Dam Spillway Protection
Existing Dams
When a reservoir’s designed top water level is reached, any additional water entering the reservoir must be allowed to flow downstream. In the majority of cases the water flows down a spillway and enters a natural watercourse. With the apparent increase in extreme rainfall events and with greater downstream developments leading to re-classification of dams, spillways often need to be upgraded to withstand greater discharge volumes. Existing spillways may be re-build, enlarged, or provisions made to allow out-of-channel flow
New Flood Storage Dams
Flood storage dams are built at the downstream end of proposed flood storage areas, upstream of the area to be protected. During a flood event the flow of water through a control structure within the dam is restricted, causing floodwater to build up on the land designated as the flood storage area. If the design flood event is exceeded the dam will overtop. To prevent damage to the dam a spillway is usually incorporated into the downstream slope of the embankment. This spillway channel requires erosion protection. Hesselberg Hydro has worked with consulting engineers and dam owners to create cost-effective and aesthetically acceptable solutions to provide erosion protection to spillways.
Please click on the links below to review recent projects:
- OSA for Spillway Channels
- OSA for out-of-channel flow
- OSA for Flood Storage Dam Spillways
- Grout to strengthen gabion Stilling Basin
