A flood dam operates as part of a flood control system to protect communities from uncontrolled flood waters. Such dams do not create reservoirs to store water for use in the future, nor do they generate hydroelectric power. They can be installed by government agencies and communities, and are subject to regulation for safety. A flood dam needs to meet building guidelines and regulators can inspect it periodically to confirm it is in good working order.
For flood management, agencies can place flood dams at strategic points in a watershed like large rivers and lakes. These dams control the flow of water through the watershed and in some cases the area behind them may be dry much of the time. Seasonal lakes, streams, and rivers can become a problem in flood conditions, because they quickly overflow and can overwhelm waterways and communities.
In heavy rains, or when runoff from upstream becomes heavier than usual, the flood dam can kick into operation. It retains water and controls its release to slowly allow levels of lakes and rivers to stabilize. In addition to protecting communities from flood waters, this measure also limits topsoil loss and other environmental problems that can occur in severe flooding. When conditions return to normal, the flood control dams can go back into a dormant mode.
The design of a flood dam can vary, depending on the site of installation and recorded flood data from prior years in that area. It typically includes outlets as well as a spillway for emergencies to prevent failure of the dam in a catastrophe. Flood control dams also include equipment to measure flood waters and some provide remote reporting for government agencies that need to be able to monitor flooding and other activities. A number of construction techniques can be used to make a flood dam, depending on the level of stress it needs to be able to endure.
A flood control system can include a number of dams, levees and other safety measures to control and direct water throughout a watershed in the event of severe weather. Flooding is an extremely common form of natural disaster in many regions of the world. The development of adequate flood control systems is critical for economic, environmental, and human health reasons. Funding for flood control programs typically comes from government agencies, although some communities may also raise funds independently for installation of additional measures for their health and safety.