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Circular Water Challenge

This project described water resources, real water needs, and how water can be reused on seven islands in the Baltic Sea (Oaxen, Sandhamn, Möja, Torsholma, Kökar, Korpo and Örö).

Illustration of the seven islands in the project.
The seven islands in the project. Illustration: Christian Pleijel/KTH

Project name: Circular Water Challenge
Project leader: Christian Pleijel, KTH
Participating universities/ companies/organisations: KTH Royal Institute of Technology
Project period: 2018-2019
Financing: Region Stockholm (Sweden), Södertälje kommun (Sweden), Värmdö kommun (Sweden), Ålands landskapsregering (Finland), Kökar kommun (Finland), Brändö kommun (Finland), Pargas stad (Finland), Forststyrelsen (Finland), Nordiska skärgårdssamarbetet.

This study has described the water and sewage situation on seven islands in the Baltic Sea (Oaxen, Sandhamn, Möja, Torsholma, Kökar, Korpo and Örö), based on a model where islands are sliced into three levels: the natural landscape (water supply, hydrogeology, environment), the social landscape (settlement, activities, needs in time and space), and the technical landscape (VA infrastructure including costs). When applying this model to an island, you get a clear picture of the island's water resources, the real water needs, and where it is possible save water by reducing the load on outlets, production and drainage. Three different cases of water reuse were developed during the study, see more in the film and reports.


Film about the findings in Circular Water Challenge on Youtube, 2019


VA-prisets finalister lyfter VA-frågan i storstäder och landsbygd, on VA-Fakta 2020-02-11 (in Swedish)

Ö-samarbete för att spara vatten, in the Nya Åland newspaper, 2019-10-09 (in Swedish) (jpg 1.6 MB)

Vattnet kan räcka till fler på Oaxen, on SVT, 2019-09-27 (in Swedish)

Studenter ska hjälpa öborna att spara vatten, on SVT, 2019-09-27 (in Swedish)

Möjas färskvatten kartlagt, in the Skärgården newspaper, 2019-09-21 (in Swedish)

Återanvändning av avloppsvatten mot vattenbrist i skärgården in P4 Stockholm 2019-07-31 (in Swedish)

Purified wastewater is reused in toilets, on SVT, 2019-05-14 (in Swedish)

Short film about Circular water challenge in the Stockholm Archipelago, 2019-02-08 (in Swedish)

Circular Water Challenge off to a good start!, 2019-01-23


Sju små öar som söker lösningar på sin knepiga vattensituation (in Swedish) (pdf 1.8 MB)

More reports from the project on Box (in Swedish and English)


Christian Pleijel,

Belongs to: WaterCentre@KTH
Last changed: Feb 07, 2022