Flood risk assessment at Luneside West, Lancaster

Client: Countryside Properties

Entec was commissioned by Countryside Properties to undertake a flood risk assessment in support of an outline planning application for the proposed re-development of the former Lune Mills industrial site, known as Luneside West, on the south bank of the river Lune. The proposal was for a mixed-use development comprising residential, commercial and retail land uses. The FRA included an initial study to consider all possible sources of flooding and then further assessed the risk posed by each, also considering data made available by the EA regarding the proposed flood alleviation scheme.

The assessment was undertaken in close consultation with the EA, their agents undertaking the design of the scheme, Lancaster City Council, United Utilities and the client’s design team. Entec also consulted the local fire brigade to discuss emergency access and egress issues, a requirement of Planning Policy Guidance Note 25 (PPG 25), Development and Flood Risk.

The flood risk assessment concluded that there were residual risks associated with surface water run-off, generated from within the development during severe storm events, not being able to discharge off the site during tide-locked conditions and also with the operation of two demountable barriers / gates in the existing flood defences. However, it was concluded that the development as proposed could be designed to satisfactorily mitigate the various flood risks and an Outline Application was submitted on this basis.

Strategic flood risk assessment

Client: Pendle Borough Council

Pendle Borough Council commissioned Entec to undertake a strategic flood Risk Assessment (SFRA) alongside a Sustainability Appraisal  to inform the council’s emerging Local Development Framework (LDF), supporting decisions on future development and regeneration in the borough with respect to local flood risk issues. The SFRA was undertaken in line with the guidance set out in PPS25 Development and Flood Risk and tailored to the specific flooding and development issues facing Pendle.

Particular areas in Pendle Borough have a history of flooding. The Environment Agency flood zones and hydraulic models were used to assess the flood risks posed by the main rivers and nine watercourses were identified as Critical Ordinary, having the potential to pose significant flood risks to people and property. Seven of these watercourses are culverted for long reaches under urban areas which pose an additional risk of blocking or constricting flow causing water to surcharge and flow overland. Other sources of flooding were also considered, including sewer flooding, overland flow, runoff control and groundwater. The SFRA provided a collated source of all flood risk information currently available. This included consideration of planning policy as well as catchment flood management plans and relevant flood risk strategies. During the development of the SFRA, all digital information was compiled into a GIS and detailed graphical outputs were included in the final report.

The SFRA then focussed on potential flood risks to specific brownfield areas in the Brierfield, Nelson and Colne urban corridor identified for potential regeneration and development. Recommendations were provided on flood risks issues specific to these areas to inform the planning and design process, and to inform more detailed Flood Risk Assessments (FRAs) of any sites selected for redevelopment.