Influences of Four Extensive Green Roof Design Variables on Stormwater Hydrology
Publication: Journal of Hydrologic Engineering
Volume 22, Issue 8
Abstract
This study assesses the relative influence of four independent variables on green roof hydrological performance under rainstorm conditions. Twenty-four extensive green roofs representing all combinations of the following four design factors were used: native meadow species versus Sedum; mineral-based versus biologically derived planting medium; 10-cm versus 15-cm depth; and irrigation provided daily, sensor controlled, or not at all. From events covering the period May–October in 2013 and 2014, mean values were determined for the seasonal volumetric runoff coefficient (), peak runoff coefficient (), and U.S. Natural Resources Conservation Service (NRCS) curve number (). Irrigation had the largest overall impact: daily irrigation increased to 0.5 compared to 0.3 for systems with sensor-controlled or no irrigation. The biologically derived planting medium, composed of a high proportion of aged wood compost, made a significant improvement, maintaining of 0.3 compared to 0.4 for the mineral-based product in the modules without irrigation. A similar pattern was found in the NRCS curve numbers.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to thank Matthew Perotto and Catherine Yoon for their management of the Green Roof Innovation Testing laboratory (GRIT Lab) at the Daniel’s Faculty of Architecture, Landscape, and Design at the University of Toronto. The GRIT Lab benefits from the support of industrial sponsors Bioroof Systems, DH Water Management Services Inc., GroBark, IRC Group, Toro, and Tremco Roofing, and receives grant funding from the City of Toronto Environment Office, Ontario Centers of Excellence, RCI Foundation, the Connaught Fund, and the Landscape Architecture Canada Foundation. This hydrological study has been facilitated by an Industrial Postgraduate Scholarship from the Natural Sciences and Engineering Research Council of Canada (NSERC) and Flynn Canada Ltd.
References
Allen, R. G., Walter, I. A., Elliott, R., Howell, T., Itenfisu, D., and Jensen, M. (2005). “The ASCE standardized reference evapotranspiration equation.” ASCE, Reston, VA.
ASCE/EWRI Curve Number Hydrology Task Committee. (2009). “Findings and developments.” Curve number hydrology: State of the practice, R. H. Hawkins, T. J. Ward, D. E. Woodward, and J. A. Van Mullem, eds., ASCE, Reston, VA.
Berghage, R., et al. (2007). “Quantifying evaporation and transpirational water losses from green roofs and green roof media capacity for neutralizing acid rain.” National Decentralized Water Resources Capacity Development Project, Pennsylvania State Univ., State College, PA.
Berghage, R. D., Beattie, D., Jarrett, A. R., Thuring, C., and Razaei, F. (2009). “Green roofs for stormwater runoff control.” National Risk Management Research Laboratory, Washington, DC.
Berndtsson, J. C., Emilsson, T., and Bengtsson, L. (2006). “The influence of extensive vegetated roofs on runoff water quality.” Sci. Total Environ., 355(1–3), 48–63.
Bioroof Systems. (2011a). “Bio-mix Eco-blend BIO-010.” ⟨http://www.bioroof.com/_links/TD010_BioMixEcoBlend.pdf⟩ (Jun. 6, 2016).
Bioroof Systems. (2011b). “Bio-mix Euro-blend BIO-011.” ⟨http://www.bioroof.com/_links/TD011_BioMixEuroBlend.pdf⟩ (Nov. 22, 2016).
Blanusa, T., Monteiro, M. M., Fantozzi, F., Vysini, E., Li, Y., and Cameron, R. W. F. (2013). “Alternatives to Sedum on green roofs: Can broad leaf perennial plants offer better ‘cooling service’?” Build. Environ., 59, 99–106.
Bousselot, J. M., Klett, J. E., and Koski, R. D. (2011). “Moisture content of extensive green roof substrate and growth response of 15 temperate plant species during dry down.” HortSci., 46(3), 518–522.
Breuning, J. (2013). “Irrigation on extensive green roofs–Facts study.” ⟨http://www.greenroofs.com/content/Irrigation-on-Extensive-Green-Roofs-Facts-Study.htm⟩ (Sep. 16, 2015).
Buist, R., and Friedrich, C. (2008). “The organic question.” Living Archit. Monit., 17–20.
Carpenter, D. D., and Kaluvakolanu, P. (2011). “Effect of roof surface type on storm-water runoff from full-scale roofs in a temperate climate.” J. Irrig. Drain. Eng., 161–169.
Carter, T., and Jackson, C. R. (2007). “Vegetated roofs for stormwater management at multiple spatial scales.” Landscape Urban Plann., 80(1–2), 84–94.
Czemiel Berndtsson, J. (2010). “Green roof performance towards management of runoff water quantity and quality: A review.” Ecol. Eng., 36(4), 351–360.
Di Gironimo, L., Bowering, T., and Kellershohn, D. (2013). “Impact of July 8, 2013 storm on the City’s Sewer and Stormwater Systems.” City of Toronto.
Easyfit version 5.6 [Computer software]. Mathwave, Spokane, Washington, DC.
Environment Canada. (2013). Canadian climate normals 1981-2010 station data, Fredericton, New Brunswick, Canada.
Farrell, C., Mitchell, R. E., Szota, C., Rayner, J. P., and Williams, N. S. G. (2012). “Green roofs for hot and dry climates: Interacting effects of plant water use, succulence and substrate.” Ecol. Eng., 49, 270–276.
Fassman, E., and Simcock, R. (2012). “Moisture measurements as performance criteria for extensive living roof substrates.” J. Environ. Eng., 841–851.
Fassman-Beck, E., et al. (2015). “Curve number and runoff coefficients for extensive living roofs.” J. Hydrol. Eng., .
FLL (German Landscape Research, Development, and Construction Society). (2008). Guidelines for the planning, construction and maintenance of green roofing—Green roofing guideline, Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.v, Bonn.
GeoDa version 1.6.0 [Computer software]. Center for Spatial Data Science, Chicago.
Graceson, A., Hare, M., Monaghan, J., and Hall, N. (2013). “The water retention capabilities of growing media for green roofs.” Ecol. Eng., 61, 328–334.
Gregoire, B. G., and Clausen, J. C. (2011). “Effect of a modular extensive green roof on stormwater runoff and water quality.” Ecol. Eng., 37(6), 963–969.
Harper, G. E., Limmer, M. A., Showalter, W. E., and Burken, J. G. (2015). “Nine-month evaluation of runoff quality and quantity from an experiential green roof in Missouri, USA.” Ecol. Eng., 78, 127–133.
Hathaway, A. M., Hunt, W. F., and Jennings, G. D. (2008). “A Field study of green roof hydrologic and water quality performance.” Trans. Am. Soc. Agri. Biol. Eng., 51(1), 37–44.
Hill, J., Drake, J., and Sleep, B. (2016). “Comparisons of extensive green roof media in Southern Ontario.” Ecol. Eng., 94, 418–426.
Hill, J., Perotto, M., and Yoon, C. (2015). “Processes of quantifying the hydrological performance of extensive green roofs.” RCI Int. Convention Proc., RCI, Raleigh, NC, 43–50.
Kelly, M. (2008). “A comparative analysis of green roof designs including depth of media, drainage layer materials, and pollution control media.” Univ. of Central Florida, Tallahassee, FL.
Kottek, M., Grieser, J., Beck, C., Rudolf, B., and Rubel, F. (2006). “World map of the Köppen-Geiger climate classification updated.” Meteorologische Z., 15(3), 259–263.
Liu, K., and Minor, J. (2005). “Performance evaluation of an extensive green roof.” Greening rooftops for sustainable communities, National Research Council of Canada, Washington, DC, 1–11.
Lundholm, J., MacIvor, J. S., MacDougall, Z., and Ranalli, M. (2010). “Plant species and functional group combinations affect green roof ecosystem functions.” PloS one, 5(3), e9677.
MacIvor, J. S., Margolis, L., Puncher, C. L., and Carver Matthews, J. B. (2013). “Decoupling factors affecting plant diversity and cover on extensive green roofs.” J. Environ. Manage., 130, 297–305.
Margolis, L. (2013). “Gritlab.” ⟨http://grit.daniels.utoronto.ca/⟩ (Sep. 6, 2014).
Mishra, S. K. (2003). Soil conservation service curve number (SCS-CN) methodology, V. P. Singh, ed., Kluwer Academic Publishers, Boston.
Molineux, C. J., Fentiman, C. H., and Gange, A. C. (2009). “Characterising alternative recycled waste materials for use as green roof growing media in the U.K.” Ecol. Eng., 35(10), 1507–1513.
Moran, A., Hunt, B., and Jennings, G. (2004). “A North Carolina field study to evaluate greenroof runoff quantity, runoff quality, and plant growth.” Green Roofs for Healthy Cities 2004 Conf., Green Roofs for Healthy Cities, Portland, OR.
Nagase, A., and Dunnett, N. (2011). “The relationship between percentage of organic matter in substrate and plant growth in extensive green roofs.” Landscape Urban Plann., 103(2), 230–236.
Nardini, A., Andri, S., and Crasso, M. (2012). “Influence of substrate depth and vegetation type on temperature and water runoff mitigation by extensive green roofs: shrubs versus herbaceous plants.” Urban Ecosyst., 15(3), 697–708.
NCSS version 10 [Computer software]. NCSS, Kaysville, UT.
Oberndorfer, E. (2007). “Green roofs as urban ecosystems: Ecological structures, functions, and services.” Biosci., 57(10), 823–833.
Orange Data Mining versions 2.7 and 3.4 [Computer software]. Bioinformatics Lab, Univ. of Ljubljana, Ljubljana, Slovenia.
Ouldboukhitine, S.-E., Belarbi, R., and Djedjig, R. (2012). “Characterization of green roof components: Measurements of thermal and hydrological properties.” Build. Environ., 56, 78–85.
Rowe, D. B., Kolp, M. R., Greer, S. E., and Getter, K. L. (2014). “Comparison of irrigation efficiency and plant health of overhead, drip, and sub-irrigation for extensive green roofs.” Ecol. Eng., 64, 306–313.
Rowe, D. B., Monterusso, M. A., and Rugh, C. L. (2006). “Assessment of heat-expanded slate and fertility requirements in green roof substrates.” Hortic. Technol., 16(3), 471–477.
Schroll, E., Lambrinos, J., Righetti, T., and Sandrock, D. (2011). “The role of vegetation in regulating stormwater runoff from green roofs in a winter rainfall climate.” Ecol. Eng., 37(4), 595–600.
Starry, O. (2013). “The comparative effects of three sedum species on green roof stormwater retention.” Univ. of Maryland, College Park, MD.
Steinfeld, C., and Del Porto, D. (2008). “Green roof alternative substrate pilot study.”, Executive Office of Energy and Environmental Affairs, Univ. of Massachusetts, Dartmouth, MA.
Toland, D. C. (2010). “Stormwater runoff and plant survival on mock green roofs at the watershed research and education.” Univ. of Arkansas, Fayetteville, AR.
Toronto Water, and Water Infrastructure Management. (2006). Wet weather flow management guidelines, City of Toronto.
Uhl, M., and Schiedt, L. (2008). “Green roof storm water retention - Monitoring results.” Proc., 11th Int. Conf. on Urban Drainage, International Water Association, London.
Van Mechelen, C., Dutoit, T., and Hermy, M. (2015). “Adapting green roof irrigation practices for a sustainable future: A review.” Sustainable Cities. Soc., 19, 74–90.
Van Seters, T., Rocha, L., Smith, D., and MacMillan, G. (2009). “Evaluation of green roofs for runoff retention, runoff quality, and leachability.” Water Qual. Res. J. Can., 44(1), 33–47.
VanWoert, N. D., Rowe, D. B., Andresen, J. A., Rugh, C. L., Fernandez, R. T., and Xiao, L. (2005). “Green roof stormwater retention: Effects of roof surface, slope, and media depth.” J. Environ. Qual., 34(3), 1036–1044.
Voyde, E., Fassman, E., and Simcock, R. (2010). “Hydrology of an extensive living roof under sub-tropical climate conditions in Auckland, New Zealand.” J. Hydrol., 394(3), 384–395.
Walpole, R. E. (2007). Probability and statistics for engineers and scientists, Prentice Hall, Upper Saddle River, NJ.
Young, C. B., McEnroe, B. M., and Rome, A. C. (2009). “Empirical determination of rational method runoff coefficients.” J. Hydrol. Eng., 1283–1289.
Information & Authors
Information
Published In
Journal of Hydrologic Engineering
Volume 22 • Issue 8 • August 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Apr 1, 2016
Accepted: Feb 3, 2017
Published online: Apr 19, 2017
Published in print: Aug 1, 2017
Discussion open until: Sep 19, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.