New strategies in stormwater-meltwater management in the city of Bergen, Norway

In the City of Bergen, Norway, extensive measures against point pollution sources are now to be implemented and to be finished before the end of year 2000, improving the receiving water conditions. Local politicians and public opinion support high standards of receiving water, even higher than the national level. Future improvements in the receiving water quality is planned through different measures aimed at reducing stormwater-meltwater runoff which causes surface pollution wash-off and combined sewer overflows. The city is now presenting a master plan for the water environment and urban runoff management. One of the main issues of the plan is measures for stormwater-meltwater quantity and quality problems. This paper describes the background for the plan and the reasons for introducing new strategies in integrated stormwater-meltwater management. The non-polluted stormwater-meltwater is to be handled near the source by percolation and/or detention. The polluted stormwater-meltwater is to be collected and conveyed to an appropriate site for treatment and discharge. The alternative drainage system named the Sandsli-system is described.