Coastal landfill and shoreline management: implications for coastal adaptation infrastructure

Our coastlines need to be managed into the future taking into account the effect of climate change on rising sea levels, whilst balancing public investment and benefits. There is a strong desire to move to more sustainable shoreline management, which allows coasts to be more dynamic in less developed coastal areas. Rather than rigidly defending and holding the existing coastline, shoreline management plans now consider the benefits of "managed realignment" and "no active intervention" policies. However, there is an important legacy of hundreds of coastal landfills located in flood plains around our coasts, including estuaries. This constrains a dynamic policy for shoreline management as storms and rising sea levels may lead to increased flushing of contaminants into the environment and erosion of the landfill may result in the direct exposure and release of potentially hazardous waste. It raises the question about the ability to move/process these landfills (facilitating a move to more dynamic coasts), or alternatively to continue to protect these sites under rising sea levels, potentially creating a lock-in to defence infrastructure approaches.

This project aims to apply NERC-funded and other relevant research at the University of Southampton, together with CIRIA generic guidance C718 on "Guidance on the management of landfill sites and land contamination on eroding or low-lying coastlines", to better understand the effective long-term management of coastal-located waste sites on dynamic coasts. In the context of shoreline management planning it will assess a series of different management approaches that have the potential to address the difficulties that coastal landfills pose.

We will identify 3 to 4 coastal landfills from Lyme Regis to Shoreham and consider their impact on three shoreline management plan strategic options (hold the line, managed realignment, and no active intervention) for two different climate change scenarios. Pollution risks arising from the dual hazards of flooding, leading to the release of contaminated water (leachate), and erosion of the landfills will be considered along with the potential for resource recovery from the old site in any options that involve moving and/or remediating the waste in situ.

Our project partners are the Environment Agency, SCOPAC (Standing Conference on Problems Associated with the Coastline) which is an influential network of local authorities and organisations with an interest in the management of the coast of central southern England, the Eastern Solent Coastal Partnership and the Channel Coastal Observatory hosted by New Forest District Council.

Keywords: Shoreline Management, climate change, sea level rise, flooding, landfill

The impacts will be significant given that there are hundreds of landfills in threatened coastal locations around the coast of UK. Currently there is limited attempts to address this issue strategically. Our outputs will facilitate better methods to analyse this problem and promote strategic analysis which will more effectively manage and reduce the waste hazard. The benefits will be felt over the long term as more and more coastal landfills will become management issues over the coming decades. The main envisaged users are maritime local authorities who are responsible for these orphaned landfills. In addition, the EA with their flood plain management responsibilities will also benefit, as will landfill operators. The expected impact is better long-term planning of shoreline management, including recognising and addressing the management of landfill issues in a strategic manner.

The results will consist of better guidance on of how to manage contrasting old landfills on dynamic coasts including integration with shoreline management planning. These will be presented at relevant end-user meetings selected with our partners and/or webinars. In addition, the outputs of this research will be disseminated by CIRIA via publication or an industry briefing (with EA financial support to cover any costs). The material will also be hosted/linked to the EA and SCOPAC (an influential network of local authorities and organisations with an interest in the management of the coast of central southern England - see section 6) web sites. The impacts will initially be measured by the use of the reported results via download statistics. Over time the application of the methods will be recorded by the EA who have oversight of all shoreline management activity in England. We will engage with relevant organisations in Wales, Scotland and Northern Ireland. The impacts will take place over a much longer timescale of multiple years and decades.