Sandwich Flood Alleviation and Spillway Scheme

Rock Mattress tie in detail at hydraulic jump zone with VMax C350VMax C350 installed for spillway protectionVMax C350 with excellent grass establishment on spillway slopesRock Mattress at spillway toe
<
>
Rock Mattress tie in detail at hydraulic jump zone with VMax C350

The £21.7 million flood defence scheme involved works on 16 individual reaches of the river and it reduced the risk of tidal flooding to 488 homes and 94 commercial properties in Sandwich.

Client – Jackson Civil Engineering working on behalf of the Environment Agency.

Salix worked with Halcrow during the early design stage of the £21.7million Sandwich Flood Alleviation Scheme, which involved works on 16 individual reaches of river.

Salix supplied 120,000m2 of VMax C350 Composite Turf Reinforcement Matting (C-TRM) to protect the spillway slopes.

Potential duration of overtopping for the spillway was around 6 hrs, therefore a permanent, high performing reinforced vegetative solution was required.

Vmax C350 met the design brief by running design software looking at discharge, permissible/calculated shear stress, velocities and duration.

Damage to area after tidal surge with no VMax C350 protectionSeptember installation of Vmax C350 on spillwayPre-established Coir Pallets and Rock Roll mattress at base of spillwayNewly installed VMax C350 protecting slope compared to opposite bank with no protectionSpillway January 2014 four months post installation
<
>
Newly installed VMax C350 protecting slope compared to opposite bank with no protection

Details

Name: Sandwich Flood Alleviation Scheme
Client: Jackson Civil Engineering and Environment Agency
Location: Sandwich
Category: Spillways & Flood Banks

Case Study