California’s Irvine Lake will be drained for five years as crews repair its 93-year-old dam

Orange County’s largest freshwater lake is set to remain empty for five years as local water managers prepare to drain Irvine Lake for major safety repairs to a 93-year-old dam. The 750-acre reservoir was created in 1933 after the Santiago Creek Dam was built. It will begin a gradual drawdown this month. According to reporting by SFGATE, the Irvine Ranch Water District will lower the lake’s water level from 735 feet to about 720 feet. This will reduce the amount of stored water from 2,800 acre-feet to just 300 acre-feet. The remaining water will stay in the lake until next summer. Contractors will then drain the basin completely to begin structural repairs on the aging dam. he five-year construction plan aims to improve aging infrastructure, address safety risks identified by regulators, and increase the lake’s long-term water storage capacity.Upgrading an extremely high hazard damThe California Division of Safety of Dams has classified the Santiago Creek Dam as having an "Extremely High" downstream hazard level. Because of structural weaknesses, state inspectors have limited the maximum amount of water the lake can hold in recent years. Official details published by project manage...