Living a Greener Life
I am knee deep in searching for references and information on environmentally concious watershed management - this being necessary for 2 or 3 of my current school projects. There is a tonne of stuff on the web and I just wanted to post some links.
http://www.nrdc.org/cities/smartGrowth/default.asp
There is a link to a document on affordable green housing - which is short but makes some interesting points.
The long and the short of why urban development is bad for watersheds is simply that large areas of impervious surface change how stormwater acts. It prevents water from infiltrating into the ground - think about how this might effect ground water recharge and how often you need to water your lawn. Instead much of the rainfall runs off hard surfaces like roads and roofs -right into stormsewers and often right into recieving waters. The total volume of runoff is larger and the peak volume is higher. Imagine that you take 2 squares - one made of grass and one made of concrete - place them on a 10 degrees slope and pour a cup of water on upper part of each of them. In short order, most of a cup of water will spill off the bottom edge of the square, while much less water will come off the grass square and it'll take longer for the water to reach the bottom. Now imagine this on the scale of say - Mississauga - and a cats and dogs buckets of rainfall storm in the early spring and suddenly all the ice and sand and oil and dirt that has built up over the winter is swept into the storm sewer and then..... Lake Aquitane and Lake Wabakyne. I can't really pick on Mississauga, since I'm not sure where their storm water goes. The two lakes near my home are examples of wet ponds, a stormwater detention method that allows stormwater to settle out some of the nasty stuff it picks up, and also gives the city control over the speed that the water is released to natural recieving waters. Lake Wabakyne has a very typical shape (in fact the picture of a wet pond in the Ontario Stormwater Design Manual (here is the link for any hard core engineering types - chapter 4 has the nicest pictures http://www.ene.gov.on.ca/envision/gp/4329eindex.htm)
Okay I ran out of time while looking for Peel stuff.
I'll continue the second part of this blog later
http://www.nrdc.org/cities/smartGrowth/default.asp
There is a link to a document on affordable green housing - which is short but makes some interesting points.
The long and the short of why urban development is bad for watersheds is simply that large areas of impervious surface change how stormwater acts. It prevents water from infiltrating into the ground - think about how this might effect ground water recharge and how often you need to water your lawn. Instead much of the rainfall runs off hard surfaces like roads and roofs -right into stormsewers and often right into recieving waters. The total volume of runoff is larger and the peak volume is higher. Imagine that you take 2 squares - one made of grass and one made of concrete - place them on a 10 degrees slope and pour a cup of water on upper part of each of them. In short order, most of a cup of water will spill off the bottom edge of the square, while much less water will come off the grass square and it'll take longer for the water to reach the bottom. Now imagine this on the scale of say - Mississauga - and a cats and dogs buckets of rainfall storm in the early spring and suddenly all the ice and sand and oil and dirt that has built up over the winter is swept into the storm sewer and then..... Lake Aquitane and Lake Wabakyne. I can't really pick on Mississauga, since I'm not sure where their storm water goes. The two lakes near my home are examples of wet ponds, a stormwater detention method that allows stormwater to settle out some of the nasty stuff it picks up, and also gives the city control over the speed that the water is released to natural recieving waters. Lake Wabakyne has a very typical shape (in fact the picture of a wet pond in the Ontario Stormwater Design Manual (here is the link for any hard core engineering types - chapter 4 has the nicest pictures http://www.ene.gov.on.ca/envision/gp/4329eindex.htm)
Okay I ran out of time while looking for Peel stuff.
I'll continue the second part of this blog later
posted by Jennith at 10:34 AM
2 Comments:
Not nearly as useful as Colin's, but I wish I could link to my first year drafting room, we have complete schematics of that weird structure at the end of Aquatain, it was more then just a drain. As I child I used to think that is where they kept the sharks.
I'm jealous - I did find a document about wabukayne - aparently it was dredged in 2003 or so by monahan, mcLaughin marshall. As for the thing at the end of aquitaine I think we learned about them in my course last semester. I should be able to tell you more about them when I finish this project.
night
Jenn
Post a Comment
<< Home