The flood protection system is ingeniously simple. The drainage patterns of the entire Great Miami River Watershed are incorporated into its design. The dams and levees operate without human intervention and have no moving parts, but people are necessary to maintain the system and monitor and operate floodgates during high-water events. Floodgates over storm-sewer outfalls to the river are closed during high-water events to prevent the river’s rising waters from backing up into the storm sewers into the protected areas behind the levee.

The Miami Conservancy District’s (MCD) flood-protection system was the first of its kind. It was designed to use five dry dams, meaning the dams are used only to hold back floodwaters after heavy rainfall. The remainder of the time, the land behind the dams – 35,650 acres – is used predominantly for parkland and farmland.

• The MCD flood protection system includes five dams: Germantown, Englewood, Lockington, Taylorsville and Huffman.
• The dams were constructed simultaneously between 1918 and 1922.
• The dams operate without human intervention and have no moving parts.
• Water is controlled through conduits that allow only the amount of water the channel can handle downstream. The remaining floodwaters are stored behind the dam in temporary pools.
• It cost $30.36 million to construct the original system. Careful attention to planning, financing, legislation and implementation resulted in the most comprehensive flood protection system in the nation. 
• To replace the system today, it would cost more than $912 million, based on the Engineering News Record Construction Cost Index.
• MCD employees maintain the five dams, 60 miles of levee and 37 miles of stream channel. 
  • The maintenance program includes controlling growth of vegetation, repairing scours, removing deposits in the channels, operating more than 200 floodgates, and removing drift and debris following high water.