New California water regulations likely will transform much of the Coachella Valley’s landscape in coming years. But how quickly that shift will happen hinges on whether some local water suppliers win major exemptions written in to the new rules. On paper, water agencies serving the scorched desert valley could be required to cut water use by a third or more under new rules rolled out by the State Water Quality Control Board in early July. Agencies out of compliance would face fines of up to $10,000 a day. But the drastic-sounding changes won’t be enforced until 2027, and contain multiple avenues to dramatically scale back required cutbacks — caveats that infuriate some environmentalists.