On July 18, 2017, the coastal village of Coverack in southwest Cornwall was hit by major flash flooding, causing extensive damage to homes and roads.
Given the anticipated increase in sea levels due to climate change, Coverack’s location makes it particularly vulnerable to coastal erosion.
Therefore, we were commissioned by CORMAC Solutions, on behalf of Cornwall Council, to undertake the optioneering, outline and detailed design for a scheme to prevent further erosion of the cliff and safeguard the access road to the village.
What was AECOM’s role in the Coverack North Coast Protection Scheme?
From conducting coastal numerical wave modelling and ground investigations to delivering coastal, geotechnical and AIP-certified detailed designs to supervising the site during construction, our work on the coastal protection scheme was multifaceted.
We also undertook various tasks related to planning, environmental permitting, stakeholder engagement and consultation, such as securing the necessary planning permissions, common land applications and marine licenses for the project.
To do this, we consulted with environmental bodies such as Natural England and prepared reports including the environmental impact assessment (EIA) screening and Water Framework Directive.
Strengthening coastal resilience
Following an extensive optioneering study, we divided the scheme into two parts, each protected by different structures. One section includes a robust barrier composed of large rocks, while the other part integrates this rock barrier with a retaining wall.
With a lifespan of 120 years and the capacity to withstand severe storms for the next 50 years, the retaining wall not only ensures long-term protection to the main access road but also merges seamlessly with the existing sea walls, improving resilience for village against coastal risks.
Protecting one of Cornwall’s most important geological sites
The design process was not without its challenges. As the site is designated as a Site of Specific Scientific Interest (SSSI), our team had to minimise the scheme’s footprint to preserve the intertidal environment and avoid unnecessary excavation.
Given the sensitive nature of the work, coordination was critical between the design and construction phases. Working closely with the project’s key stakeholders including the UK government’s environmental advisor and CORMAC (civil engineering contractor), we overcame site access challenges, opting for barge-delivered rocks to reduce local disruption.
With a lifespan of 120 years and the capacity to withstand severe storms for the next 50 years, the retaining wall not only ensures long-term protection to the main access road but also merges seamlessly with the existing sea walls.
Creating a sustainable legacy for Coverack
Thanks to our expertise, we helped the client achieve significant cost savings and deliver added value as a result. Firstly, by finetuning the design, we ensured the scheme fit within their budget.
Secondly, as well as reducing the length of the scheme at the northern end (cutting costs by £500,000), we refined the design and footprint at the southern end to address any potential environmental concerns.
Our team not only managed to complete the project on time and within budget – eliminating the need for external subcontractors – but we went beyond the original scope of works, adding items such as a temporary road diversion assessment and a common land planning application.
Now complete, this £3.3 million scheme will help protect Coverack’s coast and residents for generations to come and set a strong standard for addressing climate challenges whilst preserving natural geological features.