FAQs

Valley Water will begin construction in spring 2021 with the Anderson Dam Tunnel Project, which is expected to last about two years. The actual seismic retrofit will follow and is expected to be completed in 2030. 

Most seismic retrofits just add additional soil to the downstream face. Valley Water is completely removing the embankment, which needs to be done in a staged way in order to keep the dam at a minimum level to protect the downstream community. That lengthened the work out substantially to between about five to seven years. 

Because the reservoir will be out of commission for that long, there are various impacts to wildlife, sensitive species and water supply. To minimize those impacts, the project got even longer. We have to keep the creek partially wet, which will be done with imported water. Valley Water also has to work alongside 13 different regulating agencies at the federal, state and local level. 

Valley Water would love to build the dam in a shorter period of time. When originally constructed, Anderson took a year to build. Today, however, there are tighter regulations that must be followed, especially in California compared to Nevada, where Hoover is located. There's a greater understanding about construction impacts on the environment and safety standards are much more advanced than in previous years in the ways that things must be constructed. There are different things that must be complied with. In considering just the logistics of taking down a dam while it's still in service, in place and then constructing it basically from scratch, will take a while. 

It would take about four years to naturally fill Anderson Reservoir with rainfall. The reservoir, however, is connected to our untreated water distribution system that allows us to move water around the county. So if there is a period where there is not enough rain, we will use extra imported water to fill the reservoir.