground, away from sight, for most of its length.

The aquifer and the Spokane River exchange water several places along its route.

The average daily water withdrawal is about 146 million gallons.

The volume of the entire aquifer is about 10 trillion gallons, making it one of the most productive aquifers in the United States.

Source: The 2004 Spokane Valley-

Rathdrum Prairie Aquifer Atlas