Kostnader vid anläggning, drift och underhåll av dagvattendammar
The need for knowledge about operation and maintenance of stormwater ponds increases as the number of stormwater ponds in the country increases and the ponds get older. It is partly about how ponds can be managed in a cost-effective way, partly how operation and maintenance efforts should be planned and how they affect the values (alt. ecosystem services) that a pond contributes. Knowledge of operation and maintenance is also a prerequisite for being able to design new sustainable facilities. As there are few studies on the subject, a study was initiated which aims to gain increased knowledge about operating and maintenance costs of stormwater ponds and to relate these to construction costs. By collecting informa-tion via interviews and document studies from 15 municipalities, it turned out that the total installation cost is 990/ m2 SEK. The cost of operation is 36–55,000 SEK/year, and maintenance costs of 320/ m2 SEK for trench dredging and 1,010/ m2 SEK for suction dredging. To be able to compare costs, a typical pond of 4000 m2 was created with a lifespan of 30 and 70 years, respectively. The calculations showed that the installation cost accounts for approximately 40–70% of the annual cost. It also turned out that with marginal extra costs during construction, you can reduce the total costs over a pond’s lifetime.