Best in Flow: A Six-Pack of Decentralized Water Management Systems That Deal with Climate Change Turmoil by Building Local Resilience
YOU JUST TOOK A WATER BALLOON TO THE FACE. The good news is that, as a Canadian, you are rarely so pressed to think about the quality and abundance of your water. Globally, there is enough clean and fresh water for everyone. Nevertheless, huge shortages remain in many parts of the world due to the naturally uneven distribution of the water cycle (among other factors). Even more problematic, the cycle is easily disrupted: small climatic shifts can quickly bring too much or too little, wreaking havoc on conventional water management systems.
These systems are proving inadequate to the challenges created by climate change. Because Canada has been spared the harshest impacts (so far), we are largely unprepared for major water cycle shifts. Fortunately for us, there are lessons to be learned from many communities (including a few homegrown examples) that have already adopted decentralized water management strategies. What we need to absorb are not the designs themselves, but the principles of resilience and low-impact development, which are essential to building a water system that can withstand shocks.
To clarify, the concept of decentralized systems Is intended as a geographical distinction rather than a political one. In this context, both centralized and decentralized systems can refer to public or private and municipal or federal initiatives.
Most Canadian cities use water from a single source and dispose of it in a single location. The system works well enough under normal circumstances; there's no real need to recycle when freshwater remains in ready supply. This centralized structure, however, is like an 18-wheeler on a treacherous highway, struggling to cope with changes in speed and direction. Enough of both, and it might crash.
Increases In the intensity of flooding, droughts and storms are all expected impacts of climate change on water cycles. "New patterns of wind, humidity, and ambient temperature are already dramatically altering the weather map," wrote Chris Wood, author of Dry Spring: The Coming Water Crisis of North America, In a 2005 article. "Some parts of the country are receiving more rain than ever before; other regions are drying up." Moreover, Wood argues that "Canada's multibillion-dollar Investment in water infrastructure" is already outdated: "It will not be able to either contain the massive floods or ameliorate the droughts of the future."
No, perhaps not. An anecdote from our nation's capital may help explain why.
For most of one day in early September 2012, It rained heavily in Ottawa--not an uncommon event for the time of year. or one likely to raise alarms. Yet the capital region's residents were unpleasantly surprised to find that the rainfall had caused 63.5 million litres of diluted sewage to overflow into the Ottawa River. Ottawa's stormwater system is typical of a midsized Canadian city: made up of no less than 1500 kilometres of pipes, including some overlap with the sewage system. The labyrinth of pipes is not designed to handle large influxes of water, and the results are more or less catastrophic when it happens.
Like most of the world, Canada's cities are ill equipped to handle sweeping problems such as contaminated water supplies and widespread flooding. Ottawa's sewer system can't cope with an enormous rain deluge any more than India's water reserves can withstand weeks of drought. Centralized systems are vulnerable to climate change conditions because the size and nature of the infrastructure makes adaptation difficult. Breaking water management structures down into discrete, independent and decentralized systems builds resilience against fluctuation.
ASK international sanitation consultant Julian Doczi about decentralized water management and he will fire back with his own questions: What is the current regulatory environment? What are the specific physical terrain features and urban density of the local area? …