The Detroit Water and Sewerage Department could slash more than 80 percent of its staff over the next five years in a drastic overhaul to cut costs and reduce customers’ rate increases…. If adopted, the department would go from having 1,978 employees to 374 over the next five years. Another 361 employees would still work for the department but would be outsourced through other companies, according to the proposal. Officials estimate it would save about $139 million a year in personnel costs. Most jobs would be cut through attrition, but officials said layoffs are possible….Among the departments being looked at for outsourcing: security, rate setting, grounds and facilities maintenance, office cleaning and garbage collections, some lab functions, fleet repairs, payroll, legal, print shop and billing….