Shallow understanding

 

Reader Brandt Mannchen takes issue with rainwater harvesting as presented in a recent article (“Letters,” HCN, 5/25/15; “Tucson’s rain-catching revolutionHCN, 4/27/15)). He deplores local Tucson water expert Brent Cluff’s belief that “water harvesting could support unlimited growth.” I know of Brent Cluff but have never heard of and certainly do not share this opinion. Mannchen’s further characterizations of water harvesting and of Tucson’s landscaping reveal a shallow understanding of both.


Rainwater harvesting is designed to irrigate gardens and landscapes and thus reduce the use of potable sources for these purposes, not to encourage lush lawns. Mannchen admonishes Tucsonans to “Adapt to the desert. Don’t fight it.” My wife and I live about four miles from downtown Tucson. Yesterday we hopped on our bikes and surveyed our and adjacent neighborhoods. In over five miles of biking, we spotted just one residential lawn. Tucson is truly a desert town.


Mannchen asserts that too much harvesting will rob streams and aquifers of needed recharge. He ignores the article’s reference to a study that estimated harvesting reduced water flow by a mere 3 percent. On our property, the total building footprint is roughly 3,500 square feet, compared to the lot size of roughly 11,500 square feet. So if we captured and diverted every drop of rain from our roofs, we would intercept just over 30 percent. Of course, we don’t, and in heavy storms, much of the total rainfall still ends up flowing into the street.


Dale Keyes
Tucson, Arizona