The careful planning, innovation and cooperation of local agencies over 40 years ago turned a once fenced-off reservoir into a beautiful 55 acre public park that thousands of people enjoy every year.

Harry Griffen Park is dedicated to Helix Water District’s long-time board member and board president, who served from 1951 through 1978. During his 27 years of oversight, Mr. Griffen saw the district’s rapid expansion and growth, its construction and filling of Lake Jennings and the completion of the district’s R.M. Levy Treatment Plant in Lakeside, and he was instrumental to securing water supplies from Northern California for San Diego.

The park itself began as a storage reservoir, originally built in 1893. First known as Murray Hill Reservoir and later renamed to Grossmont Reservoir, it was used as a terminus reservoir for water diverted from Lake Cuyamaca to East County. The water arrived via the San Diego Flume, which started just east of the El Monte Valley and flowed by gravity for 33 miles into the reservoir.

In 1957, the reservoir was expanded to meet the region’s growing demand for water, caused by the post-war era population boom, and lined to improve water quality. But as the area grew, subdivisions and developments encroached on this once isolated reservoir and created a larger potential for contamination. Knowing of this vulnerability, Helix decided to fully enclose the reservoir and began construction of a new reinforced concrete reservoir in 1976.

The new structure was completed in 1978, is 600 feet long, 358 feet wide and 22 feet high. It is out of sight to the public today because it is buried below the grassy field within Harry Griffen Park.

Once the reservoir was completed, Helix initiated a Joint Powers Authority to form, fund, operate and maintain a master-planned regional park with Grossmont Union High School District, the County of San Diego and the cities of El Cajon and La Mesa. This partnership still lasts today and is a model for inter-agency cooperation for the benefit of the communities the agencies serve.