Nene Lock Reversals

Where is the project area?

There are currently 7 locks which are reversed on the River Nene. These are: Yarwell, Elton, Warmington, Cotterstock, Wadenhoe, Titchmarsh and Doddington. 

What is lock reversal?

Lock reversal is the practice of manually opening a lock to manage river levels during periods of heavy rainfall, increased flow and high river levels. Our operatives open gates at both ends of the lock so that water can flow through.

Why are we stopping lock reversal?

We are stopping lock reversal to reduce safety risks. There are three key groups which are at risk when a lock is reversed:

• Boaters
• Members of the public
• Operational staff

Using lock reversal to manage water levels creates strong currents and white water in and around locks. The strong currents are hazardous for river users and anyone nearby an open lock, including our staff.

We send out messages to pre-registered river users (River Advice to Boaters) when rivers are in strong stream to advise against navigation. However, there have been incidents where river users have not followed advice and boats have been sunk in reversed locks.

Members of the public and our staff who carry out lock reversal could fall into the locks or have difficulty if water rises quickly. We inform the public about the risks associated with rivers, but we are concerned that someone could drown. 

What is the impact of stopping lock reversal?

We are working to identify ways to manage flood risk without needing to reverse locks. This will have the following benefits:

• There will no longer be a reliance on operators manually operating the locks to manage flood risk. Climate change is increasing the frequency of flood events. Rivers rise more rapidly, leaving less time for our operators to get from our depot to reverse the locks. 
• Opportunities to improve the environment may happen because of the project.  Projects we have completed elsewhere include creating wetlands or restoring historic river channels. These slow the flow of water through communities downstream, to reduce flooding and create valuable habitats for wildlife.  

We have assessed the impact through modelling which has provided details on flood depths and the onset of flooding in the area surrounding the locks.

Stopping this practice will not increase the extent of flooding. However, there may be a change in flood depths and the onset of flooding to some properties and land.

In smaller flood events, flooding may occur earlier near a lock that is no longer being reversed. Water is likely to come out of the channel onto the flood plain more frequently and for longer. River and flood levels may also be higher. In larger flood events, stopping lock reversal will have minimal impact on flood depths, the onset of flooding and extent of flooding.

We will deliver these works in a phased approach. Allowing lock reversal to be stopped on a lock-by-lock basis will gradually reduce the health and safety risks. 

Why is the project needed?

We have used computer software to better understand the impacts and test options for each of the 7 sites. We are looking to improve risk to properties that see a change in flood depths and the speed of flooding. We are discussing these ideas with local landowners, communities and key partners, as well as working with these stakeholders to identify any other possible opportunities.

We are working with landowners to explore opportunities to store flood water on the floodplain as well as looking at working with nature based and traditional hard engineering solutions to reduce flooding. 

What are the project objectives?

The project team have worked together to develop 3 objectives we hope to achieve through this project:

• Health and safety: to ensure the safety of boaters, river users and our operatives who reverse the lock.
• Mitigating potential flooding impacts to properties which result from stopping lock reversal.
• Engagement with the community: ensure that the community and stakeholders are consulted and engaged in all stages of the project. Ensure they understand the project, its benefits, impacts and timescales.

Funding

The source of funding will depend on the mitigation options identified. We will work with other partners such as Natural England, Wildlife Trust and local landowners to explore these options.

Who is involved?

Many of our teams are working collaboratively to deliver the RNLSI project. This includes;

• operational field staff who you will see operating the locks
• asset performance teams
• flood risk management teams
• our waterways team who manage navigation and boating on the River Nene
• Major Projects and Programme Delivery Team.

We are working with JBA Consulting and Jackson Civil Engineering who will be supporting design of any mitigation ideas. This will ensure technical designs are practical to build and operate.

Local landowners and communities are key to the success of this project. We will continue to engage with them.

How are we engaging with our stakeholders?

We have already begun meeting with landowners who are likely to be impacted by the change.

We have been in contact with the relevant Parish Councils and plan to meet with them in the near future to further discuss the project.

Other stakeholder groups have been identified and we will be making contact with these in due course.

We will be holding drop in events for the communities to give us their views. We will provide dates once they are confirmed.