Two flash-flood-warning gauges have been installed in Havasu Creek to provide early alerts to hikers, campers and members of the Havasupai tribe whose remote village, Supai, at the bottom of the Grand Canyon has been subjected to repeated and dangerous flash floods. The Arizona Department of Water Resources led a multiagency effort to install the $60,000 worth of gauges after a flash flood on Aug. 15 forced the emergency evacuation of several hundred tribal members and tourists camping near the spectacular Havasu Falls. The flood destroyed hiking trails and a campground. Gov. Janet Napolitano signed the Havasupai Reservation Declaration in October, directing state agencies with available resources to assist the tribe, whose economy depends on tourism. The tribe has also received a $1 million donation from the San Manuel Band of Serrano Mission Indians, near Highland, Calif., to help rebuild the campground, foot bridges and hiking trails. The tribe expects to reopen the campground by May 1.