Like many governors before him, Gov. Gavin Newsom is seeking to get his arms around California’s myriad water problems, issuing an executive order Monday that calls for his administration to do nothing less than ensure safe and sufficient water for the next century. The order directs state agencies to review and come up with plans to improve policies addressing such issues as California’s chronic water shortages, contaminated drinking water, unaffordable water rates, and the declining health of rivers and lakes.