LIFE_FRESHMAN: Sustainable freshwater management in coastal zones

PROJECT DESCRIPTION

BACKGROUND

Drinking water companies worldwide have freshwater supply problems. The main freshwater source for the Dutch water utility company Dunea is the Maas River, together with the Lek. However, due to extreme drought and intrusion of salty water (partly due to rising sea levels), the freshwater provision has become endangered. Groundwater lenses occur where freshwater floats above denser saltwater. Brackish water in these lenses is a promising new resource to supplement coastal freshwater reserves, reducing seawater intrusion and creating a buffer during periods of drought.

OBJECTIVES

The LIFE_FRESHMAN project beneficiaries aim to demonstrate the effectiveness and cost-efficiency of a novel method to enlarge and safeguard freshwater availability, for producing drinking water and safeguarding biodiversity and ecosystems, while creating a buffer for extreme drought conditions. Creating freshwater buffers and reducing dependence on climate-change sensitive freshwater sources, such as surface water, is key to increasing resilience. The objective of the project teams innovative technique, called Freshman, is to enlarge groundwater lenses in coastal zones by combined infiltration of freshwater and extraction of lower-level brackish groundwater. The enlarged lens acts as both a strategic freshwater storage solution and as a barrier against saltwater intrusion. The aim is to treat the extracted brackish water using reverse osmosis, to create a new climate-independent drinking water source. To promote the replication of the projects methodology, results will be disseminated to relevant authorities and professionals across the EU.

The projects outcomes will contribute to the implementation of the EU Floods Directive, Water Framework Directive, Biodiversity Strategy for 2030, and policy specifically aimed at preventing saltwater intrusion and freshwater loss in coastal areas.

RESULTS

Expected results:

A successful demonstration of the Freshman technique, showing it to be a cost-effective adaptation strategy to enlarge and safeguard freshwater availability in coastal areas;

Demonstration of the technique as a freshwater buffer in periods of extreme drought and a barrier to saltwater intrusion;

The strategic fresh groundwater reserve in the demonstration site Meijendel in the Netherlands is expected to increase by approximately 350 000 m3 by the end of the project;

A new source of drinking water, based on treated brackish groundwater, will provide a continuous supply of freshwater through reverse osmosis of 220 000 m3/year (25 m3/hr) at the demonstration site;

The method for combined infiltration of freshwater and extraction of brackish water, both at 50 m3/h, to be replicated at another site - Avekapelle in Belgium;

Guidelines providing for implementation of the Freshman technology in other coastal EU areas;

Implementation of a monitoring plan and publication of monitoring reports, including the monitoring of phreatic groundwater and salinity levels, and vegetation and habitat types;

In the Netherlands, production of maps of vegetation and habitat types, and reports on ecohydrological models and economic and sustainability of brackish water as a drinking water source; and

Reports on hydrology and geology in Belgium, including effects of Managed Aquifer Recharge (MAR) systems, and report on freshwater lens evolution and economic analysis on brackish versus standard water production.

The replication site in Belgium will focus on building up the freshwater lens (that can also act against salt water intrusion) during and after the infiltration. Once this technologiy is proven successful, the system might be found suitable to produce drinking water out of brackish water, in a future stage.