Valley Water crews were taking advantage of the dry, sunny weather before the rains hit by completing some long-needed work at the bottom of Anderson Dam’s spillway.

Work crews were using heavy machinery to restore eroded “riprap,” a mixture of rocky material at the base of the spillway where water falls into Coyote Creek when Anderson Reservoir fills beyond its capacity, explained Valley Water spokesman Matt Keller.

The previous riprap washed downstream the last time Anderson Reservoir went over the spillway, during heavy storms in early 2017. The overflow resulted in significant flooding of Coyote Creek and neighborhoods in San Jose downstream from the reservoir.

The work underway this week is a maintenance requirement requested by the Federal Energy Regulatory Commission, one of the agencies that regulates public dams, Keller explained. The work was unrelated to recent earthquakes or the upcoming seismic retrofit of Anderson Dam.

Valley Water is the region’s water district, which provides drinking water and flood protection to 2 million Santa Clara County residents.