Hydraulic Studies and Operating Results on the Miami Flood Control System

The flood control system of the Miami Conservancy District, a description of which has been published,‡ consists of a combination of retarding basins and channel improvements. The dams and retarding basins are five in number, while channel improvements were carried out in eight cities and towns.The purpose of this paper is to state as fully as possible the results obtained thus far (1928) in the operation of the works of the District. The observations and measurements made to check the design are recorded.The complete system has been in operation since 1922. Sufficient time therefore has not elapsed to make definite conclusions possible in all respects; but it is thought best to report at the present time and make known such information as is now available.In general, the assumptions on which the designs of dams, conduits, and channels were based, have been confirmed. The discharge of the conduits under given heads has been so mew hat larger than the quantities used in the calculations, but this was expected while the conduits were new. The outlet structures have fully met the requirements for dissipating the energy of the water as it leaves the conduits.The improved channels at Dayton and Hamilton, Ohio, have maintained themselves better than was anticipated. The construction of cut-off channels has been justified. The dams at Dayton and Hamilton together with the gravel plants have greatly reduced the cost of channel maintenance.Valuable information has been secured from the rainfall and run-off records. Additional information could be secured by the use of a number of recording rain gauges and recording back-water gauges at the dams.