Concrete Outfall Replacement in Bishops Sutton

The Environment Agency has used the Rootlok Vegetated Wall System to replace a concrete wall as part of an outfall decommissioning scheme in Bishops Sutton, installing a green solution.

In Bishops Sutton lay a redundant outfall and chamber constructed over 30 years ago that needed to be decommissioned. The outfall was installed to discharge borehole water from a nearby village into the River Itchen during periods of drought, however it was never used.

The EA planned to infill the concrete channel leading to the stream and block the opening. Early designs called for a 3.75m long x 1.2m high reinforced concrete wing wall, extending from the outfall pipe to form a hard-edged stream bank system. However this design was over-engineered, time consuming and expensive, thus GeoGrow Ltd was invited to site to offer a more environmentally friendly solution using the Rootlok Vegetated Wall System. Rootlok is a proven, cost-effective alternative to concrete and is fast and easy to install.

The Rootlok System was approved for use and our design for a tie-back wall was installed. GeoGrow supplied bags suitable for a water application and ready to establish vegetation immediately, thus requiring little effort to obtain a sustainable green finish. To install the new wall, the existing pipework and channel linings were removed and filled in and the stream bank regraded. The work was completed within 7 days, with the Rootlok wall taking only 1 day to be installed.

Rootlok will provide a permanent long-term erosion protection system to the newly formed bank. The system will create a natural finish once vegetated that offers real bio-diversity gains and adds to the local eco-system. On top of the significant environmental benefits, choosing Rootlok allowed the Environment Agency to save thousands of pounds and reduce the time needed to complete the works.

Project:

Outfall Replacement, Bishops Sutton

Client:

Environment Agency

Consultant:

Black & Veatch

Contractor:

Environment Agency Operations Field Team

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