Peeling back the Pavement - POLIS Water Sustainability Project

Department of Transportation and Public Works has, since 2005, been installing
RWH tanks in all new schools in regions with water quality and/or quantity issues. 34
RWH decreases the pressure placed on municipal potable water infrastructure to
meet all of a community’s water needs. This deferral creates savings in both energy
use and greenhouse gas emissions from lower rates of pumping and treatment, 35
and financial benefits in the long term from reduced infrastructure capital, operations,
and maintenance costs. Researchers in Australia found that using rainwater
tanks in dryer regions, such as the Lower Hunter and Central Coast, deferred drinking
water infrastructure needs by 28 to 100 years, with projected savings of $78 million
in Lower Hunter and $47 million in the Central Coast. The study found that wetter
areas, like Sydney or Brisbane, yielded even greater water savings. 36 In a Rainwater
City, uptake can be promoted by helping property owners reduce the costs associated
with installing RWH systems through incentives such as rebate programs.
The key to harnessing the full
benefits of RWH in a Rainwater
Provincial/territorial policy
City is to diversify applications and endorsement and guidelines
end uses across sectors so that
provide needed support to
rainwater storage tanks can be
“early adopter” communities
constantly drawn down, minimizing
dependence on municipal supply. in regions that are attempting
Separating drinking water supply to overcome these regulatory
from other water uses may facilitate
barriers.
this. A 2007 report from the British
Royal Society of Chemistry called for a separate water supply system for drinking
water pipes as an ideal system for Great Britain. 37
Most major cities in Australia, driven by years of drought, require that all new
construction be fitted with “purple pipe” systems (dual pipe connections that
deliver recycled, non-potable water to properties) in order to meet water needs.
In Canada, although rainwater can be immediately mandated for all outdoor
non-potable uses (including use on city-owned properties and golf courses),
builders and local governments still face a number of regulatory barriers to
implementing RWH across a broad spectrum of end uses. National, provincial,
and territorial building and plumbing codes lack clear differentiation between
greywater, non-potable water, and rainwater. Liability concerns prevent innovative
local governments from mandating purple pipes in new construction and
redevelopment, and from mandating the widespread use of RWH systems inside
homes and commercial buildings. Overcoming code restrictions is a crucial step to
using rain as a viable source of water. Provincial/territorial policy endorsement and
guidelines provide needed support to “early adopter” communities in regions that
are attempting to overcome these regulatory barriers.
39