Recent flooding of cities and towns across the world has attracted the attention of an eclectic group of environmentalists, ratepayers and municipal governments. As our cities have expanded, natural surfaces have been covered by vast swaths of pavement and asphalt. The urban collection of wide roads, driveways and super-sized parking lots has turned our landscapes into waterslides and sluices that quickly deliver storm water overland to rivers, lakes and streams.
Our attempts to make water submit to our will have resulted in the creation of and reliance upon curb-gutter-sewer systems that are supposed to collect the rains and divert them for treatment before they enter the waterways from which we get our drinking water. Yet the legacy of curb-gutter-sewer systems is downstream flooding, erosion, effluent dumping as a result of sewer overflows and ultimately, water quality degradation. They have also been responsible for disrupting the natural hydrologic cycle, reducing groundwater recharge and stream baseflow, while turning self-cleansing systems like filtration and sedimentation into things of the past.
Other sources of water contamination such as industrial discharges, seeps from landfills and dumpings into our waterways have been the target of regulators for decades. While these traditional sources of water contamination have not been completely eradicated, programs to monitor, minimize and moderate have reduced the impact of these practices on water contamination.
But while we were busy minimizing the impact of industrial dumping, urban runoff became a significant source of water contamination. In fact, authorities now cite storm water runoff as the second-largest source of pollution for Great Lakes shorelines.
Communities are recognizing that the “end of pipe” solutions they once relied upon are failing them in significant ways and are horrendously expensive to install and maintain. Now some communities are attempting to replicate the natural systems that existed before we covered everything with pavement and other impervious materials. These communities are incorporating urban features that retain water, such as rooftop gardens, wet ponds and dry ponds. Any early Canadian farmer or woodsman would be familiar with the techniques that are now being promoted as “green” best management practices.
Unfortunately, our understanding of these practices is sophomoric – we promote the practices without fully understanding the problem. In every municipality one can find self-styled authorities who delight in donning the environmentalist’s green hat. They call for expanded road surfaces to provide bike lanes; green roofs that are good for moderating a building’s temperature but don’t make a dent in cancelling out the hydrologic damage caused by a Walmart parking lot; and accept without question our apparently insatiable appetite for paving over bio swales, treed lots and vegetation while eschewing helpful options like permeable pavement, eco grids and increased buffer zones as standard development requirements.
One need only look back at our historic development practices and their legacy of a sprawling network of expensive infrastructure along with the ongoing burden of maintaining and upgrading it to realize how wrong-headed our accepted practices have been. Abandoning the field to environmental dilettantes and hobbyists is no substitute for a system wide approach to earth friendly decision making.