A forebay is an artificial basin or pool of water situated upstream of a larger water body such as a reservoir, lake, or hydroelectric facility. It serves a variety of functions, including flow regulation, sediment capture, hydraulic buffering, and ecological enhancement. [1]
Forebays act as holding basins during periods of intense rainfall or snowmelt. They slow the movement of water to prevent sudden surges into downstream reservoirs or urban drainage systems, thereby mitigating flood risk and protecting infrastructure. [2]
Forebays reduce water velocity, allowing sediment and debris to settle out before water enters a reservoir or treatment plant. This reduces the need for dredging and prolongs the life and effectiveness of downstream systems. [3]
In hydroelectric installations, a forebay serves as a regulating reservoir, maintaining a stable flow of water to turbines. This ensures optimal performance and protects machinery from water hammer effects caused by abrupt changes in pressure. [4]
In addition to technical purposes, forebays may support biodiversity by creating aquatic habitats. They can also be developed for recreational uses such as fishing, birdwatching, and canoeing, especially when integrated into urban green infrastructure projects. [5]
Design specifications for a forebay depend on hydrological data, sediment load, and operational purpose. Essential components include:
Maintenance is crucial for sustained operation. Periodic dredging is often required to remove accumulated silt. [6]