Flood Risk Assessment & SuDS Report: prepared to support a planning application for the construction of a four-storey office building, including associated parking and landscaping.

Planning Consultants: SM Planning

Four Storey Office Development – Haringey Borough Council

Nimbus Engineering Consultants were commissioned by Herts Heritage Building and Roofing Ltd to provide a Flood Risk Assessment and SuDS Report to support a planning application for the redevelopment of an existing site. The proposed development comprises the construction of a four-storey commercial office building, with associated parking and landscaping, as required by Haringey Borough Council.

Our Flood Risk Assessment and SuDS Report confirmed that there are no significant flood risk issues or concerns at the site. In addition, our proposed SuDS solution reduces surface water runoff by 99% compared to the existing site’s Qbar (urban) rate.

Areas of sedum roofing have been proposed where feasible, along with rainwater harvesting, ensuring compliance with the SuDS hierarchy. However, infiltration was not considered viable due to the underlying ground conditions.

The proposed car parking areas are designated for heavy vehicle use. As a result, our SuDS design incorporates a bypass separator alongside porous surfacing, underlain by a hydrocarbon-removing geotextile membrane. The remaining surface water runoff is managed via an attenuation tank, with a controlled flow restriction to the existing surface water drainage network in the adjacent street.

The proposed SuDS Report design and surface water drainage strategy was modelled using industry-standard software and FEH data, in accordance with the London Borough of Haringey’s requirements.

Furthermore, we carried out the necessary capacity checks with Thames Water to ensure full compliance with the London Plan.

Result

Planning application approved with a successful outcome and satisfied client.