First in a series
TheDepartment of Fisheries and Oceans slapped a ban on both personal and commercial shellfish harvesting throughout Baynes Sound this week because Sunday’s heavy rainfall, which came “after a prolonged dry spell,” will “adversely affect marine water quality.”
It’s a regular notice the DFO issues around most urbanized regions of Vancouver Island this time of year, and it usually lasts for more than a few days.
Why? Because every time it rains after a dry period, it’s as if a giant toilet flushes animal feces, fertilizers, pesticides, oils, road salts, heavy metals and other contaminants into our municipal stormwater systems, which in turn send torrents of polluted water directly into our watersheds, killing fish, eroding property and making our waters unsafe for shellfish harvesting.
This is not a new problem. For the past 100 years, urban development has replaced natural vegetated land with impervious surfaces like roads and parking lots. This has diminished the amount of rainwater absorbed into the ground and reduced the dispersal of precipitation back into the atmosphere from trees, which do the heavy lifting, and other plants, via a process called evapotranspiration.
To control flooding, Comox Valley municipalities, like other local governments around the world, invested millions of dollars over time in underground infrastructure to channel rainwater runoff into rivers or streams. This not only polluted these waterways and killed wildlife, but the increased volume and speed of the moving water caused erosion and other flooding risks by altering the natural hydrologic cycle.
Even today, when streams get in the way of development, they are often diverted into pipes and buried beneath buildings and parking lots, which greatly increases the flow rate of stormwater and is more likely to cause erosion in a stream’s natural sections.
Comox’s Golf Creek is a prime example. Eighty-six percent of the once flourishing natural stream flowing into Comox Harbor has been buried beneath residential streets, the Comox Mall and the Berwick Retirement Community. It’s polluted after heavy rains and a downstream property owner is currently suing the town over erosion caused by the creek’s sudden fast flows and large volumes.
Former Comox Department of Fisheries and Oceans Officer Chris Hilliar says the problem with stormwater runoff is just the story of urban development gone wrong.
“Humans have an order to their development process: first we log it, then we farm it, then we pave it,” he told Decafnation. “Fish can get along with forestry, if it’s done right; they can get along with farming, if it’s done right; but, concrete and pavement are killers, a death knell to streams and the aquatic life within them.”
The list of problems caused by contaminated stormwater runoff goes beyond erosion and flooding.
Read more at Decafnation.George Le Masurier