A $1.2 billion project to rebuild the largest dam in Santa Clara County to reduce the risk of it failing in a major earthquake has finally begun to make significant visible progress, as construction crews have started to dig a huge new outlet tunnel at Anderson Dam near Morgan Hill. The tunnel, which will be 24 feet high and 1,700 feet long, will allow the sprawling reservoir east of Highway 101 to be drained more quickly in the event of an earthquake, extreme storm or other incident. After the tunnel is finished in late 2024, and a 13-foot high pipe installed inside, crews will tear down the existing 240-foot earthen dam, built in 1950. They will then build a new dam and concrete spillway, capable of surviving a 7.2 magnitude earthquake.