Ezousa Managed Aquifer Recharge — Treated-Effluent Recharge Against Seawater Intrusion (Paphos, Cyprus)

Cyprus is among the most water-scarce countries in the Mediterranean. The Ezousa riverbed aquifer near Paphos lost much of its natural recharge after the Kannaviou dam was completed in 2005, which reduced upstream inflow and triggered seawater intrusion along the coastal aquifer.
Since January 2004, the Water Development Department has operated a managed aquifer recharge (MAR) scheme that feeds tertiary-treated effluent from the Paphos wastewater treatment plant into a series of infiltration ponds along the Ezousa riverbed, recharging 9,000-12,000 m3/day (roughly 2-3 million m3/year) and creating an estimated 4.2 million m3/year of effective storage. Total investment was about EUR 4 million, split between the tertiary treatment and conveyance infrastructure (EUR 3.9 million) and the recharge ponds, boreholes and pumps (EUR 0.1 million).
Independent monitoring found that total phosphorus is strongly absorbed and attenuated as it passes through the aquifer matrix, and that the scheme provides water for irrigation during the dry season. Nitrate attenuation is weaker, and researchers note that the recharge only partially offsets the saltwater intrusion caused by the loss of upstream flow - it cannot fully substitute for natural recharge.
The Ezousa scheme sits within Cyprus's broader wastewater reuse strategy, which recovers a large majority of the country's treated effluent for irrigation and aquifer recharge. It is documented in the EU's Natural Water Retention Measures (NWRM) case-study platform and in peer-reviewed hydrogeological research on coastal aquifer efficiency.

Read the full analysis: https://www.nwrm.eu/case-study/ezousas-artificial-groundwater-recharge-treated-effluent-cyprus