Not only do urban trees make you feel younger, healthier and wealthier (adding just 10 trees to an urban block can give residents health benefits equivalent to being seven years younger or getting a $10,000 raise, according to study using data from Toronto), they are also important infrastructure that can help reduce flooding and aid in stormwater management.
RAIN Community Solutions, in partnership with LEAF – Local Enhancement and Appreciation of Forests and the Green Infrastructure Ontario Coalition, is holding a webinar 7 October, 1-2 p.m. ET, to help municipalities get the most out of their trees for stormwater management.
“We’re very lucky to have urban tree expert Peter MacDonagh presenting,” says Clara Blakelock, GCC Coordinator of Water Programs. “He’s worked with cities in Canada and the U.S. to improve their urban tree policies and manage more stormwater with trees, and will be able to share the most up to date science and policies.”
Each tree is different in its ability to manage rainfall. Healthy, mature trees provide the most benefits. However, many urban trees are hampered by hostile growing environments and never make it to the mature stage.
Municipalities can help by:
- requiring minimum soil volumes for newly planted trees (healthy trees require 1 m3 of soil for every 1.6 m2 of tree canopy), using tree trenches or tree boxes that maintain uncompacted soil, even underneath paved surfaces;
- directing runoff from roofs, sidewalks, or roads at trees;
- and encouraging a diverse tree canopy so disease and blight are less likely to devastate the entire canopy.
Some Canadian cities have already begun to consider trees as infrastructure. Toronto requires 40% tree cover on all new developments as part of its Green Standard, and also requires that each tree have at least 30 m3 of high quality soil. Vancouver is implementing a comprehensive urban forest policy designed to increase the urban canopy and treat trees as green infrastructure.