The city of San Diego’s plan to replace every water meter in the city is more than two years behind schedule, millions of dollars over budget and probably won’t be finished for at least another three years, according to a city audit released Thursday. The audit, prompted in part by a Voice of San Diego and NBC 7 Responds investigation, gives new insight into the city’s outrageous lack of planning for a multimillion-dollar project involving one of the most basic municipal services: water. For years, the city has wanted to install over a quarter-million new “smart” water meters, which are supposed to increase billing accuracy, provide real-time data on water use and eliminate the need for city employees to go to homes and offices across the city to read each meter.