Cedar Hills » A weekend computer malfunction caused an accidental flood in a Cedar Hills neighborhood after a city water tank released tens of thousands of gallons of water.

The flood of water -- along with rocks, mud and other debris -- streamed down a mountainside to Canyon Road about 9:30 a.m. Saturday.

Residents who spoke with city staff say it is believed that a computer monitoring system failed to shut down the water tank's pumps when the tank was full. The glitch may have been caused by a brief electrical storm late Friday night.

Pumps on the city's water tanks produce 7,000 gallons of water a minute.

Most of the water stayed in a flood channel built by the city, although a clog in the channel forced some water into the front yard and driveway of one home.