Chesil Beach Flood Defences (Chiswell)
Chiswell, Portland, Dorset, UK · Ongoing management; significant repair works in 2014 following winter storms (original defences from 1958 onwards).
The judgement call
Account-gated at launchThe Shoreline Management Plan for this unit (Chiswell to Chesil Beach 6A02) adopts a "hold the line" approach, meaning defences are maintained or replaced along approximately the current alignment. - Emergency repair works after the 2013-2014 winter storms highlighted the vulnerability of the defences and the need for continuous monitoring and rapid response. - The project involves close collaboration between the Environment Agency and local councils. - Regular surveys and data gathering are crucial for informing future beach management and emergency response. - The use of flood alert sirens and community flood plans are integral to the management strategy.
Key engineering challenges
Maintaining the integrity of the shingle beach, which acts as a natural flood defence, against severe wave action and storm surges. - Repairing and refurbishing hard defences (sea wall, Gabion Castle, gabion crest protection mattresses, Monsoon Drain) that protect the low-lying land behind Chesil Beach. - Managing the dynamic nature of Chesil Beach, including shingle replenishment and re-profiling after storm events. - Protecting the community of Chiswell and the road connecting Portland to Weymouth from flooding.
Project facts
- Client / owner
- Environment Agency; Weymouth & Portland Borough Council (now Dorset Council)
- Lead contractor
- —
- Lead designers
- —
- Project type
- upgrade | refurbishment | maintenance
- Scale
- Protects approximately 110 properties in Chiswell; 150,000 cubic metres of shingle lost from the beach during 2013-2014 winter storms.
- Disciplines
- civil; coastal engineering; hydraulic
- Standards & frameworks
- Shoreline Management Plan (SMP16, unit 6A02); relevant UK flood defence standards.
Sources: "Chiswell to Chesil Beach 6A02", Environment Agency, https://environment.data.gov.uk/shoreline-planning/unit/SMP16/6A02 - "STORMS AND COASTAL DEFENCES AT CHISWELL", Dorset Coast Forum, 2021, https://www.dorsetcoast.com/wp-content/uploads/2023/09/4573-Dorset-Coast-Forum-Chiswell-Sea-Defence-Booklet-Updates_2021_V3_FINAL.pdf - "Chesil Beach Flood Defences", FloodList, 2014, https://floodlist.com/europe/united-kingdom/chesil-beach-flood-defences - "Coast protection in Weymouth and Portland", Dorset Council, https://www.dorsetcouncil.gov.uk/w/coast-protection-in-weymouth-and-portland