Water quality in San Diego County’s dozen watersheds improved overall in 2016 for the first time in three years, San Diego Coastkeeper reported Tuesday. In its 2016 San Diego County Water Quality Report, the environmental organization rated two of the watersheds to be of good quality — the San Luis Rey River in the North County and Rose Creek in San Diego. Most of the others were rated as fair. “Of course, a single year of overall better water quality readings does not mean San Diego’s water will keep improving,” said Meredith Meyers, Coastkeeper’s lab manager.