Ezousas artificial groundwater recharge of treated effluent in Cyprus

National Id
Site name
Ezousas riverbed aquifer (Paphos)
The coastal part of the Ezousa riverbed aquifer, stretches up to 8 km from the coasts of Pafos district. The measure implementation concern the utilization of the local aquifer as a natural reservoir for natural filtration, storage and reuse of water, by creating and feeding infiltration ponds located in the riverbed. The water consists of tertiary treated sewage originating from the Paphos sewage treatment plant.
Κύπρος (Kýpros)
RBD code
Data provider
Ayis Iacovides, I.A.CO
NWRM(s) implemented in the case study
Climate zone
warm temperate dry
Mean rainfall
Mean rainfall unit
Average temperature
Mean evaportranspiration
Mean evaportranspiration unit
Mean runoff
Mean runoff unit
450 - 600 mm
Average runoff coefficient
Average imperviousness
Case Study Info
Light or indepth?
Average slope range
Vegetation class
Unvegetaded riverbed
Monitoring impacts effects
Monitoring location
Monitoring parameters
EC, Boron, pH, P-total: monthly; biochemicals, heavy metals and persistent
organic compounds: every three months
Monitoring upstream station
The sampling data for these analyses are obtained from eight locations: the entry to the infiltration basins, the six abstraction boreholes, and one observation borehole upstream of the recharge site for the native groundwater.
Monitoring downstream station
The sampling data for these analyses are obtained from eight locations: the entry to the infiltration basins, the six abstraction boreholes, and one
observation borehole upstream of the recharge site for the native groundwater.
Performance impact estimation method
Catchment outlet
Performance impact estimation information
A three-dimensional finite element model of the area was constructed using the FEFLOW software to simulate the groundwater flow conditions and transport of Phosphorous and copper in the subsurface from the recharge process. The model was calibrated using hydraulic head and chemical data for the time period of 2002-2011. The groundwater model was coupled with a geochemical model PHREEQC attempting to evaluate nitrate and Copper processes. Inverse modeling calculation was used to determine sets of moles transfers of phases that are attributed to the water composition change in groundwater between the mixture of natural groundwater and reclaimed wastewater and the final water composition.
From the flow model it is suggested that artificial recharge can compensate the lack of upstream recharge only to a point. Thus, a water deficit could potentially be created that will induce the saltwater intrusion phenomenon in the costal area.
The general behavior of phosphorus and Copper was captured relatively well with some exceptions.
Application scale
Installation date
Performance timescale
< 1 year
Area (ha)
Area subject to Land use change or Management/Practice change (ha)
Size unit
Design capacity description
4200000m3/yr is is the estimated effective storage capacity of the aquifer
Max water retention capacity
Max water retention capacity unit
Runoff treatment capacity
Runoff treatment capacity unit
Basis of design
Storage of tertiary treated water in periods of low agricultural water demand.
Aquifer not used for domestic water. Permeable lithologyin unconfined aquifer with sufficient storage availability.
Favourable preconditions
Aquifer previous lithology, sufficient storativity of aquifer, proximity to a STP or availability of treated effluent.
Management change from
No Change
Management change to
No Change
Inflow volume
Inflow volume unit
Contractural arrangements
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Design consultation activity
Activity stage Key issues Name Comments
Design land use change
Land use change type
Beaches, dunes, sands
Design authority
Authority type Role Responsibility Name Comments
National water authority
Water Development Department
Sewrage Board of Paphos
Key lessons
The coastal part of the Ezousas riverbed aquifer, up to 8 km from the coast, is utilized as a natural reservoir for storage and reuse of the tertiary treated sewage from Paphos Town. Tertiary treated water recharges the aquifer through specially constructed shallow ponds. The water after natural purification is pumped again from the aquifer for irrigation purposes. At the same time protection from and control of sea-intrusion is accomplished . The key lessons learned are:
- Artificial recharge with effluent water can be applied in areas with similar geological conditions experiencing droughts and lack of water.
- Conjunctive use of surface and groundwater maximizes the use of available water resources of an area.
†¢ Equal quantities of fresh water for domestic use can be saved by recharging treated effluent and effecting additional treatment which are used then for irrigation.
†¢ Control of sea intrusion is effectively accomplished.
Financing mechanism
Financing mechanism information
In the new water pricing to be implemmented, the irrigation water (fresh or recycled) carries an environmental cost.
Success factor(s)
Success factor type Success factor role Comments
Existing staff and consultant knowledge
main factor

Previous experience with succesful Artificial recharge in riverbed with fresh water.

Financing type Comments
National funds
Barrier type Barrier role Comments
Attitude of the public
main barrier
Especially if aquifer to be recharged with treated effluent serves also domestic supply.
Driver type Driver role Comments
Organisation committed to it
main driver
WDD is responsible for water resources management in the island.
Financing share
Financing share type Share Comments
National funds
Policy description
Aquifer recharge and retrieval of sufficient water quantities of acceptable quality for irrigation purposes. Additionally water purification is achieved and sea intrusion is restricted.
Quantified objectives
3000000m3/yr is recharged into the marginal aquifer.
Part of wider plan
Policy target
Target purpose
Groundwater Recharge
Pollutants Removal
Oher Societal Benefits
Policy pressure
Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
Policy wider plan
Wider plan type Wider plan focus Name Comments
Reuse of treated water effluent and improvement of aquifer status
Policy requirement directive
Requirement directive Specification
Direct benefits information
Pumped water is sold at the price of untreated freshwater.
Costs investment
Costs investment information
Tertiary treatment plant, pumping installation and pipe transfer of treated effluent to the NWRM had a capital cost of 3.9 million euros. On this some 0.1 million euros are added for ponds, boreholes and pumps. These latter figures are to be verified.
Costs operational information
Monitoring staff and operation supervising.
Costs maintenance information
Maintenance of structures after occasional flooding. Renovation of infiltration capacity.Servicing of pumps.
Costs total
Costs total information
Includes ponds (shallow earth walls structures) with simple concrete inlets and outlets. Drilling of wells equipped with pumps, pipes for water transport, monitoring equipment (water levels/meters and quality probes). Staff to monitor and run the NWRM.
Ecosystem improved biodiversity
Information on Ecosystem improved biodiversity
Construction of ponds has overtaken permanently part of habitats. No serious impacts expected on flora although construction works destroyed parts of flora population. Minor impacts on fauna are expected since works overtake parts of riparian habitats.
Ecosystem provisioning services
Information on Ecosystem provisioning services
The site taken by the NWRM is the Esousa main watercourse.
Ecosystem impact climate regulation
Not relevant for the specific application
Information on Ecosystem impact climate regulation
The application in its form does not affect in anyway climate change.
Retained water
Retained water unit
Information on retained water
The Ezousa Recharge Project (ERPr.) is designed to supplement the aquifer with 9000-12000 m3 /day of treated wastewater effluent from Paphos.
Increased water storage
Increased water storage unit
Information on increased water storage
The runoff reduction is nil since treated effluent is brought into the riverbed as an additional quantity of water.
Runoff reduction unit
% Percent
Information on runoff reduction
The runoff reduction is nil since treated effluent is brought into the riverbed as an additional quantity of water.
Ecosystem erosion control
Information on Ecosystem erosion control
The existence of 23 ponds with low retaining walls prevents erosion.
Water quality overall improvements
Positive impact-WQ improvement
Information on Water quality overall improvements
Weak nitrate dilution is observed. Total Phosphorous is strongly absorbed and attenuated into the aquifer matrix. Higher values of heavy metals, compared to the recharging reclaimed water are observed. Sea intrusion is controlled only up to a point.
Soil quality overall soil improvements
Not relevant for this application
Information on Soil quality overall soil improvements
The application of this NWRM does not affect in any way the soil quality except within the ponds themselves.


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