The Newt Ditch Marlow Flood Alleviation Scheme

The key elements of the scheme are:

We plan to:

• remove and divert existing utility services currently within the existing 450mm pipe, and clean and repair the pipe as required
• construct a new brick manhole at the Dedmere Road and Quarrydale Drive junction, where this will connect to the new open channel section.

We plan to:

• replace the existing pipework with a new 1m wide by 1.2m deep open concrete channel over a length of approximately 85m; there will be headwalls at either end
• provide a new, permeable, riverside footpath including low level lighting

We plan to:

• retain the existing 750mm diameter pipework and cleaned and repair it if required
• relay the existing footpath and provide new low level lighting

We plan to:

• replace the existing pipework with a new open channel to be formed on the line of the of the existing Newt Ditch, for a length of approximately 225m
• provide a new permeable access path including lighting

We plan to:

• regrade approximately 100m of the Newt Ditch
• modify the existing siphon arrangement to improve flow

There are multiple benefits of the proposed project, including:

• a reduction in flood damages (£61.4 million) to properties and infrastructure when flooding occurs
• reduction in the risk of culvert blockage through creating open channels, as blockages in open channels will be easier to identify and simpler to remove
• additional open channel habitat through extension of the open section of the Newt Ditch
• health benefits of reduced flood risk
• reduced costs to the emergency services in responding to flood events
• reduced costs of evacuation of residents as a result of flood events
• reduced risk to life from flooding

In April 2024 we supported the principle of alleviating flood risk to nearby properties

We're seeking permission to construct the Proposed Development for elements of the wider Newt Ditch, Marlow FAS that do not constitute permitted development.

We've submitted a planning application and it's now open for consultation.

As part of this, we are currently undergoing a formal notification process for the Proposed Development. Letters will be sent to those which Buckinghamshire Council are aware have land or property which may be affected by the scheme.

You can view or comment on the scheme planning documents using the planning reference number 24/07725/R9FUL.

You'll be able to comment for 21 days from 4 December 2024 (the date of notification).

If you need help, email: [email protected]

We can translate the information or send it to you in different formats if you need it.

We have recently carried out vegetation clearance alongside the Newt Ditch to facilitate an updated topographical survey that will inform the detailed design.

We've reviewed CCTV of the existing drainage network (under Dedmere Road, Quarrydale Drive and the footpath leading to the A404).

This shows the existing culvert to be blocked in several locations.

We've produced a detailed FRA which shows the scheme to have a negligible impact on flood risk downstream.

We've also considered the environmental impacts and we'll implement a comprehensive environmental mitigation plan (where required).

Our Buckinghamshire Highways team are monitoring Fieldhouse Lane and their advice is to respond using the Bucks emergency number:

• inside working hours; 01296 382416
• outside working hours; 01296 486630

You can also call the National Flood Forum (01296 403055) for help with:

• insurance
• setting up flood groups
• advice on individual Property Flood Resilience measures

If you rent a property

Inform your landlord or the housing association if your home needs repairs due to flooding.

If you own your property

You should investigate how to make your home more resilient against flooding.

View our flooding resilience website.

If you've already suffered damage from flooding, you can ask your home insurer about the 'Build Back Better’ scheme.

If your insurance includes this scheme, the insurer should work with you to assess if additional flood resilience or resistance measures could benefit your home.

The scheme covers the cost of installing measures up to the value of £10,000 over and above work to repair damage and loss caused by a flood.

We've prioritised securing funding for the next stage of the project and our business case has been approved by the Environment Agency.

We have also been progressing with the detailed design for the scheme, and we have been undertaking a range of surveys to help us improve our understanding of the scheme area.

These surveys include carrying out utility surveys in the project area and undertaking an ecological walkover survey. There are also ground investigation surveys planned in the near future.

To inform the FRA, we have also recently conducted topographical surveys for the River Thames towards Bourne End. The FRA will help us to understand the downstream flood risk and any potential impacts of the scheme.

Buckinghamshire Highways are continuing to monitor the situation and their advice is to respond using the Bucks emergency number:

inside working hours: 01296 382416

outside working hours: 01296 486630

Call the National Flood Forum (01296 403055) for help with:

insurance

setting up flood groups

advice on individual Property Flood Resilience measures

Through the detailed design we are working to ensure that as few trees as possible are affected by the scheme. The design development work also includes assessing the extent and location of possible screening and re-planting of trees.

Where there’s a requirement to re-plant, Jacobs will adhere to our tree planting requirements and where possible will minimise tree removal.

We will have more information on re-planting, screening and impacted trees in our planning application once we have finished the detailed design works. These are due to be submitted in the first half of 2024.

We’re concerned around the maintenance of the culvert and proposed open channel on the land which is not registered. Currently, there are no funds for the maintenance of this however we’re discussing this internally.

For the parts which are under the responsibility of the individual owners (on the banks), the current assumption is that it would continue to be their responsibility to maintain the culvert and proposed open ditch.

We will have a clearer understanding of the situation as the project develops.

View more about Riparian landowners responsibilities for maintenance of Ordinary Watercourses.

At this current stage, we are developing the detailed design of the project. This means we are not in a position to know the details of the construction arrangements.

We are due to submit our planning application in the first half of 2024 and following this we will have more information available on the construction of the project.

If the planning application is successful, it is intended that construction will start in 2025.

We will contact everyone affected to give sufficient notice.

We are still investigating the downstream flood risk and are undertaking extensive surveys and extra modelling to develop the FRA.

This includes recent topographic surveys towards Bourne End.

We will be able to provide feedback of our findings to residents when complete, expected early 2024.

The planning requirement is that there is no increase to downstream flood risk because of the project, this extra work is to provide the evidence base to support this.

The FRA will be included in the planning application – which will be publicly available – expected to be submitted first half of 2024.

The project team have continued to work hard in developing a viable flood alleviation scheme for East Marlow.

Over the last 6 months our work has focused on:

• the completion of the A404 culvert clearance works and survey work of the oil separator, pipes and manholes
• the completion of topographical surveys of extended project area east of the A404
• updates to the hydraulic modelling
• the production of an updated economic appraisal
• the development of outline design drawings
• carrying out of additional environment surveys, including ground-based bat roost assessment, bat activity surveys, badger walkover survey, and a preliminary ecological appraisal

Due to the current economic climate and the increasing costs of materials and labour, we carried out an updated economic appraisal of the scheme's scope.

The appraisal found that we would not be able to secure sufficient government funding to continue with the original scope.

We've now developed a revised scheme. The cost is significantly lower and gives the project the best opportunity to secure government funding.

The properties that would have benefited from the original scheme will continue to benefit from a reduction in flood risk under the revised scheme, as flood volume levels will be reduced across the area.

Following previous incidents of flooding in and around Fieldhouse Lane, the operations team have supported the local community impacted by the flooding. The team have helped clear out the soakaways in the area and reviewing opportunities for additional improvements, including installing a new soakaway close to Fieldhouse Lane.

In March 2023 we asked all those who had been impacted by the recent flooding event to complete a survey so that we could understand what happened and how residents were affected, to help us finalise our plans to reduce flood risk in the area. We received responses from various residents and will consider this feedback when developing the scheme.

We’ve been working with the Environment Agency (EA) to assess the flood risk of flows from the Newt Ditch moving east beyond the A404, downstream of the immediate project works area.

It was agreed with the EA to carry out a detailed flood risk modelling assessment to improve our understanding of how the water moves from the east of the A404 to the River Thames. Topographical surveys over 3km, stretching to the River Thames at Bourne End were carried out to inform the modelling work. This model outputs indicated that the downstream impact of the proposed scheme downstream of the A404 would be negligible.