Keswick, Storm Desmond (local case study)

Setting, hydrology and vulnerability

Market town in Lake District National Park, Confluence of River Greta and Derwent, History of flooding with major events in 2005/2009

Causes of flooding

Record breaking rainfall (405mm in 48 hours at Thirlmere), Saturated steep slopes from November, Thirlmere reservoir was overspilling before storm, Calvert’s bridge caused 3 metre water rise upstream due to flow constriction

Short term impacts (social, economic and envriomental)

Social - 515 properties flooded, flood warnings/evacuation. Economic - 13% tourism businesses closed immediately, Co-op closed for months. Environmental - Flood Waters contaminated with sewage/oils/chemicals, Destruction of FItz park footbridge

Long term impacts (social, economic, envriomental)

Social - Some displaced for 2 years, psychological trauma. Economic - Recov oery cost £500 million for Cummbria, damaged public perception. Environmental - Erosion at Lydia’s cottages destroyed gardens/outhouses

Immediate responses

EA issued severe flood warnings and provided sandbags and closed floodgates, EMergency works removed 25,000 tonnes of gravel to restore channel capacity, Control centre form emergency services as Keswick town hall

Existing defences (and failure)

£6.1 million scheme (reinforced concrete walls, floodgates in place. Built for 1-100 years event but overcome by Desmond. 1.3% AEP vs 0.5%

Long term responses

Uk government provided £150 million to support recovery (£5,000 to household to improve resilience), Reviews to modify Thirlmere Reservoir to release water before an event, Soft Natural Flood Management opportunities like ‘leaky dams’, Keswick Flood Action Group worked with EA to improve plans (critical of speed of improvements)

Evaluation of responses

Defence scheme failed, Tension between biodiversity legislation and need for aggressive flood management (gravel removal), Hard engineering alone isn’t enough (need NFM)

Keswick Flood Action Group

Community led organisation to represent resident and pressure authorities. Volunteers monitored river levels and used social media to warn vulnerable households before storm. Distributed sandbags and assisted emergency services by identifying high risk streets. Supported residents with insurance claims and pressure authorities for improved defences