b'WINR VEGETATIVE ROOFSAN ENVIRONMENTAL DIFFERENCE FOR OUR FUTURE Pam Keiner, Maly Roofing Company, Inc.V egetative Roofs and Waterof a green roof to hold and store water. This water Retentionarebecomingis then released slowly back into the atmosphere increasingly popular oncethrough evaporation and transpiration. The amount again in urban areas to help with our environmentof water a green roof can retain depends on various and to my surprise are even being grown on cruisefactors, including the depth of the growing medium, ships (I assume with waterproofing under, didntthe type of vegetation, and the slope of the roof. look). There are names you may have heard such as Green roofs, also known as living roofs, havePurpleroof,Blueroof,LiveRoofandothers becomeincreasinglypopularinurbanareasdepending on manufacturer naming.recently.They offer many benefits, includingTheObvious-Oneofthemainbenefitsof improved air quality, reduced energy usage, andwater retention on green roofs is the reduction one of the most important benefits of green roofsof stormwater runoff. In urban areas, the large is their ability to retain water. We will explore theamount of impervious surfaces such as concrete concept of water retention on green roofs and itsand asphalt prevent water from being absorbed into importance in this article. the ground. Instead, water quickly runs off these Water retention on green roofs refers to the abilitysurfaces and into storm drains, causing flooding and erosion. Green roofs help to mitigate this issue 30 www.mrca.orgMidwest Roofer'