Costs and Benefits of Mega-recharge Projects

Over time there are different costs associated with coastal schemes. There is the initial build cost, followed by monitoring and maintenance costs to consider. In addition to this, the frequency of maintenance will vary over the life of a scheme due to long-term degradation and/or changing storm impact. Recharge is often on an annual or 2-3 year timescale. With a changing climate, the recharge frequency and the need for defence is increasing. With beaches becoming squeezed, softer interventions are valuable in terms of socio-economics and ecosystem services. A smaller scheme is considered to be more cost-effective for management epoch 1 (<20 years), while larger schemes are considered more cost-effective for management epoch 3.

With there being multiple benefits arising from mega-recharge projects, it is important to frame the cost not only in terms of coastal defence but also with respect to habitat creation, amenity value, resource efficiency, marketable goods and services etc. Wetlands, for example, are viewed by policy makers as a stock of resources, that have the potential to provide value to people in the form of provision, regulating and cultural services. Other support services provide a benefit such as soil formation, nutrient cycling and habitats. Finally other benefits result from the direct use of the wetlands such as surface and groundwater retention and flood protection. There are also benefits that arise from indirect use such as use for future generations and cultural heritage. In this respect, an ecosystem services framework provides an effective means for assessing the total economic benefit of a mega-recharge scheme.