As weather patterns increase the erosion of our coastline will speed up, meaning we not only lose land but also a diverse natural environment. David Chadwick outlines a new way to protect it
Along the West Somerset coastline we have a number of coastal issues - hardly surprising as we have the second highest tides in the world. These range from coastal erosion at Watchet which threatens to wipe out a section of road, and the intentional breaching of the sea defences at Porlock after deciding that it was cheaper than keeping the sea at bay.
Being a densely populated island and having a propensity for building on our picturesque coastline, or in vulnerable wetland locations, we have similar problems all over the country. Hence my interest in ECOncrete technology, which provides a more environmentally sensitive solution to the problem than throwing large rocks at it or raising the white flag.
ECOncrete is an international eco-engineering company which provides environmentally-sensitive concrete infrastructure solutions. In the USA it has partnered with the Seaview at Shark River Island Homeowners Association, American Littoral Society, and Neptune Township to stabilise their vulnerable and eroding shorelines, reduce flood risk, protect critical infrastructure, and expand the marsh buffer for a community along Shark River Island. The full-scale installation follows a two year pilot project that was granted approval by local and federal regulatory authorities
In comparison to traditional concrete erosion control infrastructure, ECOncrete's technology enables a biodiverse ecosystem of marine life to grow on concrete. This infrastructure provides an ecological alternative to traditional concrete and constitutes an environmentally-sensitive shoreline erosion control plan.
ECOncrete has installed 42 innovative marine mattresses at the site, home to a community of approximately 200 townhouses. The ecological concrete mattresses will be coupled with two additional flooding and erosion control structures, a nearshore sill and an upland berm to help dissipate wave energy and protect the adjacent marsh area. The area will be restored and planted by a volunteer effort organised by the American Littoral Society.
The contractor for the project, Renova Environmental Services is responsible for the regrading of the shoreline, placement of the marine mattresses, construction of the nearshore sill, regrading of the eroding marsh and creation of the terrestrial upland berm habitat. Construction began in July.
An initial site visit was performed in the spring of 2016 with the president and property manager of the Homeowners Association, as well as the Neptune Township's Director of Engineering and Planning, and funding approved by the Seaview at Shark River Island Homeowners Association for the design and construction of the living shoreline.
To ascertain how well it worked, a two-year pilot project was deployed at the site to monitor the performance of the mattresses in the intended environmental conditions, and positive results were submitted to the local state and federal permitting agencies who authorised of the full installation. The American Littoral Society provided support in the forms of ecological advice, design support for the marsh sills, planting plans, agency coordination and logistical support, both towards the completion of the restoration of the marsh area and landscaping of the upland berm area with native vegetation.
Once established, the native plants will help reduce the potential for further erosion, and, as we see in this country when our coastal regions are threatened, the initial marsh re-planting will be undertaken and led by volunteers. For the US, read the littoral society www.littoralsociety.org and for the UK it would probably be supported by the National Trust www.nationaltrust.org.uk or a proliferation of local bodies and organisations.
Post-installation monitoring will have to take place over the course of several years to evaluate the performance of the overall project, with the scientific results being paramount towards the future use of nature-based infrastructure measures throughout the region.
Andrew Rella, PhD, Technical Director of Business Development, ECOncrete Inc., said: "We are extremely proud to have implemented our pioneering bio-enhanced marine mattresses at Shark River Island. This is a truly unique partnership, having first been approached back in December 2015. Our aim is to create a hybrid living shoreline to prevent the ongoing erosion between the marsh and marina bulkhead at the northwest corner of the Island and to provide an ecological uplift across the site."
Capt. Alek Modjeski, the Habitat Restoration Program Director of the American Littoral Society stressed the importance of the project. "This area has suffered heavy erosion that not only impacts nearby residences but also the local ecology. The Littoral Society believes this hybrid living shoreline will help reduce the waves, boat wakes, and currents that have affected the marsh and make the surrounding area more storm resistant, while also providing habitat for a host of wildlife. As part of the project, we will be planting native grasses in the eroded marsh along with native shrubs and grasses along the newly created upland berm. Our partnership with Stockton University has also enabled us to stake proper marsh elevations, meaning the plants will also have a better chance of establishment before storm season."
Perhaps this project could also serve as an example for the constantly evolving coastline of the UK.