Brief intro to the WaterMan pilot measure

The pilot measure conducted in the Klaipėda District Municipality in Lithuania created a retention pond that collects and naturally purifies stormwater from a 110-hectare residential area in the town of Gargždai. It is the first retention pond in Lithuania specifically designed for water recycling.

As the water flows from higher to lower levels, various sedimentation processes take place: coarse sediments settle in an upstream basin, while the finer sediments settle further downstream in the main pond, where additional pollutant degradation occurs. The system operates without the need for additional technical equipment, relying entirely on the natural purification capacity of the ecosystem.

The retained water is already being used for street cleaning and for watering green spaces – potentially saving up to 300 cubic metres of drinking water per year. In the coming years, further concepts for its use will be developed in collaboration with other municipalities, water companies and parties interested in innovative water management solutions. In addition, the pond creates natural habitats, enhances biodiversity and provides recreational value for the local community.

Type of pilot measure: Real-world implementation
Location: Gargždai (Lithuania)
Water source: Stormwater collected in a retention pond
Type of treatment: Natural purification through sedimentation and biodegradation in the pond ecosystem
Target water quality: Water class D (EU Regulation 2020/741)
Utilisation: Street cleaning, irrigation of urban green spaces
Return to natural cycle: Infiltration and discharge into the sewage system
Responsible: Klaipėda District Municipality, Klaipėda University
Operational & open for visitors: Since September 2025

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“A Pond Designed for the Future“ - read the full story behind the pilot measure

At first, the retention basin in Gargždai was planned with a single purpose in mind: preventing floods. But long-term climate projections suggest that Lithuania, too, will not only face more intense rainfall, but also longer dry periods. So the planners decided to think a step ahead and ask how the stored water could be used – and in doing so, they turned the town into a national pioneer in water recycling. Read more...

In-depth information on the pilot measure

Pilot measure overview (final status) These slides present the final shape of the pilot measure, including its context, implementation, and key lessons learned.

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The evolution of the concept (until today) These slides give an account of the work process behind the chosen technical-organisational concept, incl. considerations, recommendations and decisions taken at different stages. Scroll through the slides to chronologically follow the iterative “development journey” of the pilot measure step-by-step, from the initial idea to its present status!

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Collection of further materials

Retention pond for water recycling in Gargždai: Technical specification
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Retention pond for water recycling in Gargždai: Base maps
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