1. Case Kuninkoja- Stormwater investment and stormwater programme of Turku 11.11.11 Tallinn Olli-Pekka Mäki

2. Management of stormwaters Traditional Flood prevention Drying Complete Returning water cycle close to natural: Reduction Detention Vaporation Storage Infiltration Based on drainage areas Utilisation Natural Solutions using biodiversity: Green roofs Ponds Wetlands Biofilters Vegetation Effects on scenery and waterbody

3. Background information Kuninkoja –brook: Drainage area 27 km 2 Length of the main channel 7 km Built area 30 % Fields 9 % Forest 40 %

4. Locally valuable scenery element Diverse habitat: bogs, meadows, groves (oak, ash) 10 fish species have been observed ~1 km of 7 km channel length is constructed area and water flows in pipes

5. Cluster of space demanding shops have been build in three years 2008- 2010 ~ 440 000 m 2 No measures taken to delay the stormwater runoff to Kuninkoja Flooding has increased Situates outside city border

6. Stormwater planning and investment Target is to –prevent the disadvantages of flooding –increase the use of surface water elements in planning and construction of parks and greenery areas –decrease rapid water level variations in brook –maintain biodiversity Environmental and City Planning Department responsible for planning Real Estate Department resbonsible for constructing and maintaining Budget of stormwater measure is ~ 61 000 € Construction during 2012

7. Stormwater plan Flood reservoir of ~2000 m 3 Planting of wetland plant species Meandering of channel

9. Thank you!

10. ParameterAverageRange Cond.40 mS/m28 - 50 pH7,87,1-8 SS7,6 mg/l<2 - 23 Coliform2100 /100ml 770-4400 BOD 7 1,2 mg/l0,8 - 1,5 P tot 47 µg/l30 - 110 N tot 1650 µg/l1500 - 1750 Oil0,046 mg/l ParameterAverageRange Cond.35 mS/m21-44 pH7,67,3-7,7 SS15 mg/l10-27 Coliform68000 /100ml 500-200000 BOD 7 5 mg/l1,2-8,6 P tot 63 µg/l54-82 N tot 15501200-1800 Oil< 0.04 mg/l ParameterAverageRange Cond. 46 mS/m42-56 pH 8,37,8-9,8 SS 10,4 mg/l5,2-21 Coliform 970 /100 ml 8-2800 /100 ml BOD 7 1,8 mg/l1,2-2,3 P tot 82 µg/l34-150 N tot 2320 mg/l1400-3300 Oil 0,11 mg/l ParameterAverageRange Cd< 0,1 µg/l Cr3,3 µg/l1,3-3,6 Cu0,01 mg/l0,008-0,014 Pb< 1 Quality of stormwater in Turku