The application site is designated as being at low probability of fluvial flooding (Flood Zone 1) from Main Rivers. Lower Luton Road is designated as being at high probability of fluvial flooding (Flood Zone 3) either side of the anticipated site access, although flood depths are predicted to be very shallow. The proposed lowering of land along the verge for visibility reasons may provide additional flood storage.
Roads and the railway cutting bordering the site may be subject to surface water flood risk during heavy or prolonged rainfall. The proposals will maintain, manage, or reduce any existing surface water flow pathways in line with best practice to ensure that flood risk to off-site areas is not made worse.
A Flood Risk Assessment will support the planning application and a sustainable drainage scheme is being developed to manage the volume and quality of the surface water run-off from the site. The aim of the drainage scheme will be to ensure that water quality and the hydrological and hydrogeological regimes remain unaffected and, where possible are improved. Underlying ground conditions appear to be sufficiently permeable to allow surface water runoff to percolate through the soil beneath the site. No off-site connections to surface water sewer or the River Lea are anticipated.
Rainwater collection and reuse is proposed to reduce the amount of mains water required in the operation of the CHP facility. Rainwater can also be used within the CHP process, for vehicle washing, site cleaning operations, and irrigation of soft landscaping.
Our hydrologist will work with our ecologist and landscape architect to integrate surface water management features within the site landscape and, where appropriate, to provide permanent or seasonal water features that offer a range of biodiversity benefits.
The image below shows the location of proposed attenuation ponds on site.