As
I stated in my April 2009 editorial,
due to increased interest in water conservation and
sustainability,
rainwater catchment is “poised to become not just an interesting side note, but
also a powerful tool for water-strapped cities and states.”
(Divining Rods, Elements 2010)
Known as either
rainwater catchment or harvesting, the process is quite simple and can be an
easy first step for any water-strapped community searching for ways to
supplement their current supplies. For example, in Los Angeles, CA, six projects
capture 1.25 million gallons of water for every inch of rain, and there’s no
reason those results can’t be replicated throughout the country.
Rainwater
harvesting may be a no brainer, but it’s mostly been treated as a second-class
citizen, something to ignore or marginalize in the face of (sometimes) flashier
alternatives. But what rainwater catchment lacks in bells and whistles, it more
than makes up for in terms of cost and ease of implementation. In Tucson, AZ,
rainwater harvesting is suddenly in the spotlight. Tucson has just enacted the
nation’s first municipal rainwater harvesting ordinance for commercial projects.
Under this new ordinance, developers of new corporate or commercial buildings
must design all landscape irrigation, so that 50% of the water used comes from a
rainwater catchment system.
Tucson
officials hope that the anticipated 12 inches of annual rainfall will supplement
current municipal supplies (which come from wellwater and the Colorado River),
starting next year. Like Santa Fe County, NM, the Tucson harvesting ordinance
allows for a passive collection system (which mostly diverts run off from
parking lots and roofs), as well as small harvesting combined with pumps and
drip irrigation, but Tucson’s ordinance goes one step further by allowing for
active harvesting as well. The Tucson city
council has also approved an additional measure that requires new homes to have
a plumbing system that would allow for separate drain lines so that a graywater
system can be installed, and water from sinks, showers, and other appliances can
be diverted to the homeowner’s irrigation system.
Because commercial
projects are often a community’s largest water consumer, this ordinance should
have a significant payoff. For example, the latest remodel at Tucson’s Target
included a rainwater harvesting system that catches runoff from the parking lot
and diverts it to towards small landscaped sections that include native plants
and trees, which are designed to hold up to 15,000 cubic feet of water that
would otherwise be lost to storm drains.
So what do you
think? Why aren’t more communities requiring rainwater harvesting? And, are ordinances the answer, or can
public outreach use incentives to inspire individuals to implement their own
catchment systems?
For more
information on Tucson’s rainwater catchment ordinance, go to: http://www.tucsonaz.gov/water/harvesting.htm.