Irvine Lake (formerly known as Santiago Reservoir) was formed by the Santiago Dam, built in 1931. It was constructed by The Irvine Company and Serrano Irrigation District (today know as the Serrano Water District). The lake was opened to the public for fishing in 1941.

Santiago Dam is 810 feet high and the lake stores approximately 28,000 acre feet of water. Originally the lake served the agricultural and farming communities surrounding Irvine Lake. Today the Serrano Water District provides drinking water to Villa Park and some parts of Orange. Irvine Ranch Water District uses untreated water from Irvine Lake to supplement its irrigation water only. IRWD is a partial owner of the lake, but Serrano Water District runs Irvine Lake and its concessions.

Fishing:
Irvine Lake is a quiet, scenic fishing lake nestled at the base of the Cleveland National Forest. Santiago Creek feeds the 700-acre lake that features steep rocky cliffs, shallow coves, deep creek channels, submerged high spots, overhanging trees, and provides excellent fishing and a family park environment. A fishing license is not required.

Where:
4621 Santiago Canyon Road, Silverado.
Take the Costa Mesa (55) Freeway to the Chapman Avenue East off ramp. Go east on Chapman Avenue for 9.5 miles (Chapman turns into Santiago Canyon Road). Irvine Lake is on your left.