The silt curtains will block biological species from entering the work zones and protect water quality by containing disturbed sediment, said the San Francisco Public Utilities Commission.
Divers will begin underwater work on outlets and pipelines at depths of more than 100 feet, the commission said. All watercraft and materials entering the reservoirs will be screened to prevent non-native species and contaminants from entering the water.
The Crystal Springs Reservoir System serves as the emergency water supply for about one million people in San Mateo and San Francisco counties. The utilities commission expects the giant seismic improvement project to be completed in 2013.
Visit sfwater.org/SCT for construction updates.