Canals, Tunnels and Penstocks

California DWR updates on proposed Delta Conveyance Project

California DWR updates on proposed Delta Conveyance Project
Harvey O. Banks Delta Pumping Plant (photo courtesy California DWR)

The California Department of Water Resources has provided an update and details on its Delta Conveyance Project, a proposed tunnel system designed to protect against interruptions in water deliveries due to natural events.

The State Water Project provides water to 29 public water agencies that serve 27 million Californians and also uses the water for hydropower generation. The SWP is a system of 32 storage facilities, 21 pumping plants, four pumping-generating plants, eight conventional hydroelectric plants and about 700 miles of canals and pipelines. Among these generating plants is the 762 MW Hyatt Powerplant at the foot of Oroville Dam.

Without modernization of this infrastructure, climate-driven weather extremes and seismic threats will affect how DWR can deliver this water, risking human health and safety, urban and agricultural economies, and the cost of water to communities.

The modernization work required includes physical infrastructure improvements to how DWR captures and moves water during high-flow weather events to store for later use during dry periods. A proposed tunnel system, called the Delta Conveyance Project, will help protect against interruptions in water deliveries due to earthquakes and the effects of climate-driven weather extremes like rising sea levels and other unanticipated extreme weather.

While alternative supplies and conservation are important for regional sustainability overall, they don’t directly address functionality of the SWP. The proposed Delta Conveyance Project is geared toward protecting and preserving the long-term viability of SWP infrastructure.

Modernizing the SWP by adding new water intakes and creating a new way to move the water does two important things:

Adapts to climate-driven weather extremes by adding flexibility in how the water moves

Protects against supply disruptions caused by nearby earthquakes

Climate change models indicate that more precipitation will fall as rain in the winter months. The state expects to see more runoff and river flows in the winter than in past years. Infrastructure built to accommodate seasonal patterns of the past cannot accommodate the flashy winter flows that are becoming more common, DWR said.

Water agencies across the state are working hard to fortify their water supply portfolios, including the 18 State Water Contractors participating in the proposed Delta Conveyance Project. This project neither precludes nor replaces those much-needed efforts, according to a release.