Wrangle sea bank raising project, Lincolnshire

This article provides a short overview of the Wrangle Sea Banks raising project, undertaken by Witham Fourth Internal Drainage Board on Behalf of the Environment Agency to protect wider Lincolnshire from coastal flooding.

The main Issues:

Many East Coast catchments in the UK were reclaimed from peat and salt marshes over the last 400 years and at Wrangle, there is only one single sea bank built in 1810, providing the sole defence against the North Sea.

Climate change since 1810 has resulted in several breaches of the banks, the most significant in terms of loss of life was in 1953, but again in 1978 and most recently in 2013.  This risk is further exacerbated by the fact that the East Coast is sinking by an estimated rate 0.4 to 0.7mm per year.

Coastal catchments along the East Coast of Lincolnshire tend to be rural and as such, do not have the businesses and domestic properties required to trigger and compete for flood defence grant funding, making the affordability of large scale projects difficult.  As a result, no single Risk Management Authority (RMA) would be able to deliver this project.

The Sea Banks around The Wash are maintained by the Environment Agency (EA) and a survey of the Banks in 2012 had identified a 5.8km length of bank at Wrangle in Lincolnshire as being the most vulnerable.  Similar EA managed projects on the Humber Banks suggested that the COST/BENEFIT ratio produced by improving the defences at this rural location, would not result in sufficient funding.

Harnessing the stakeholders:

A fresh approach was required that harnessed all of the stakeholders that would benefit from the improved standard of protection that a higher sea defence would offer.  The stakeholders identified were:

• The EA, who maintain the defences and wanted them to be improved
• Witham Fourth District IDB (W4IDB), the Drainage Board that manages water levels and pumping stations behind the sea banks
• Landowners, who farm behind the sea banks
• The Local Enterprise Partnership (LEP) who were keen to promote economic growth, facilitated by a higher standards of flood protection
• Natural England, who are responsible for maintaining the SSSI and UNESCO RAMSAR status of the adjacent saltmarsh in The Wash
• Cattle owners and herdsmen, who graze the saltmarsh and need access across the bank to organic pastures behind the banks at high tide
• The public who regularly walk along the sea bank

The EA approached W4IDB to lead a project which would utilise their close relationship with landowners and other partners and the ability to procure a local contractor to deliver the project.  This process began in 2014 and preliminary discussions resulted in an outline scheme being promoted for funding applications.

The Objectives of the scheme:

The original objectives of the scheme were to re-instate the bank to its original design standard of 6.5 metres and to create at least 5 hectares of improved habitat by taking land out of agricultural production.

A competitive Official Journal of the European Union tender process would be used to ensure the project costs were minimised.  DEFRA funding of £1.5M was sought to achieve this and landowners were approached to give up to 40 linear metres of land behind the sea banks, to provide the spoil for construction.  The cost of carting spoil to site was uneconomic and the value of this in-kind contribution is £200K  

Through the LEP, an additional £0.5M was targeted under European Regional Development Fund funding to add an additional 0.5 metres to the banks.  The LEP’s economic growth agenda necessitated a much higher standard of protection, to give agri-businesses the confidence to invest for the long term in the area.  Due to the UK’s EU exit decision in 2016, this funding was only available for a limited time.

The intention was that the project would therefore be completed with 100% grant funding as W4IDB did not have any funds available, but the significant leadership and project management time required would be provided at no cost.

Project Outcomes

The bank construction works began in April 2018 and were completed on 28 September, and subject to the establishment of grass on the banks over the next 12 months, the new bank is now providing increased levels of protection for 3,500 Hectares of prime agricultural land and 460 properties.

Over 5 hectares of habitat has been created and the new bank will form part of the UK’s National Coastal Path once this is established by 2020.

Conclusion and recommendations

The true partnership nature of this project demonstrates that a scheme can be delivered within the funding constraints imposed by the UK government and this establishes an important precedent for raising the height of other sea banks along the East Coast of England.

Author: Peter Bateson BA FCCA MBA, Chief Executive, Witham Fourth District IDB, UK