And dam in Morgan Hill. It's the one and only time the media will be allowed in before it's completed. NBC's Ian Cull explains the importance of this $2 billion project. Reporter Today we were invited inside an 1800 foot tunnel being dug underneath the Anderson Dam to see the latest progress about four and a half football fields in above us is actually the dam at the surface. Ryan McCarter is the project manager for the Anderson Dam Seismic Retrofit. He says a large steel pipe will go inside the 20 foot wide tunnel. It will allow valley water to better control the amount of water being released from the reservoir to Coyote Creek, something that may have prevented the South Bay floods in 2017. Back then, water managers couldn't release water fast enough during a storm, leading to a spill over that triggered devastating flooding in San Jose. The new valve will be able to release 15 times more water than the current system when storms stack up successively. When we can't empty the reservoir back down to allow space for the next storm, that's when we run into issues. So this will give us the ability to lower after a storm prior to an additional storm. So far, 1400 feet have been excavated right up until this point. The final phase of this digging project kicks off in the summer. That's when they'll be boring through the final 350ft right into the reservoir. So this is the point at which we change types of equipment and we use a micro tunnel boring machine, which is basically a giant drill. So it's an eight foot diameter machine that has a cutter head at the front of it. It's all part of a major retrofit for the aging dam. That retrofit was mandated by the federal government after studies found the structure could fail in a major earthquake. Once completed, it would help ensure public safety, protect our regional water supply, and provide environmental benefits for future generations. This is all designed to take the largest possible earthquake and the largest possible flood that we could dream up. The valve will also keep the water level low through the rest of the retrofit . While the entire project isn't set to finish until 2032, for this phase, there's finally light at the end of the tunnel
