Water Projects

Trampas Canyon Reservoir and Dam

Santa Margarita Water District
Rancho Mission Viejo, CA
$88 million (Construction)
Sukut Construction
GMU Geotechnical, Inc.
Photo Credit:
Santa Margarita Water District and Mol Goodman Photography

Butier Engineering, Inc. was selected to provide construction management and inspection services for the construction of the Trampas Canyon Dam and Reservoir. The dam and reservoir were reconstructed on 177-acres of property to create a 1.6 billion gallon recycled water reservoir. Construction consisted of new inlet/outlet structures, a spillway, micro-tunneling, instrumentation, and a new Dam control building. The project will help SMWD achieve its goal of recycling 100% of its wastewater and provide seasonal and operational storage for its existing and proposed recycled water system. The reservoir will supply irrigation demands for customers in Talega Valley and in Rancho Mission Viejo’s (RMV) ongoing Ranch Plan development, as well as other existing irrigation demands in South Orange County. Recycled water will be supplied by the Chiquita Water Reclamation Plant (CWRP) and may be supplemented with other non-domestic water (NDW) supply sources.

By the Numbers:

  • Largest recycled water reservoir in Orange County
  • 1.6 billion-gallon recycled water reservoir = 2,500 Olympic-size swimming pools
  • $109 million (total project cost)
  • $93 million (construction cost)
  • 3,000 feet long from the east dam to the west side of the reservoir
  • 2,700 feet from back of reservoir to the dam
  • Deepest Point: 88 feet
  • Face of Dam: 216 feet high
  • Surface Area: 177 acres
  • Dam was built 40 feet higher than it previously was
  • 4.3 million cubic yards of grading and excavation
  • 41 million gallons of rainwater removed by construction teams due to 2018 storms

Virtual Tour of Trampas Canyon Dam & Reservoir (courtesy of Santa Margarita Water District):


Vast new reservoir in south Orange County gets its first drops of water

Santa Margarita Water District Holds Virtual Dedication for Trampas Canyon Dam and Reservoir

New Trampas reservoir in south O.C. overcoming hurdles; public tours offered May 4

The Big Dig: Trampas Canyon Reservoir to Serve as South County’s Largest Water Project