Trampas Canyon Reservoir & Dam

History of Trampas Canyon Reservoir

In the early 1970s, a reservoir was built as part of the sand mining operation in the hills south of Ortega Highway in Rancho Mission Viejo. More than 40 years later, Santa Margarita Water District envisioned a new use for the abandoned reservoir: to create winter storage for recycled water that could be used during dry, hot months to water landscapes.

A new era of water sustainability in south Orange County was born, as SMWD worked with Rancho Mission Viejo and acquired the land in 2017. This $123 million investment was paid for through a State Water Resources Control Board low-interest loan, a Proposition 1 grant, Rancho Mission Viejo, designated District reserves, and other funds.

How Trampas Canyon Reservoir Will Work

Trampas Canyon Reservoir will capture and store recycled water from the Chiquita Water Reclamation Plant and other recycled water supply sources. Currently, Chiquita Water Reclamation Plant is capable of producing recycled water year-round, but during the winter months water demand is so low that treated wastewater flows to the ocean. With the storage capacity of Trampas Canyon Reservoir in place, our community can now store this treated wastewater for use in the summer when demands are high. That’s why Trampas Canyon Reservoir is a real game-changer for the region!

Environmental Benefits

SMWD balances construction and operation of the reservoir with the preservation of open space and wildlife habitat. Throughout construction, biologists worked to ensure that the project would enhance the region as a continued habitat for many species of birds, invertebrates, and small and large mammals.

Toward a Water Resilient Future

Saving recycled water in the winter or wet months for use in the dry months is a key benefit of Trampas Canyon Reservoir. In the future, the reservoir may even expand our region’s drinking supply by adding recycled water to groundwater aquifers or even the drinking water system directly.