Monday, 7 July 2008
Harvesting Water Can Yield a Huge Crop of Sustainability
I never thought of water as a crop until I read an article by Justin Lawson, P.E., in the June issue of PE, the Magazine for Professional Engineers. On average, an American uses 175 gallons of clean water per day, but for cooking or drinking uses barely a gallon. Therefore, more than 99 percent of the water goes down the drain. There are estimates that 50 percent could be reused as gray water by harvesting it to irrigate plant life and other such uses.
Even with detention basins and vegetated swales, most of the rainwater travels along an open or closed system until it releases the discharge into a stream or river. Why not harvest this rainwater? In a roof collection system, this water could easily be used with proper treatment. Creating larger storage impoundments for stormwater upstream is another harvesting technique, one that has not been utilized extensively in this country.
We engineers need to learn these techniques and advocate for more sustainable water environments. This advocacy begins with elected officials and regulators in our local communities. At the federal level, there has been a bill to establish a program within EPA's Office of Research and Development to promote water use efficiency and conservation. The second bill would promote R&D and create a demonstration program for the reuse of water produced during oil and gas extraction.
Has your local community begun promoting water harvesting and reuse? This is a step to building a culture of sustainability that is needed in this country as our limited resources continue to be exhausted.