The Faial demonstrator site will study, design and build an aquifer storage and recovery system, using excess potable water accumulated in existing earth dams/watering ponds, to re-establish the fresh water supply capacity of Furo das Cancelas.
The interface between freshwater and seawater in coastal aquifers is highly dynamic and sensitive to changes in the hydraulic gradient between sea- and groundwater levels. Sea level rise, storm surges, and droughts are natural drivers changing the hydrostatic equilibrium between fresh- and saltwater, and this requires a comprehensive analysis of the benchmark case for this well.
Furo das Cancelas has a production of about 5 m3/h, working non-stop 24 hours for the last 50 years, and it is the only water source for a population of about 3,000 inhabitants. It is assumed that 2 to 4 injection wells (preliminary estimation) would be sufficient to counter the saltwater intrusion and enhance the water quality of Furo das Cancelas.
Objective
The design and construction of this aquifer storage and recovery system will follow the methodological sequence applicable to other demonstrator sites. The same applies to the involvement of local citizens and stakeholders and the adjustment of the NbS solution, the full digitalisation of the ponds and wells and the estimation of the cost/benefit of the solution. The monitoring programme will provide data to use the Ghyben-Herzberg lens as a vulnerability indicator for the saltwater intrusion and restoration results