On an overcast day in May, construction is in full swing on the Charles E. Meyer Desalination Facility in this affluent enclave on the Central California coast. Several workers fine-tune rebar in foundations for processing units, while two others deploy a large spinning plate to melt the edges of an ocean intake pipe so it can be attached to another pipe. In response to California’s epic drought, the Santa Barbara City Council voted last year to reactivate a desalination plant built in 1992 to fight an earlier drought. It operated for only six weeks before being shuttered.