What happens in a power outage?

A home supplied directly by adequate municipal pressure needs no electricity at the house to operate its sprinklers. Local water systems maintain pressure through a mix of tanks, pumps and backup power: Arvada reports nine water tanks and six pump stations, and the Southwest Metropolitan Water and Sanitation District documents automatic generator backup at its Hogback Pump Station. That said, continued pressure cannot be guaranteed in every outage. Indian Hills Water District reports that an extended electrical outage did cause a loss of pressure. Homes on a private well or an electric sprinkler pump need their supply and any backup arrangement evaluated as part of the design. Even where a sprinkler pump loses power, the pressure and water remaining in the system will often still discharge, buying some protection.