Ventura County may have survived the worst of the state’s drought, but if a severe dry spell returns and lasts more than five years, most local cities will be back in serious trouble. That’s the finding of a report issued this week by the Ventura County grand jury that evaluated plans of the county’s 10 cities to see whether local officials have adequately addressed their water needs now and in the future. Several cities, according to the report, rely too much on imported water and haven’t developed plans for an emergency water shortage.