Portions of San Diego’s First Aqueduct will shut down this week for yearly inspections and maintenance of water supply pipelines for the region, the San Diego County Water Authority announced this week. The San Diego County Water Authority’s historic First Aqueduct delivers treated and untreated water from just south of the Riverside County/San Diego County border to the San Vicente Reservoir near Lakeside, transporting up to 120 million gallons of water per day to the San Diego region. Portions of the San Diego County Water Authority’s historic First Aqueduct are scheduled to shut down from Feb. 25 to March 5 as the Water Authority works to maintain a safe and reliable water supply for San Diegans.