View of earth dikes for the Detroit water supply system. Printed on front: "City of Detroit. Department of Water Supply. Intake system for additional supply. Intake lagoon. Contract RC-9. Dunbar & Sullivan Dredging Co., contractors. Photo no. 17. Date: 4-22-30. Photo by Manning Brothers." Typed on back: "View looking upstream showing earth dikes enclosing area to be filled to form bathing beach at head of Belle Isle. Note flume at extreme right. See photo #18 for plainer view."