Skip to main content
Research article - Peer-reviewed, 2006

The influence of extensive vegetated roofs on runoff water quality

Berndtsson JC, Emilsson T, Bengtsson L


The influence of extensive sedum-moss vegetated roofs on runoff water quality was studied for four full scale installations located in southern Sweden. The aim of the study was to ascertain whether the vegetated roof behaves as a sink or a source of pollutants and whether the age of a vegetated roof influences runoff quality. The runoff quality from vegetated roofs was also compared with the runoff quality from non-vegetated roofs located in study areas. The following metals and nutrients were investigated: Cd, Cr, Cu, Fe, K, Mn, Pb, Zn, NO3-N, NH4 - N, Tot-N, PO4-P, and Tot-P. The results show that, with the exception of nitrogen, vegetated roofs behave as source of contaminants. While in lower concentrations than normally found in urban runoff, some metals appear in concentrations that would correspond to moderately polluted natural water. Nitrate nitrogen is retained by the vegetation or soil or both. Apart from the oldest, the studied vegetated roofs contribute phosphate phosphorus to the runoff. The maintenance of the vegetation systems on the roofs has to be carefully designed in order to avoid storm-water contamination; for instance, the use of easily dissolvable fertilizers should be avoided. (c) 2005 Elsevier B.V. All rights reserved


Extensive vegetated roofs; Heavy metals; Nutrients; Runoff quality; Urban; Sedum

Published in

Science of the Total Environment
2006, volume: 355, number: 1-3, pages: 48-63

Authors' information

Bengtsson, Lars
Berndtsson, Justyna Czemiel

UKÄ Subject classification

Landscape Architecture
Fish and Aquacultural Science
Environmental Sciences related to Agriculture and Land-use

Publication Identifiers


URI (permanent link to this page)