Braithwaite Retaining Wall
Overview
The explosive power of the Coledale Beck in Storm Desmond caused extensive flooding in Braithwaite, damaging properties, closing the A66 and destroying the retaining wall supporting the B5292 Whinlatter Pass Road.
Coledale Beck is a main river within the Lake District National Park (UNESCO World Heritage Site), SSSI, so permissions were required from National Park, Lead Local Flood Authority, Natural England and EA. Other significant stakeholders consulted were Derwent Parish Council, landowners surrounding the site, Forestry England, National Trust and businesses cut-off from access to Braithwaite – hotel, campsites and Leisure Company.
The design by Cumbrian based RG Parkins Consulting Engineers and Hydrologists with PBA Ecology produced a design that was aesthetically pleasing and responded to the hydrology and ecology of the beck.
The Works
The works retain the B5292 northwest of Braithwaite. The remnants of the wall were removed. EWCE excavated into bedrock and the failed structure was replaced with a mass concrete gravity wall, faced with local stone.
Sections of the retaining wall were constructed by isolating each section using a combination of and bags and flume pipes. Working with subcontractor, Sykes Pumps, a multitude of river controlling mechanisms were installed, with standby pumps to divert flows away from the construction area. As sections dried the concrete elements were constructed and stone facing attached.
The road was opened on time, delivered safely and without environmental incident. Closure was minimised and works undertaken with minimal disruption to tourism.
Key Challenges
Environmental controls were implemented as wet concrete operations were adjacent to the beck. EWCE would have preferred to commence as originally scheduled in summer, however the tourist industry dictated that the works occurred autumn/winter. Fortunately, water levels were unseasonably low, but continual monitoring was undertaken, suspending work on occasions.
The community was concerned about the effects of road closure on business and interested in the aesthetics of the new structure, if it could resist the violent floods of Coledale Beck, and whether the works would exacerbate/ameliorate the risk of flooding to properties in the village.
Added Value
Community engagement was key to the success of the works. Newsletters, leaflet drops and door-knocks were undertaken with the nature of the works, road closure, diversion, and re-opening, described. The Old Methodist Chapel that houses a community centre and Orthodox Church was hired for site meetings. On completion, a donation was made as contribution to its maintenance.
Villagers commented favourably, pleased with the natural appearance of the wall, use of local subcontractors and attitude of the workforce. Father John described EWCE as “10 out of 10″.