Raingarden
A procurement auction for low impact development (LID) measures was piloted in the Oslo city neighbourhood of Grefsen in 2019, in a collaboration between the Water and Sewage Agency of Oslo Municipality and the Norwegian Institute for Water Research (NIVA) within the action research project New Water Ways. LID measures included rain gardens, rain bar­rels, green roofs and permeable surfaces. A target group of 462 households received a survey and bidding sheet in which they stated their maximum willingness to pay for implementing the different measures. The auction resulted in rain gardens, permeable driveways, green roofs an rain barrels being implemented on the auction winners’ properties. Auction winners co-funded the LID measures, with the difference between the construction cost of the measure and their bid being co- funded by Oslo Municipality and NIVA. The Water and Sewage Agency managed the construction of the measures, and developed guidance information for maintenance. For these reasons, this is classified as a co-operative instrument, while it the procurement auction mechanism itself is an economic instrument.