By Christian Pleijel
The island of Oaxen in Himmerfjärden has been a testing ground for low-flushing taps during the year 2020. Without experiencing any deterioration in water flow, each household saved 25 cubic meters of water (20%), which is SEK 270 / year in reduced fee. 3 cranes cost SEK 480, the repayment period is less than two years.
The test was a collaboration between the community on Oaxen, the residents of the tenant-owner association Sjövillan, Värmdö and Södertälje municipalities, and KTH.
The inspiration came from the Irish island of Inisheer, one of the Aran Islands, where 25 households being the island’s largest water consumers got new shower heads, taps and toilets in 2017. The typical Irish family with 2.6 people reduced their water use from 128 to 79 litres per person and day. Inisheer thus saved 2.3 million litres of water in two years, which is necessary because it is a water-poor island forced to import fresh water by barges.
Student Liubov Shkurenko from KTH wrote her Master’s thesis on water and sewage on Oaxen in 2019. It led to Oaxen becoming a test bed, a pilot for low-flush cranes led by senior lecturer Anders Nordström as part of the Pelago project.
Now the students Ellinor Hambraeus and Emilie Andersson continue the work by comparing water savings in the households of Oaxen and Sandhamn Island. Sandhamn is an island with a very uneven load on its water resources due to the large number of visitors in summer: in high season 8,000 people per day. The students want to understand and suggest how to save water. Their Bachelor’s thesis includes surveys, an overview of the latest water-saving techniques for households and they will propose measures!
Islands are beautiful and fragile communities, most of them sparsely populated in winter and densely populated in summer. The large variations wear hard on the landscape, on the people and on the infrastructure, such as water and sewage.
Knowledge on how to save water seeps from isle to isle. Who’s next?
Överboda, AX-227 30 Kökar
The Åland Islands
Tel +358-457-342 88 25