[All] green infrastructure and roads

[Louisette Lanteigne]

Hi folks
I spoke with Regional Road's staff on the need to secure natural water infiltration zones near roadways today. 
One of the challenges they had in terms of road design was on Townline road with the need to build a road in an area that is basically between two wetland areas. The peat was so dense that it held the water and it wasn't moving it through. The city's crews couldn't remove all the peat without running into major costs. It was compact but when you loosened it up there were so many truck loads of the stuff it was uneconomical to remove it all along the way but they manage to find a sediment type to allow for improved water movement while maintaining the flow rates from A to B so by strategically placing the alternative sediment in spots, they ended up fixing the water issues while retaining many of the area's characteristics with less disturbance. 
I told staff that in order to conserve aggregates we need to build our roads to handle higher precipitation coming down but also to allow for a water infiltration area should waters rise up. The water tables change the lands around us dynamically so we need to figure out ways to allow the flex. I told them when a road crosses a moraine your not dealing with a land of solid foundations. Your building a system that rises and falls like a lung with water. To strengthen existing roads we need to plant lots of trees near them to reinforce the soil with their roots and to absorb water.and allow diversion of water via the root systems to prevent erosion. The roots of the trees, if planted densely enough, creates a snowshoe like effect with the road preventing an area from shifting or sinking reducing aggregates needed for repairs. We also need plants to stop the flow and dispersal of the salt runoff heading to natural areas. The key is to create the spaces for the water to go and use plants to help manage that water. 
Currently road engineering, source protection, regional hydrology and road planning all fall under different agencies. There is no comprehensive dialogue happening on this issue. If we built roads with trees to prevent erosion, to assist with water management issues and to provide a long term structural support while preventing water issues it could mean less road repairs flooding or aggregate needed over the long term. More shade, more carbon offsets does sound good. The GRCA already has a mandate to plant a million trees. If we pair that off in areas where roads need trees it could be a double benefit for taxpayers to save money. 
Here is a quick report by Cornell U featuring a handy list of salt tolerant trees. http://www.gardening.cornell.edu/woodies/pdfs/saltinjury.pdf
In the attachments is a photo of a road built in the third or fourth century in Greece. It was designed for carts and it's held up for centuries. It's made of Limestone with previous areas in between but also allows for controlled drainage on either side that separates the natural areas from road runoff. Look how well this old system held up! 

Also today in the news:
Justin Trudeau is banning oil tankers from BC which is a mighty blow against Enbridge. http://www.bloomberg.com/news/articles/2015-11-13/canada-to-ban-tankers-on-north-pacific-coast-in-blow-to-enbridge

The Canadian Federal Government just posted the mandate of all it's federal ministers online at this website. Very important info to have because mandates govern policy. If you intend to work with a ministry, craft your arguments to fit that mandate! http://pm.gc.ca/eng/ministerial-mandate-letters
Lulu 
      From: John Jackson <jjackson at web.ca>
 To: "GREN >" <all at gren.ca> 
 Sent: Friday, November 13, 2015 6:32 PM
 Subject: [All] green infrastructure and roads
   
You may be interested in the latest story on the Greater Lakes project that I have been coordinating. This story is on green infrastructure and roads.  http://www.metromodemedia.com/features/roadways-impact-waterways-111215.aspx
John

------------------------------John Jackson17 Major StreetKitchener N2H 4R1519-744-7503




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