Call us on 01352 700045
or email info@weetwood.net
Vaughan Trading Estate 1 Vaughan Trading Estate 2 Vaughan Trading Estate 3 Vaughan Trading Estate 4

Project: Vaughan Trading Estate, Tipton
Type: Residential Development

Scope

Weetwood was instructed to undertake a Flood Risk Assessment (FRA) in support of the allocation of the Vaughan Trading Estate, Tipton for housing under the Sandwell Allocations and Delivery Development Planning Document (SAD DPD).

Although no masterplan for the site was available, as part of the SAD DPD, Sandwell Council had stipulated an indicative number of dwellings of 349 to be provided across the site. However, it was envisaged that this area would be capable of accommodating significantly more than this number and for the purposes of the FRA it was assumed that the site could deliver up to 650 units.

The Environment Agency Flood Map indicated that the central section of the site was located within the Flood Zones 2 and 3 due to Groveland Brook, a culverted watercourse that flows through the centre of the site.

What We Did

In determining flood outlines for its flood map, the Environment Agency generally assumes that culverted watercourses are only able to accommodate a 1 in 2 year event, with excess flows conveyed overland.

Weetwood investigated the validity of this assumption by determining the true capacity of the culverted reach of Groveland Brook by developing a 1D-2D (ESTRY-TUFLOW) hydraulic model of the watercourse based on a watercourse survey.

Given that the watercourse is culverted for much of its reach and is fed by a number of surface water sewer outfalls serving an extensively developed catchment the 'direct rainfall method' was utilised in order to enable a range of rainfall events to be simulated. This enabled the risk of of pluvial flooding to be assessed as well as the risk of fluvial flooding from Groveland Brook.

The model outputs indicated that during all modelled events the culverted section of Groveland Brook became surcharged, with floodwaters subsequently flowing across the site and ponding in low lying areas.

A mitigation strategy was subsequently developed in order to mitigate the risk of flooding from this source. This included raising finished floor levels and the provision of storage facilities to accommodate the volume of floodwater expected on site without increasing flood risk elsewhere.

Weetwood subsequently prepared a flood risk assessment outlining the findings and also assessing the risk of flooding from other sources including Dudley Port Brook, Birmingham Canal, Dudley Canal, groundwater and surface water.

Outcome and Value Delivered

The flood risk assessment demonstrated that the site could be redeveloped for the greater number of residential dwellings anticipated, thereby maximising the development potential of the site.

Details of the modelling undertaken by Weetwood, and the FRA were subsequently submitted to and accepted by the Environment Agency, and as a result the site has been allocated for residential development within the SAD DPD.