BISMARCK, N.D. (AP) — Electric power generation from Missouri River dams fell below average last year.

The U.S. Army Corps of Engineers says energy production from the six dams in the Dakotas, Montana and Nebraska totaled 8.5 billion kilowatts of electricity last year, down more than 1 billion kilowatts from the year before.

Corps spokesman Mike Swenson says more water was kept in upstream reservoirs last year to balance the river system. He says Missouri River reservoirs are at ideal levels now.

The shortfall in electricity production last year meant the Western Area Power Administration spent more than $67 million buying energy from other, more expensive sources to help make up the shortfall.

That higher cost is ultimately passed to ratepayers.