Part of a 17-year Beach Management Scheme to protect the coastal frontages of Poole and Bournemouth
7th October 2020
All 53 timber groynes along Bournemouth’s beaches are being renewed, in multiple short phases, as part of the Poole Bay Beach Management Scheme 2015-2032
The fourth short phase starts in October, with a two-year, £1.9 million programme to renew eight timber groynes from the boundary of Poole/Bournemouth to the eastern side of Durley Chine.
The first set of groynes to be renewed stretch from the boundary to Middle Chine. Five groynes will be deconstructed, to be replaced by four, more evenly spaced ones.
Our contractors, Suttle Projects Ltd, will be on site from Monday to Saturday, during normal site working hours. They will work with the lowest tides on a rota system, which may mean some work will take place outside daylight hours. We anticipate this first phase of the groyne renewal project will be completed by spring 2021, subject to weather conditions and working arrangements based on latest Covid-19 guidance.
Work on the remaining four groynes is scheduled to start in autumn 2021, completing in spring 2022.
Our photo shows the four timber groynes running from Alum Chine, west towards the Bournemouth / Poole boundary.
These will be replaced by three new groynes spaced slightly differently (see the plan above).
The fourth new groyne deconstruction/replacement will be at Middle Chine, eastwards of this photo.
The new groynes
Each new groyne will be constructed using a mix of new tropical hardwood timber and recycled tropical hardwood planking, from previously deconstructed timber groynes
Hardwoods used will be Greenheart – a pale yellow to dark olive green wood from Guyana, South America, and Ekki – a dark red / deep chocolate-brown wood from West Africa and the Congo. These timbers have been selected for their strength, durability and resistance to marine life which can destroy wood by boring into and eating it.
Visitor access & safety
Access along the promenade will be maintained to allow visitors to pass the works, but areas of the beach will be restricted for safety reasons.
Sand becomes very unstable when it is excavated around groynes; for this reason, we ask visitors not to pass the construction zone along the water’s edge, even at low tide. Dogs should be kept on a lead.
Once work is finished, restrictions will remain in place until the sand dries out and becomes more compact and stable underfoot. Small ‘cliffs’ may appear where the sand meets the sea, but wave action will soon sort the sand into a natural beach profile.
All the groyne renewal works will be carried out in accordance with the Marine Management Organisation licence and planning consent. Additionally, new tropical hardwood timber used for this project is certified sustainable by the Forestry Stewardship Council (FSC).
Existing groynes will also be carefully deconstructed to ensure that all suitable materials can be recovered and recycled or re-used in future groyne renewal projects.
Groynes – their role in coast protection
Strategically placed timber groynes slow down the natural process of ‘sediment transport’ of beach material within Poole Bay (primarily from west to east). Piling and planking deep into the beach, to the first solid layer of rock, helps retain the sand within a groyne field. Timber groynes are renewed approximately once every 25 years.
In combination with periodic beach re-nourishment (topping up the beach levels) groynes help protect our promenade and seawalls from undermining, and the cliffs from erosion by wave action. The next beach re-nourishment project is planned for early 2021.
Previous phases of timber groyne renewal:
- Winter 2017/18 and 2018/19 – 12 groynes at Southbourne
- Winter 2016/17 – 8 groynes eastwards from Fisherman’s Walk to Gordon’s Corner
- Winter 2015/16 – 10 groynes from the east of Boscombe Pier to Fisherman’s Walk