Sustainable Stormwater management International cases Lars Rydén The Baltic University Programme Centre for Sustainable Development Uppsala University Stormwater Stormwater is water that originates from precipitation events and snow/ice melt Stormwater can - run into the sewage system - soak into the soil - be held on the surface and evaporate - run off and end up in nearby streams Urban runoff entering a storm drain in Kharkiv. Early spring SWITCH Sustainable water management in the city of the future www.switchurbanwater.eu • protection of the hydrological cycle • landscape aesthetics • integration with neighbouring land • correctness of design • environmentally: habitat integrity, biodiversity The SWITCH project • Cities in four continents and at various stages of development • All aspects of the water cycle – water, wastewater, stormwater and natural systems • A wide range of climatic, socio-economic and institutional situations • Social, economic and environmental perspectives • Scales ranging from household to city levels • Water as part of urban planning and the built environment • From the present time to the 'City of the Future' Water in the City Sustainable Development Applications Series Edited by Tomasz Bergier, AGH University of Science and Technology Jakub Kronenberg, University of Lodz Iwona Wagner, University of Lodz, ERCE u/a UNESCO PAS Published by The Sendzimir Foundation www.sendzimir.org.pl http://www.sendzimir.org.pl/images/zrz-5-en/ZRZ5_web.pdf Sustainability Challenges for stormwater managment • To be able to take care of a large volume of water during floods • To reduce pollution of the receiving water • To take care of water as a resource • To promote biodiversity • To increase the beauty and functionality of the urbanscape Pervious pavements, asphalt and grass pavers Large surfaces devoid of greenery, such as parking lots, roads and sidewalks cause the most trouble in terms of uncontrolled surface runoff. Green infrastructure is often impossible to apply. It is possible to use materials that allow water to infiltrate, i.e. pervious paving and asphalt. Infiltration basin and footbridge in Aiken, USA Vegetated buffer strips Vegetated grass buffer strips are a good solution in areas with looser development, especially near roads. These slightly inclined vegetated surfaces allow the slow (horizontal and lateral) flow of stormwater from adjacent land Infiltration basin and footbridge in Aiken, USA Curb indentations Curb indentations channel water, allowing it to flow from the streets and sidewalks. Runoff water flowing down NE Siskiyou street in Portland, Oregon, USA Detention basins Detention basin used for recreation during dry weather can collect water from the streets and parking lot. Grangetown , Wales, UK SuDS Wales Sustainable Drainage Systems Infiltration ditches and grass ditches Grass ditch along tramway tracks in the city centre of Freiburg, Germany. Dry detention pond Benthemplein water square in Rotterdam, the Netherlands. Photo during dry weather. Can accommodate nearly 2 million litres of water during rain. Sedimentation – biofiltration system pilot project in the Sokolowka river in Lodz, Poland A large stormwater wetland in Massachusetts, USA Buffer zone with biogeochemical barrier for the pre-treatment of water conveyed directly to the reservoir schematic representation and pilot project in the ponds of Arturowek in Lodz, Poland Sustainable Stormwater System Augustenborg, Malmö Sweden, 1998–2014 Sidewalk Garden Project San Francisco, USA, Established in May 2013 Human– Nature– Technology Sustainable stormwater management Kronsberg, Hanover Germany, concept – 1992, beginning of construction – 1997 Children are playing by the “bächle” in Freiburg, Germany. The “bächle” are small open water channels that follow the streets downhill to the river. Conclusions 1. Acknowledge the importance of water as a natural system that provides a range of benefits (ecosystem services) to the city; a shift in the perception from the need to desiccate the city and perceiving water as a threat to the benefits of increasing the presence of water in a controlled way and seeing water as a resource. 2. Accept the presence of water in the city and design space for it; use technical solutions that enhance stormwater infiltration and retention in the urban drainage basin, and its treatment. 3. Allow the use of best practices in stormwater management alone or in combination with traditional methods (combined or stormwater sewer systems).