Sustainable drainage systems (SuDS)
Sustainable drainage systems (SuDS) want to manage urban runoff in order to: (i) restore hydrological balance and reduce pollutant loads of water bodies, moving from a post-urbanization back towards a pre-urbanization status of water bodies; (ii) build the so-called Sponge Cities, i.e. cities able to soak the urban runoff and mitigate flood effects; (iii) build green-blue infrastructure able to exploit all the Ecosystem Services of Nature-Based Solutions.
IRIDRA proposes SuDS solutions for sustainable management of rainwater, trying to conjugate the environmental needs with the possibility to restore neglected urban areas.
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The drainage of urban runoff was usually underestimated in the planning and design of current cities. It resulted in serious hydraulic risks once the cities increased too much the cover with impervious surfaces, leading to often urban flood events due to functioning in pressure of sewers. But the current approach leads also to many issues in terms of water quality, due to pollutant load conveyed to water bodies by first flushes and combined sewer overflows.
Source: Woods Ballard et al. 2015. "The SuDS Manual"
Sustainable drainage systems - the concept
Sustainable Drainage Systems (SuDS) want to manage urban runoff to:
- recover the original hydrologic regime and reduce the pollutant loads, moving from post-development back again to pre-development status;
- build future sponge cities in response to heavy rains;
- provide cities with as much as possible new green-blue infrastructures, exploiting the multiple ecosystem services of nature-based solutions
Source: Woods Ballard et al. 2015. "The SuDS Manual"
SuDS and Ecosystem services
Ecosystem services are defined as the "direct or indirect contribution of an ecosystem to human wellbeing".
SuDS techniques provide a number of different ecosystem services additional to that of runoff drainage. For instance, 17 examples of ecosystem services given by SuDS - Soft Engineering - instead of conventional solutions - Hard Engineering - are reported (Huber, 2010):
- atmospheric regulation
- climate regulation
- disturbance regulation
- water regulation
- water supply
- erosion control and sediment retention
- soil formation
- nutrient cycling
- waste treatment
- pollination
- species control
- refugia/habitat
- food production
- genetic resources
- recreation
- cultural enrichment
Source: Huber, J., 2010. Low Impact Development: a Design Manual for Urban Areas
SuDS and Green-Blue Infrastructures
Green-Blue Infrastructure is defined as a network of green and blue spaces exploiting ecosystem services to provide benefit for people and the environment.
Urban park following a SuDS approach in Singapore (Bishan). Source: Gibelli G., 2015, Manuale di drenaggio urbano (in Italian)
SuDS and Sponge Cities
Sponge city is a concept developed in China, in which the city is required to adsorb urban runoff as "sponges" in order to reduce the flood risks driven by increased urbanization. In this clear how a SuDS approach is suitable to develope Sponge cities.
SuDS, WSUD, LID, BMPs ...
The SuDS approach is known in literature with different keywords, developed by research groups of different states. The most known ones are the following:
- SuDS Sustainable Drainage Systems
- WSUD Water Sensitive Urban Design
- LID Low Impact Development
- BMP Best Management Practices
SuDS experiences - International
Atelier Dreiseitl, Potdamer Plaza, Berlin (Germany)
Tanner Springs Park, Portland (USA)
Water Plaza, Rotterdam (Netherlands). Source: Gibelli G., 2015, Manuale di drenaggio urbano
Sydney (Australia). Source: Gibelli G., 2015, Manuale di drenaggio urbano
SuDS experiences - IRIDRA
Open water tanks for climatic regulation with harvested rainwater, Kerakoll research centre (Sassuolo, MO - Italy), designed by IRIDRA in collaboration with BIOS-IS S.r.l.
Bioretention system for sustainable drainage of rainwater, Kerakoll research centre (Sassuolo, MO - Italy), designed by IRIDRA in collaboration with BIOS-IS S.r.l.
Constructed wetland for the treatment of combined sewer overflow of Gorla Maggiore (VA - Italy). The wetland was designed a multipurpose, exploiting different ecosystem services in the new "Water Park" of Gorla Maggiore: water quality improvement of Olona river, flood mitigation, public recreational area, and biodiversity increase. The "Water Park" of Gorla Maggiore was one of the case studies of the EU OpenNESS project.
Urban wetland included in the intervention for the Santa Chiara Open Lab project, financed by Italian fund for suburbs restoration ("Bando Periferie"). The wetland receives the runoff from roofs and is designed as a multi -purpose intervention: treatment and reuse (gardening) of rainwater; flood mitigation; biodiversity increase in the urban environment; aesthetic.
The Eco-Boulevard and the Water Arena for the Lazzareto quartier of Bologna. IRIDRA's proposals for the Climate Change Adaptation of the Bologna Municipality, included in the technical assistance given to Atkins in the study "Climate Change Adaptation and Resilient Cities" (financed by the European Investment Bank -EIB). These proposal were included in the new guidelines of Bologna Municipality for SuDS systems, one of the action of the Bologna Climate Change Adaptation Plan developed under the BlueAP LIFE project.
References
IRIDRA's authors are highlighted in bold.
Masi F., Rizzo A., Bresciani R., Sustainable Rainwater Management in the City: Opportunities and Solutions for the Anthropic Environmental Impacts Reduction and Urban Resilience Increase, in "Smart Metropolia - Przestrzenie RelacjiPublisher: Obszar Metropolitalny Gdansk-Gdynia-Sopot ul. Dlugi Targ 39/40, 80-830 Gdansk, 109-119; 978-83-65496-02-07, 2018.
Huber, J., 2010. Low Impact Development: a Design Manual for Urban Areas. Fay-etteville, AR: University of Arkansas Community Design Center.
Woods Ballard, B., Wilson, S., Udale-Clarke, H., Illman, S., Scott, T., Ashley, R. and Kellagher, R., 2015. The SuDS Manual, C753, CIRIA, London, UK. ISBN 978-0-86017-760-9.