CURRENT PROJECTSHoles Bay Flood Defences 2018
New flood defence structures for the Creekmoor and Sterte Channels, housing tidal valves to prevent tidal water travelling back up the channels during high tides.
Borough of Poole
26th March 2018
12th June 2018
The Creekmoor Channel
The Sterte Channel
Flood defence structures are to be constructed at the end of the Creekmoor and Sterte Channels where they meet Holes Bay. The structures will house tidal valves which will prevent tidal water travelling back up the channels during high tides. Ground levels around the structures will also be raised using recycled soil to continue the line of flood defences in these areas.
- The works at Creekmoor started early April and were completed, to schedule, on 30th May; a progress report & flood defence design information can be found below.
- The works at Sterte follow the Creekmoor project; materials & equipment were delivered to site on 30th May; the project will take around 9 weeks.
- Working hours are 7.30am – 5.30pm, Monday-Friday, however there may be some working outside of these times for activities that are affected by the tides.
Poole Council has worked with the Environment Agency and Wessex Water to secure funding of some £700,000 to deliver these flood defences. The work will be carried out on behalf of Poole Council by Avon Construction Ltd.
Maintaining access during the works
Public use of the Holes Bay footpath will be maintained throughout the works, through the use of minor diversions or temporary paths.
Some road lane closures around the sites will be necessary to offload machinery and large deliveries. These will be carried out during off-peak hours on specific days and will be advertised on road signs.
Creekmoor channel project completed
The structure across the mouth of the channel is constructed from two rows of sheet piles driven into the seabed and filled with concrete.
The flood defence structure here forms a bridge with foot/cycle way across the channel, an improvement on the previous route that took pedestrians & cyclists via a ‘dog-leg’ close to the busy Upton Bypass.
18.04.18 Piles have been driven into the channel bed and the pipes that will hold the valves have been installed. Once the water is pumped out the defences can be filled with concrete.
18.04.18 Concrete is placed inside the structure and raked flat to ensure uniform coverage with no voids created. It is also important to ensure no concrete seeps out to pollute the channel or Holes Bay.
20.04.18 Waiting for the concrete to harden. Once completed walkers and cyclists will be able to use this structure as a crossing, cutting out the existing ‘dog-leg’ route.
01.05.18 Creating the structures that will support the railings to either side of the new cycleway bridge
01.05.18 The concrete fill is poured slowly, ensuring an even distribution with no air pockets to affect the strength of the structure
03.05.18 The base layer for the new pathway across the channel, allowing pedestrians & cyclists to keep away from the busy road
A ‘fish friendly valve’ is included in the Creekmoor structure to ensure eels are not restricted in their migratory movement through the surface water system from Holes Bay to waterbodies upstream, e.g. Creekmoor & Millfield ponds. There is no evidence to suggest fish or eels use Sterte channel. This is because it has a concrete base and sheet pile walls, as well as a pumping station which restricts any movements upstream.
The structure across the mouth of the channel will be constructed from two rows of sheet piles placed on to the existing concrete base, and filled with concrete.
Why is the work needed?
It has been recognised that parts of Poole are likely to face a higher risk of flooding due to sea level rise in combination with a more frequent occurrence of wet and stormy weather. This project is one of the defence measures identified to help minimise the flood risk.
- Adapting to Climate Change – Advice for Flood and Coastal Erosion Risk Management Authorities, April 2016: www.gov.uk/government/publications/adapting-to-climate-change-for-risk-management-authorities
- UK Climate Projections 2009: ukclimateprojections.metoffice.gov.uk/21684