Lower Otay is a reservoir located in San Diego County, California. The reservoir was created in 1918 when the Lower Otay Dam was constructed to provide water to the growing city of San Diego. The reservoir is fed by the Otay River, and it also receives water from the Colorado River via the All-American Canal. The reservoir is used for agricultural irrigation, municipal water supply, and recreational activities such as fishing, boating, and hiking. The water levels in the reservoir are influenced by both surface flow and snowpack, with the latter being particularly important in dry years. The reservoir is managed by the Otay Water District, and it plays a critical role in providing water to the surrounding communities.