Lake Mission Viejo is a reservoir created for recreation in Mission Viejo, Orange County, California. The reservoir is formed by an earthfill dam across the canyon of Oso Creek, which is part of the Trabuco Creek and San Juan Creek drainage basin. The lake is not fed by urban runoff; it is maintained so as to be safe for contact. The Lake Association owns and operates the Lake facilities which include approximately 124 surface acres of water and 50 acres of land, including Playa del Norte (North Beach) and Marina, Playa del Este (East Beach), parking facilities, Market on the Lake Dock and dam. Recreational facilities available for Lake Association members include the Lake, two large beaches and picnic areas, clubhouse rental, boat launching facility and shoreline fishing area.
The Lake Mission Viejo Association, is a California Non-Profit corporation consisting of those residential property owners within the ultimate boundaries of the Mission Viejo planned community. Association members have access to the Lake through the guard gates at both North and East beach. Other portions of the shoreline have been developed as private residential projects and commercial village (Market on the Lake). Smaller private beach facilities around the Lake are for the exclusive use of waterfront homeowners. Costs and operations of any private facilities for lakefront developments will be paid for and are the responsibility of that lakefront owner. Other amenities include, Fishing, recreation (boating and swimming) as well as Concerts, Movie Nights and Summer Camps during the summer months. Lake Mission Viejo is a private recreational facility/ HOA that is for the use and enjoyment of members that own or live in Lake Member Properties within the city of Mission Viejo.
About 5 miles (8.0 km) south of Santiago Peak, a peak in the Santa Ana Mountains, the lake is surrounded by private residential (single-family and condominium) communities, and is a private membership for Mission Viejo residents. The primary marina is located in the northwestern arm of the lake. Upstream of Lake Mission Viejo is Upper Oso Reservoir, which spills downstream and into Mission Viejo in wet years.