What whispers do you hear near the Willow Tree Dam? This isn’t just any dam. Willow Tree Dam has a story etched in stone and flowing through its waters. I will tell you all about Willow Tree Dam now.
Old Mission Dam shares a lineage with this area. It stands as one of the first major irrigation projects on the Pacific coast. The City of San Diego owns and manages this significant historical site. Old Mission Dam impounded water from the San Diego River. For much of the year it provided a reliable water supply. This water was crucial for agriculture and domestic use. The Mission of San Diego de Alcalá depended on it.
Father Junípero Serra founded the San Diego de Alcalá Mission in 1769. It was the first of 21 California missions. In 1774, Serra relocated the mission seeking better water access. He also wanted to distance his Indian converts from the Presidio garrison. Despite a native rebellion in 1775, the mission prospered. By 1800, over 1,500 Indian neophytes called the mission home. Earthquake damage in 1803 prompted reconstruction and expansion. By 1813, the mission assumed its present form. The mission reached its peak population in 1824 with 1,829 Indians. In 1835, the Mexican government secularized the mission. Neglect and deterioration followed.
Construction dates for Old Mission Dam remain uncertain. It likely began around 1803 after a two-year drought. By 1817, the dam had certainly taken its final shape. This solid masonry structure measured about 220 feet wide. It was 13 feet thick at the bottom and at least 12 feet high. Native stone and locally made cement formed the dam, aqueduct, and flume. The flume carried water 5 miles to the mission’s gardens and vineyards. It was 2 feet wide and 1 foot deep.
By 1867, the dam and aqueduct system lay in ruins. However, they were repaired around 1874. They were put back into use for a time. Today, the dam’s remains still impress. They impound a small amount of water. The dam will be part of San Diego’s proposed Fortuna Mountain-Mission Gorge Metropolitan Park. Visible remains of the aqueduct or flume are scarce now. San Diego Mission has undergone extensive reconstruction since 1931. The Old Mission Dam was designated a National Historic Landmark in 1963.
The Old Mission Dam is located about 5 miles northeast of the Mission San Diego de Alcalá. It crosses the San Diego River. The river was historically seasonal drying up in the summer. The dam ensured water releases even when the river ran dry. A tile channel minimized water loss in the sandy soil. Only fragments of this channel remain. The drought of 1800-1802 likely spurred the dam’s construction. The dam and aqueduct were reported to be in ruins in 1867. But the dam was repaired in 1874.
Now, as you stand here at Willow Tree Dam, consider its history. Think about the ingenuity that built it and its importance to early San Diego. Hear those whispers in the willow leaves above. Perhaps they are the echoes of those who depended on this water. Perhaps they are the sound of whispering elves, as the English legend says.