Lower Witham Flood Resilience Project

Overview

The Lower River Witham catchment is a large area of fenland between Lincoln and Boston. With land levels ranging from only 1 to 4m above sea level, this area would naturally be marshy wetland. A historic legacy of drainage works and embanked watercourses has enabled the highly productive arable land to be farmed and communities have established in the area.

The embanked channels are of significant age now (in excess of 200 years old) and increasing flood risk is testing these structures more than ever before, putting at risk the communities and economy of the area.  

Background

In 1997 the Lower Witham Strategy recommended reinforcement of key embankments whilst allowing some areas to flood, in order to relieve the pressure on the system. Since then some embankments have been reinforced, but repeated high flows have damaged more. Storage options have not been implemented, due to availability of suitable sites and difficulties in meeting HM Treasury rules for funding.

Flooding in 2019 has again highlighted the need for a sustainable long term plan to manage flood risk in the area. 

November 2019 saw record river levels on the Lower Witham and the Barlings Eau due to Lincolnshire receiving more than double its seasonal average rainfall.

This resulted in a breach on the left bank of the Barlings Eau which enabled flood water to flow onto the flood plain through the breach, flooding farmland and the Short Ferry Road. A breach also occurred on the left bank of Timberland Delph flooding farmland and property. These areas of damage have been repaired by an extensive programme of ‘Recovery Works’ during 2020/21 as listed at the bottom of this page. However, to achieve a more resilient catchment we must revisit our strategic approach and seek to implement those recommendations that still offer an improvement to the current status quo.

Above photo: Barlings Eau breach Nov 2019

Above Photo: Timberland Delph breach Nov 2019

The Lower Witham Flood Resilience Project will, building on the last strategy review from 2015, set the direction to achieving a resilient catchment, through an ambitious programme of works to renew critical assets and implement flood plain restoration where beneficial. This project has been granted funding to undertake surveys and project appraisal in 2021 and 2022.

Project Objectives

• Involve and inform stakeholders
• Sustain and maintain critical banks
• Make space for water
• Create a more resilient catchment

Work to date

The project catchment has been divided into compartments. We have gathered our existing data and begun to analyse the current flood risk and potential benefits the project could provide.  However, surveys of the catchment and its watercourses will be required so we can understand how the catchment has changed since the previous surveys which took place in the late 1990’s and early 2000’s. This updated information will inform the next steps of the project and provide evidence for the options to be considered to improve the resilience of the catchment going forward.

The map below shows the extent of the project area and the individual compartments:

What’s next?

This is a long-term project on a large scale and we are still at the early stages, the project is likely to be ongoing for the next 10 to 15 years.

The Environment Agency project team have commissioned consultants Arup to undertake new surveys of the channels and embankments on the Lower Witham and build a state of the art hydraulic model, taking into account the latest thinking on climate change. The surveys are due to begin this summer, with the new modelling delivered during 2022. Arup will also be bringing their expertise in stakeholder engagement to the project, and will prepare a comprehensive plan to ensure that everyone living and working in the area can express their views.

Options

The original 1997 Lower Witham Strategy concluded that to improve the flood resilience of the area, strengthening of critical embankments and allowing water to overtop safely into designated storage areas is the most likely approach to be successful. Unfortunately, funding and land availability meant that the storage options could not be implemented at the time. However, new data, funding sources, and a much greater awareness of challenges (such as carbon emissions and climate change, a decline in the variety of plants and animals, farm payment reforms etc.) may offer new opportunities and options to achieve a resilient catchment. Options to implement the strategic approach will be identified in partnership with stakeholders in the area, in particular land managers and owners, other flood risk management authorities such as the Internal Drainage Boards, Councils and Anglian Water.

Stakeholders and Engagement

From the outset, we plan to provide the opportunity for all stakeholders to express their views on the future plans to manage flood risk in the catchment. We are ensuring that engagement with communities, landowners, businesses and potential partners is a large part of the project brief.

We hope that this project will be the catalyst for a much more collaborative and accessible approach to managing the current and future risks of flooding in this area, including partnership funding of solutions. We welcome the input of all parties who have a stake in the sustainability of this unique landscape.

If you wish to get in touch with us about the project or be kept up to date on the progress of the project please contact us at the following address:

lowerwitham.floodresilience@environment-agency.gov.uk

Regular watercourse maintenance

While the Lower Witham Flood Resilience Project is being developed, the Environment Agency’s operational teams will continue to maintain and manage the flood defence structures (embankments, flood walls, sluices) in the area where resources allow.

These structures all need regular maintenance and each year we deliver a significant programme of works to help ensure they work when they need to. The Environment Agency bids for public funding every year to carry out this maintenance and we use our permissive (discretionary) powers to deliver the works.

Other ordinary watercourses (dykes/streams) are still important to local flood risk, but are likely owned by the landowner who will be responsible for its maintenance and conveyance. For more information on the responsibilities of owning a watercourse please see https://www.gov.uk/guidance/owning-a-watercourse

Maintenance is carried out at varying intervals during the year depending on the watercourse. The typical maintenance activities we carry out are grass cutting, in channel vegetation clearance, removing obstructions, bush and tree management and operating sluice gates and pumping stations. For more information on these please download the accompanying information sheet from the bottom of this page. 

Recovery Work

Contacts

Lower Witham Resilience Project team contact: lowerwitham.floodresilience@environment-agency.gov.uk

If you see any issues with the rivers in the Lower Witham area, which pose an immediate flood risk, this should be reported directly to our 24 hour Freephone incident hotline on 0800 80 70 60.