Ecosystems services valuation: Loss of wetland due to climate change and creation of wetland under proposed "sandscaping" coastal defence schemes

Using a well-established, non-market, valuation technique, benefits transfer methodology, this report provides welfare estimates for three proposed sandscaping sites in Northwest England. This paper uses a methodology proposed by Brander et al. (2010) and further refined by Brander et al. (2012) that scales up values for changes in ecosystem service provision to assess the value added by implementing mega-recharge schemes that would result in wetland creation. The value lost for salt marsh around the Dengie Peninsula if 10% of the wetland was lost due to climate change impacts such as sea-level rise was also investigated. It was found that the loss of 10% of salt marsh in the vicinity of Bradwell-on-Sea would represent a cost to the region of about £1,300,000 per year. If a mega-recharge scheme was built in Barrow-in-Furness, it could bring benefits of more than £1,200,000 per year. For the Fleetwood example, this reduces to £830,000 per year. Despite the wetland area created at Fleetwood being less than half the area of the Barrow-in-Furness option, the ‘value added’ amount is only reduced by a third. This is due to the larger population within 50 km of the proposed Fleetwood site. Finally, the option of an island in the middle of Morecambe Bay creates the smallest new area of wetland and has a lower population within 50 km of the site than Fleetwood, it therefore has the lowest added value of £390,000 per year. These figures are gross annual figures, i.e. the value added to the region annually so long as the area of created wetland remains the same. It is expected that the additional area of wetland would reduce over time and would at some point in the future need to be recharged. The amount of reduction annually and time between recharges would be dependent on the initial design, for example sediment particle size will affect the longevity of the wetland (see sandscaping modelling report). Further modelling could be carried out to investigate the annual size of the wetland area, and the time until recharge would be required, these figures could then be used to give a more accurate annual figure. This work has shown that the loss of wetlands due to climate change could have a large impact on the region in terms of the benefits that the wetlands currently provide. This impact could be mitigated by proposed large-scale sandscaping interventions that create wetland and restore value to the region whilst offering the direct benefit of protection against coastal erosion and flooding