Balancing Lake - Engineering

Engineering

At its simplest, a balancing lake can be constructed by creating a dam across a drain or stream at a convenient valley, with a restricted diameter outlet pipe through the dam. Normal flows are carried happily through the pipe, but heavy flows back up and the water behind the dam is choked back. Over the following few days, the level subsides. This is often enough for a small housing development.

More advanced systems are computer controlled such that the entire flow of a river can be diverted into a holding lake, perhaps to reduce the impact of a large scale rain storm in the catchment on communities down river.

For aesthetic and safety reasons, the system can be designed so that there is a permanent lake. A lake with an equivalent area of 1000 by 1000 metres rises by one metre will hold a million cubic metres of water. Typically such a lake would have an outer earth bank of 1 metre, then a leisure path, then a 10 cm inner bank to the steady state level.