From the top of Newell Creek Dam, the water level of Loch Lomond Reservoir looks particularly low. Steep, gravely banks stretch between the trees and the water.

On one side of the reservoir, a crane and a drilling rig sit on floating docks, surrounded by shipping containers and other heavy machinery. The City of Santa Cruz is replacing the pipeline that brings water in and out of Loch Lomond. But the project managers worry that if the water level drops much lower, the construction equipment could get stuck.