Built in 1918 in one of Carlsbad's oldest neighborhoods, the Buena Vista Reservoir served surrounding agricultural fields and the farming community. Starting in the 1940s, it stored water pumped through the Mission Basin transmission pipeline from a groundwater well near the former Valley Drive-In theater in Oceanside. The reservoir ceased operations in the 1960s, and the site remained dormant until neighbors led an effort to create the park. The reservoir covered 3/4 acre and held 1.5 million gallons, enough water to supply an average household for 50 years. It supplied water to local avocado orchards, supporting the annual Avocado Days Festival. Some parts of the old reservoir remain, including the water tank left in place as a homage to its history, and much of the concrete bottom remains beneath the large grassy area to reduce impacts to nearby landfills. The park's landscaping uses nearly 30 California-native plant species that require significantly less water while providing habitat for local wildlife.