UNION — The Stillwater River north of the Englewood Dam reached 27.31 feet Tuesday causing Martindale Road to flood in the City of Union, which remained closed to through traffic as of Wednesday afternoon. Flood stage is considered 58 feet.
In addition to the Miami Conservancy District’s dams and levees, floodgates are an important part of the flood protection system, too. Closing floodgates is one of the first actions taken by MCD field staff during a high-water event.
Cities have storm sewer pipes running through MCD levees. These pipes drain city streets to the river. Floodgates are built at the end of storm sewers. During high water, floodgates prevent river water from backing through the sewer into the cities. MCD maintains and operates 185 floodgates of the estimated 237 total floodgates within the system, and inspects each of its gates annually. The remaining floodgates are operated by the cities of Dayton, Piqua and Hamilton.
Sluice gates are the most common type in the MCD system. Typically, they are mounted in concrete gate chambers or manholes. They remain open most of the time and are temporarily closed during high water events. They range in size from 12 inches to 138 inches wide. Most are square, but a few are round or rectangular. Staff operates them either with a crank or with an electric drill.
Englewood Dam is on the Stillwater River. It is 4,716 feet long and 110.5 feet high. The drainage area above the dam is 651 square miles. It would take 28 days to empty the retarding basin after a maximum high-water event. Englewood Dam can store 101.68 billion gallons of floodwater.
The Miami Conservancy District’s Main District is responsible for an integrated flood protection system that significantly reduces flood risk from the Great Miami River in cities from Piqua to Hamilton. MCD developed and built the system of five dry dams, along with 55 miles of levee; and preserved thousands of acres of floodplain. Together, the dams have stored floodwaters more than 1,900 times since construction was completed in 1922. MCD has reinvested in the dams and levees over the years to ensure the system’s integrity for future generations.
MCD’s flood protection is known around the U.S. and the world. Officials from other states and countries have visited to learn more about it. Today, MCD has more than 20 people dedicated to the daily operations, maintenance and inspection of the system.