Old Mission Dam

The Old Mission Dam is a historic water impoundment structure in Mission Trails Regional Park in San Diego, California. It was built about 1803 to impound the San Diego River to provide water for irrigation of the fields associated with the Mission San Diego de Alcalá, the first Spanish mission in what is now The State of California. It was the first major colonial-era irrigation project on the Pacific coast of the United States. The surviving remnant of the dam was designated a National Historic Landmark in 1963.