Poplar Farm, Grantham
This is a large residential development on the edge of Grantham creating up to 1,800 new homes on a greenfield site. An earlier phase of the scheme had created a large attenuation basin linked to a small stream passing through the development but to lower design standards than now required. The ground conditions were generally clayey with no feasible prospect of using infiltration. The site topography posed another constraint with some areas of steep hillside limiting where attenuation features could be created without requiring greater space to tie into the surrounding landscape due to the side-slope.
The solution comprised a series of five additional basins linked to the stream as the main flow-path for the attenuated flows. These intercept flows from different parts of the scheme and control the onward flow rates prior to the main attenuation lagoon. The new basins are a mix of ponds and dry basins and are situated in corridors of open space, contributing to the landscape and habitat content of the development. The local wildlife was quick to take advantage of the new ponds with waterfowl and insects moving in soon after completion.