Sustainable Cities™

Cleveleys: Taking steps against flooding

The new flood defence construction at Cleveleys, a seaside town in north-west England, uses a wave of concrete steps and wide pedestrian promenade to hold flood waters at bay, whilst allowing people to meander from the high street to the beach. Private investment initiatives and public engagement groups have joined together in order to share the ownership of the promenade and to manage a diverse array of commercial, leisure and recreational activities for both residents and visitors.

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Cleveleys skulpturelle kystforsvar. venligst udlånt af Wyre Borough Council

Cleveleys is a small seaside town on the north-west coast of England, five miles north of Blackpool. The town is a popular leisure and shopping destination for the surrounding region of Lancashire. Following an assessment of flood risk for the wider region of Wyre, it was deemed that Cleveleys was under the most risk due to the poor condition of its existing defences and the high number of properties concentrated on or immediately behind the defence line. Cleveleys exploited this unique opportunity to entirely renovate its water front, arriving at a scheme which could not only protect against floods, but at the same time enhance the quality of its pedestrian promenade. This vital stretch of public realm has since proved to be a critical element in sustaining the social and economic welfare of the town, connecting shops and cafes to the beach and hosting a diverse variety of leisure events.

The main challenge when designing the new defence construction was how to protect the waterfront from flood waters and storm spray without blocking views from the high street by erecting a high sea-wall. Traditionally, sea-wall defence has often meant separating the shoreline and beach area from the promenade and shopping street with either a high wall or steep embankment. This often leads to a loss in pedestrian contact from one level to the other, and divides the beach and promenade into two separate zones harbouring different or unrelated activities.

Courtesy of Wyre Bourough Council.

The solution at Cleveleys manages to connect the beach and promenade seamlessly via a wave of stairs which lap back and forth from one area of public space to the other. The stairs themselves act as a flood stop by breaking the wave swell and pushing water back to the sea. At the same time, the stairs form a place where people can sit and engage in the activities of both beach and promenade.

Extra defence is provided at the top of the stairs by a raised level in the middle of the promenade and a higher wall to the back of the promenade. Flood modeling and predictions for rising sea-levels and more frequent coastal storms in the future, set the height of this back at 50cm higher than the existing defence wall. In order to reduce the visual impact of this wall, it follows the promenade's varied and snaking form in plan, and is landscaped with plants which can withstand the harsh climatic conditions.

The promenade lives up to its role as a life-line for both the social and commercial success of the town. At street level, the promenade is twice as wide as it used to be. Three new pavilions have been built at strategic positions along the water-front, forming the end of important axes and vistas when looking out to see from the town. The interiors of these pavilions offer views to Blackpool and the Lakeland Fells.


CONSTRUCTION / MATERIALS


Coastal defences are required to operate in hostile environments. Waves, wind, tide, sand and saltwater spray act can cause significant damage to defences structure and the erosion of materials over time. The construction at Cleveleys consists of large steel-sheet piles at the foot of the structure, filled with earth behind, and finally capped with a series of interlocking precast concrete lengths of stair. There are 15 sections, each weighing 15 tonnes and prefabricated in a production facility, shared by different flood defence works taking place up and down the coast. The micro silica concrete and granite aggregate was specially designed locally in order to optimise strength and resistance to erosion from the harsh coastal environment.
 

Last updated Tuesday, January 21, 2014

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