CURRENT projects

Timber Groyne renewal programme, winter 2022/23

Renewing 4 timber groynes adjacent to Bournemouth Pier

LEAD AUTHORITY

BCP Council

START DATE

9th October 2022

END DATE

31st March 2023

Poole Bay Timber Groyne renewal 2022/23

Four old groynes willl be replaced by four new ones, more evenly spaced

Project Overview

October – December 2022: East Cliff – 2 old groynes east of the Pier will be replaced with 2 new groynes, more evenly spaced

January – March 2023: West Cliff – 2 old groynes west of the Pier will be replaced with 2 new groynes, more evenly spaced

Deconstructing and reconstructing a timber groyne – how it’s done

Timber used for 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, when available.

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.

FUNKY FACTS ABOUT POOLE BAY GROYNES

A total of 29 piles are sunk for a timber groyne, each pile is 10m long and spaced 2.5m apart. The King pile (out at sea) is 12.5m long. Piles are driven down to the first solid layer of stable substrate/clay. Each groyne is between 5m-7.5m deep and roughly 75m in length. Approximately 225 planks of timber make up a groyne. The top 5 rows are generally constructed using new timber; recycled timber is used for the bottom 12-14 rows.

Visitor access & safety

Access along the promenade, and to beach huts, will be maintained to enable you to pass the works, but areas of the beach are restricted for safety reasons. The sand becomes very unstable when it is excavated around groynes. For this reason, please do not enter or 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.

Environmental considerations

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).

The old groynes will be carefully deconstructed to ensure that all suitable materials can be recovered and recycled or re-used in future coastal projects. 

Groynes – their role in coast protection

Beach material generally moves from west to east in Poole Bay. The strategically placed groynes are renewed approximately once every 25 years and slow down the natural processes. Piling and planking deep into the beach to the first solid layer of substrate/clay helps retain the sand within the groyne field.

In combination with periodic beach renourishment (topping-up the beach levels) the groynes also help protect the seawalls and cliffs from erosion. We last renourished some of the beaches from Poole to Southbourne in early 2021 [details here].

Previous phases of timber groyne renewal:

  • Winter 2021/22 – Year 2 of a two-year renewal project, 4 groynes eastwards from Durley Chine to West Cliff zig zag
  • Winter 2020/21 – Year 1 of a two-year renewal project, 4 groynes eastwards from Poole/Bournemouth boundary to Middle Chine
  • 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