The Central Valley Project (CVP) pumps water south from the Sacramento-San Joaquin Delta, and supplies about one third of the State’s irrigation water. Droughts and pumping restrictions imposed to protect fish habitats and water quality in the past two decades have created shortages and volatility in CVP water deliveries. Two public entities — the Del Puerto Water District (DPWD) and the San Joaquin River Exchange Contractors Water Authority (Exchange Contractors) who collectively supply water to 285,000 acres of farmland — have partnered to address the issue by developing the Del Puerto Canyon Reservoir.
The Del Puerto Canyon Reservoir Project, which will help bridge the water supply gap, includes an 800-acre reservoir with a 260-foot-high earthen dam and two saddle dams, conveyance and electrical facilities, road and utility relocation, and pipeline connection to the Delta-Mendota Canal. This new off-stream reservoir will provide flexible storage for up to 82,000 acre-feet of water that will benefit farmlands, wildlife refuges, and surrounding communities.
Woodard & Curran was hired to prepare a project feasibility report, an Environmental Impact Report (EIR) and Environmental Impact Statement (EIS), as well as serve as program manager to assist with design and oversee the consultants specialized in designing certain aspects of the project. The final EIR dated October 2020, developed in compliance with the California Environmental Quality Act (CEQA), includes evaluation of a myriad of resources, such as project aesthetics, agricultural and forestry resources, air quality, terrestrial and aquatic biological resources, cultural resources, energy resources, geology and soil, greenhouse gas emissions, hazards and hazardous materials, hydrology and water quality, land use and recreation, traffic and transportation, tribal cultural resources, environmental justice, and Indian trust assets. Woodard & Curran developed mitigation for potential impacts to minimize environmental effects.
In addition to collaborating with a transportation engineer for the reconfiguration of Del Puerto Canyon Road and the local power company for the relocation of transmission lines, Woodard & Curran recommended incorporating measures into the design that help maintain the natural habitat of birds, animals, and plants in the area both during and after construction. This includes managing the flow of Del Puerto Creek to maintain minimum flows downstream of the dam.
Furthermore, the project team consulted with the Native American Heritage Commission to ensure there was no disruption of sacred sites in the project area. With archeological features present in Del Puerto Canyon, the project team plans to keep lines of communication open with the tribal community during design phases and construction. The team also addressed community concerns regarding seismic activity at the site of the reservoir. The earthen fill used in the project design provides the greatest flexibility and safety during potential earthquake events.
While there have been few reservoirs constructed in California in the past 50 years, the impacts of climate change, regulatory constraints, and implications of the Sustainable Groundwater Management Act (SGMA), create a new environment favorable to reservoir projects. However, these types of projects are not a small undertaking from a practical and funding perspective. State initiatives, such as the Water Storage Investment Program (WSIP), and federal opportunities, such as the Water Infrastructure Improvements for the Nation Act (WIIN Act), have provided a more affordable approach to these types of projects.
As program manager for the reservoir, the team developed the Feasibility Report, which was included in DPWD’s application to obtain WIIN Act funding. Also included in the grant application package was a letter of support from California Governor Gavin Newsom, which helped secure a grant through the WIIN Act to fund 25 percent of the project.
With design phases still underway, construction is set to begin as soon as 2027. With due diligence during the initial assessment and design phases, Woodard & Curran has helped DPWD create a project that will secure water resources for the population and agricultural customers they serve for at least another century, helping to maintain a vibrant agricultural economy in the region.