B_Batel_et_J_Harringhton.mp4

Recording of presentations at the Suricates project closing conference

Title : Economic Modelling and Assessment of the Beneficial Use of Dredged Sediments at the La Rance Estuary, France

Authors : Brano BATEL*1, Joe HARRINGTON1 1 School of Building & Civil Engineering and the Sustainable Infrastructure Research & Innovation Group, Munster Technological University, Bishopstown, Cork, Ireland T12 P928 * Corresponding author e-mail: Branislav.batel@mtu.ie

Summary :

Dredging involves removal and relocation of sediments, including from navigation channels, berthing areas and marinas. The management of the sediments generated is a major challenge. The EU Interreg-funded SURICATES project addresses this challenge by seeking to increase sediment use for erosion and flood protection.

An economic modelling and analysis tool (SedEcon) has been developed by Munster Technological University. SedEcon allows analysis of the economic benefits associated with the use of dredged sediment, in terms of Gross Domestic Product (GDP) contribution and the number of jobs created. EconSed provides economic analysis for sediment management projects in the SURICATES partner countries of Ireland, Scotland, France, and the Netherlands with national economic and industry sector specific data included. Economic effects can also be downscaled to a regional NUTS3 level. The tool covers complex sediment use processes including beach nourishment, dyke construction and land reclamation The model has been applied and validated using real site data from completed dredging projects.

This paper focuses on the application of SedEcon to assess the full range of economic benefits associated with the SURICATES capitalisation project at the La Rance Estuary, France. The pilot project used approximately 75,000 m3 of sediment dredged from the La Rance Estuary. The dredged sediment is stored in lagoons at the nearby La Hisse site designed to facilitate dewatering and desalination. The sediment is then used for different applications – agricultural land spreading, dyke construction and concrete wall construction. The agricultural application involves sediment spreading (32,000 m3 ) over 64 hectares of land. Dyke construction assumed 43,000 m3 of dry sediment used as dyke core fill. The concrete application uses the sediment as a substitute for sand in wall construction. The SedEcon results indicate the direct, indirect and induced economic impacts of the different sediment management applications. The direct benefit to GDP for the land spreading application is approximately €276,000 (indirect benefit of €217,000); for dyke construction the model results indicate a direct GDP benefit of €1,715,000 (indirect benefit of €1,367,600). The direct contribution to GDP as a unit cost for the agricultural application and the dyke construction is then approximately €9/m3 and €39/m3 respectively.

Acknowledgements: The SURICATES project is funded by the European Regional Development Fund (ERDF) as part of the Interreg NWE programme 2014-2020.