Coggeshall, Feering and Kelvedon Flood Alleviation Scheme – information page

Overview

Following our public drop-in events with the Coggeshall, Feering and Kelvedon communities in summer 2019, we have continued to work to the final design for the Coggeshall, Feering and Kelvedon flood alleviation scheme, which aims to protect these communities from further flooding.

As part of the design process we have undertaken modelling of the River Blackwater upstream of Coggeshall. The outputs from this have helped to inform and refine the design of the scheme, including the dam, ensuring it will significantly reduce flood risk and benefit the surrounding communities. 

Once the design stage is complete a planning application and supporting Environmental Impact Assessment (EIA) will be submitted to Essex County Council for their consideration and approval following their formal process, which may vary based on the current and future response to Covid-19.

Local residents and parish councils will then be able to make further comment on the plans as part of the formal planning review process.

Further details about the designs have now been added to this web page. These include presentation boards that explain the further progress and improvements made to the scheme.  

There is also a video presentation to support the documentation that explains the scheme and planned phased construction. This is hosted on YouTube: https://www.youtube.com/watch?v=pfULOeddT-c

Coggeshall flooding in 2001

Background

In October 2001 Coggeshall, Feering and Kelvedon suffered from significant flooding. Since then, in May 2012 and February 2014 the villages experienced further flooding. Due to changing weather patterns the villages are expected to experience more frequent, more damaging flooding in the future.

In 2006 we commissioned a study to explore whether a scheme would be viable for the villages. The study demonstrated that the cost-benefit ratio for this area was low, resulting in options being too expensive to fund through our Flood Defence Grant in Aid (FDGiA) money. The study also highlighted the need to complete a hydrological model of Robin’s Brook, a “Main River” under our jurisdiction before considering a future scheme. This work was completed in 2013 allowing us to carry out further investigation.

Out of the 8 options we consulted upon in 2015, the scheme that received the greatest public support was that of providing flood storage within the River Blackwater. However this option could not go forward for several reasons. Firstly the costs were estimated to be in excess of £6 million, with no corresponding funding source available. Secondly it failed to achieve the required levels of flood protection because there is insufficient storage capacity within the Blackwater Valley.

In 2015 we approached Blackwater Aggregates to ask for their support in developing a low impact and sustainable flood alleviation scheme within the Blackwater Valley that could provide the necessary 1 in 100 year flood storage across land under their control. Through our discussions it became apparent that by working together a long-term solution could be found.

The flood alleviation scheme and next steps

The scheme has continued to develop, arriving at a final design which will provide flood protection to the villages of Coggeshall, Feering and Kelvedon through an “on-line” dam and the creation of an extended flood storage area to manage and accommodate flood flows. 

Location of the “on-line” dam and extended flood storage area (see Exhibition Board 16 for a larger version)

There have been some key changes to the design of the scheme in terms of technical detail; however, the overall principles of the scheme and required level of flood protection for the 203 houses (some of which are important heritage assets) and 15 local businesses located within Coggeshall Feering and Kelvedon remain the same:

• We require 3.02 million m3 storage capacity to create a long-term significant improvement to the flood protection for three communities
• The dam location and finished height remains the same (and will avoid upstream impacts)
• The extension to the floodplain provided by the quarrying activity is still a major factor in the scheme’s design, without which the scheme would not be feasible 
• Contributions by Blackwater Aggregates and the commercial viability of the project remain a key part of this partnership delivery
• The processing plant and means of access for HGVs to and from Bradwell Quarry remain the same

What has been changed since the 2019 public drop-in events?

• The extended floodplain has been designed to provide bio-diverse habitats connected to the existing floodplain  
• The shape and profile of the restored side slope across the southern side of the Blackwater valley has been shaped to provide differing side slope angles, sympathetic to the site’s setting and future land uses
• A crossing point will be established over Cuthedge Lane midway between Deeks Cottage and Haywards   
• Dedicated permissive footpaths have been incorporated into the design of the scheme which will provide new links and lines across the site based on agreements with landowners and discussions with the Public Rights of Way Officer
• Additional areas of broad leaf woodland will be created across the site which will connect existing habitats with the flood alleviation scheme
• The dam itself has been made wider at its base following further analysis of the structure and local ground conditions, this has resulted in changes to the dam and realigned section of the river

We have considered the feedback from the public consultation events we held last year, and where possible made changes. Key to any changes is agreement of the local landowners. If the scheme is successful we hope to build on the project and promote further opportunities for ourselves to work with local stakeholder groups to explore other local initiatives which may be incorporated into the scheme through partnership working.

Project funding

This project has received £1 million from central government (via the Environment Agency), and up to £8 million in direct funding contributions through the Blackwater Aggregates partnership.

Blackwater Aggregates’ normal quarrying operations across the site will ultimately support in the delivery of a flood alleviation scheme that would otherwise mean the public purse would need to contribute in excess of a further £25 million.

Project costs in more detail, excluding the cost of aggregate removal:
• Blackwater Aggregates: Over-dig of clay – up to £6 million
• Blackwater Aggregates: Dam construction – up to £1.5 million
• Blackwater Aggregates: Planning process – up to £0.5 million
• Environment Agency: Project delivery - £1 million