Southern California continues to invest in water infrastructure to strengthen drought resilience and expand recycled water capacity. Sukut Construction has secured a $214 million contract from the Irvine Ranch Water District to deliver the Syphon Reservoir Improvement Project, a major upgrade that will significantly increase recycled water storage for the region.
The project will increase the reservoir's storage capacity from 578 acre-feet to 5,000 acre-feet, creating approximately 1.6 billion gallons of recycled water storage for agricultural irrigation, environmental uses, emergency response and future regional water demands.
As part of the work, Sukut Construction will reconstruct the existing dam by removing the current 59-foot embankment to competent bedrock before building a new 138-foot-high dam designed to meet California Department of Water Resources Division of Safety of Dams requirements.
The contractor will also install a stream diversion system capable of withstanding a 500-year storm event, along with dewatering systems and erosion control measures to protect surrounding waterways and ecosystems during construction.
The project involves extensive earthmoving operations, including excavation and reuse of approximately 2.18 million cubic yards of material for the new embankment. Construction also includes foundation improvements, installation of a 1,500-foot cutoff wall, a grout curtain requiring roughly 55,000 linear feet of drilling and grouting, and advanced monitoring systems to support long-term dam performance.
Additional work includes new inlet and outlet facilities, approximately 1,240 linear feet of 42-inch steel pipeline, spillway improvements, control and treatment buildings, access roads, utilities, public trails and landscaping.
The project also incorporates environmental restoration through the creation of new riparian woodland habitat using native vegetation to improve ecological conditions around the reservoir.
Water storage and recycled water infrastructure remain critical priorities across California as agencies invest in long-term drought resilience and resource management. For construction owners, engineers and infrastructure contractors, the Syphon Reservoir Improvement Project highlights continued opportunities in heavy civil construction, dam rehabilitation and large-scale water resource projects requiring specialized geotechnical, hydraulic and environmental expertise.
Source: Sukut Construction.
