Ever wondered why the streams in your neighbourhood have gotten so wide so quickly? Read this. Something we don’t think about much.
Before gabbing about how I did this and why, I’ll put the answer first (this is for a development area about 500m long and 500m wide):
2005 is pre-development, 2014 is after building five townhouse complexes (over 400 units) and over 150 single family homes. Over 1 million liters of rain falls on the roads on a really rainy day.
I’ve been watching the rain collect on my narrow streets and run down the drain into fish habitat.
Every time it rains, I wonder how development has affected the amount of road runoff that ends up in rivers and streams.
I did some basic analyses to get a general idea. I chose a recently-developed area, about 256,000 square meters (thanks COSMOS mapping program!), and highlighted the roads (not rooftops or driveways…let’s say that developers have used sub-soil gravel diversions and other techniques to divert that runoff into soil).
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