An attenuation reservoir is a show pond created to take a fast runoff, store it and to let the water go into the watercourse at a much reduced rate!
On this occasion Jon Allerton was asked to provide a floating pump arrangement to remove water from a lake in Nottinghamshire after heavy rainfall. Cost was a major consideration and only a small amount of water would be permitted to enter a ditch which was, in effect, above the water level in the pond.
To do this, a frame was constructed to hold the pump so it was near the surface, not near the muddy bottom. The frame had to hold the pump and the floats. The problem was to get the frame and floats balanced so that it would keep the pump vertical, to save undue pressure on its internal bearings.
The arrangement, or raft, had also to bear the weight of the cable and the flexible 50mm pipeline, from the centre to the edge of the lake. Another float was added part way along the pipe line.
On shore, a control panel was needed to allow the pumping operation to be time controlled. This would allow a limited amount of water to be discharged and for it to be spread out over 24 hours. Several years later and our customer is well pleased.
Another job done!