That same year, there were 584 WWD water users spread over a total irrigable acreage of 528,718, averaging 905 acres per user.AuthorizationThe San Luis authorizing act (Public Law 86-488, 86th Congress) was signed on June 3,1960.Recent Developments - KestersonKesterson`s runoff contained high levels of salts, pesticides, and trace minerals, including selenium.