On the blue planet, and especially in the industrialized world, water is seemingly everywhere. At the turn of the faucet or the flush of a toilet, our control over our water supply is misleadingly large.
Although the planet is covered in more than 70 percent of the stuff, only three percent of it is actually drinkable -- a percentage we are continually diminishing with pollution from our sewer, agricultural and industrial systems.
And even though personal anti-wasting steps (turning off the water, taking shorter showers, etc.) are in order and necessary, these measures alone will not be enough to mitigate massive global water depletion.
What's needed, argues Editor at Large for Sunset magazine Allison Arieff, in her article Blue Is the New Green, is a global effort to make use of water multiple times over. Her top conservation and reuse solutions, which include living roofs, living walls, greywater and rainwater harvesting, are ideas that we often champion. She provides a quick history of each, and discusses how they've transitioned from little-understood fringe details to stylish, practical and tested systems in mainstream building markets. It's refreshing to see worldchanging design solutions like these turn up so prominently in mainstream discussion:
Living Roofs Living (or “green”) roofs are one of several integrated water management systems. Vegetation is ideal for managing water, and provides benefits that are otherwise hard to capture. Green roofs have overcome their once-ingrained association with ‘70s-style earth architecture, thanks to improved technology, better aesthetics and increased building incentive programs like tax abatements (New York approved such a program back in August; 55,000 new square feet of green roofs were installed last year alone in cities including Chicago, San Francisco and Washington, D.C.).
Living Walls But despite their fantastic appearance, living walls are highly practical: they absorb and filter storm water, which reduces local water body pollution and helps prevent the overwhelming of municipal storm water infrastructure. (An urban example by architect Cesar Pelli, which is slated to receive LEED Platinum certification, is shown below). They also filter air particulates, improving air quality and help to reduce the urban heat island effect (UHI). Living walls can also be installed in building interiors, where they not only improve air quality but add humidity to the air when central heating is used in the winter.
Greywater Much less exotic but far easier to implement are greywater systems. Grey water describes water post-shower, -dishwasher or -laundry. Its use will reduce demand as well as sewer-system loads and the amount we pay for our water bills. A simple system of tubing allows one to repurpose this water for landscape watering (which, not incidentally, accounts for 50 percent of home water use in most districts.) So complex is the bureaucracy to install such systems that an organization called Greywater Guerrillas exists to offer DIY advice and workshops on sustainable water infrastructure to the public.
Rainwater Harvesting Rainwater harvesting requires little more than a few barrels. For every 1,000-square-foot catchment area, one inch of rainfall can result in 600 gallons of rainwater, which can be used primarily for irrigation, toilet flushing and fire safety. A recent product launch may help transform rainwater collection into high design: minimalist, olive-toned Rainwater HOG collection tanks are now sold at modern furniture emporium Design Within Reach.
For more articles on water, see our archives:
Great comments! The key is to approach each building holistically. Evaluate all sources of harvestable water - rainwater, greywater, groundwater, even condensate from the cooling system. Then look at how to best retain and use those water sources - whether actively to flush toilets and irrigate landscaping, or passively in green roofs, bioswales and subterranean groundwater recharge.
If you would like more information on water harvesting - particularly in commercial and institutional buildings, visit
Wahaso.com. In addition to good general information on water harvesting, there is a rainwater calculator that will determine the amount of rainwater available to a building for harvesting. It will also calculate the amount of harvested water necessary to flush toilets in a building.
Related solution for wasting energy water:
I recommend it. It's cool!!
I'm very glad to see the mention of HOG rainwater collection tanks. I hope they'll become a popular item and proliferate widely. The fact has recently impressed itself on my attention that every house and indeed every building in my community already perforce possesses a rainwater catchment system in the form of drainage gutters conducting rainwater from roof to ground. So far as I can tell, no additional investment would be necessary besides the installation of these tanks, and maybe some relatively minor modification of drainpipes, to collect vast quantities of rainwater for household or community use. Every time it rains on a large city like, say, San Francisco, millions and millions of gallons of fresh rainwater just drain away, flooding streets and ultimately dumping into the bay. At the same time, in suburban towns huge quantities of water go into watering people's lawns and yards. Catchment systems could do much to obviate the water wastage inherent in our current arrangements.