Two days after it ended restricted water deliveries to its member agencies thanks to improved statewide supply, the Metropolitan Water District of Southern California on Thursday began a $2.2 million advertising effort to encourage residents to continue conserving. “El Nino helped, but after drawing down our reserves the last four years to record low levels, we all must continue using water as wisely as possible to rebuild those reserves and be prepared for what lies ahead,” MWD General Manager Jeffrey Kightlinger said.