Hesketh Out Marsh Flood Alleviation Project
Location: Hesketh Bank, England
Value: £2.0m
Role: Alliance Partner
Hesketh Out Marsh Flood Alleviation Project
Major Development Project:
This major Environment Agency project involved the design and construction of a managed realignment scheme at Hesketh Out Marsh West in the Ribble Estuary, near Preston and Southport in Lancashire. This scheme aimed to reduce the risk of flooding on the south side of the Ribble Estuary, without increasing the risk of flooding elsewhere. Once the new embankment had been built, when the original sea embankment is breached, 3.5 square kilometres of saltmarsh is formed in front of the new embankment. This saltmarsh provides a habitat for wildlife and an area for local people to enjoy.
The scheme was developed on previously reclaimed land, to create additional inter-tidal habitat, while maintaining flood defence standards. It has received a Best Practice award from the Institute of Ecology and Environmental Management and was a Commended nomination for a Merit Award from the Institution of Civil Engineers, North West Branch.
With our reputed innovation and technological capabilities, D Morgan created the new flood defence scheme, which used restored saltmarsh to absorb wave energy, thus successfully tackling the effects of climate change on the Lancashire coast in the Ribble Estuary. Our remit included:
- raising and widening the existing inner embankment to a height of 7.8m, using material from excavations that had created new lagoons
- ensuring that the outer embankment could be breached, to allow tidal interchange between the site and the Ribble Estuary
- creating an area of wetland within the area of tidal interchange, and within the confines of the site
Our Involvement as Alliance Partner:
With the climate changing and the sea level rising, the Environment Agency recognised the need to plan for the future and create stronger sea defences, creating new estuarine saltmarsh habitats to replace losses elsewhere. Responding to the needs of the Client and of the environment, we were able to provide value engineering solutions and cost-effective expertise to the project. D Morgan’s managed realignment process effectively soaks up some of the energy of the sea, before it reaches the strong, new sea defences. Taking advantage of good weather, we accelerated the works by working longer hours and bringing more resources to the project.