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Austin's
Zilker Park Showcases Rainwater Harvesting
by Karen Stewart, City of Austin
Zilker
Park, in the heart of downtown Austin, is set to become the
prime rainwater harvesting demonstration site for the City of
Austin.
The
recently completed system is ready for public viewing and is
meant to educate visitors in the forgotten benefits of rainwater.
For
centuries people relied on rainwater harvesting to supply water
for household, landscape, livestock, and agricultural uses.
However, with the development of large, reliable water treatment
and distribution systems and more affordable well drilling equipment,
rainwater harvesting systems have been all but forgotten, even
though they offer a source of pure, soft, low sodium water.
A
renewed interest in this time-honored approach has emerged in
Texas and elsewhere due to:
-
the
escalating environmental and economic costs of providing water
by centralized water systems or by well drilling;
-
the
human and plant health benefits of rainwater; and
-
the
potential cost savings associated with rainwater collection
systems.
The
City of Austin has been promoting water conservation for several
years by selling rain barrels, giving rebates for larger systems,
and conducting tours of commercial and residential rainwater
harvesting systems. The rainwater harvesting system at Zilker
Botanical Garden, built by volunteer Master Gardeners and funded
by the City's Water Conservation Program, provides a very visible,
permanent demonstration.
Zilker
Park Schematic: Click on Image for Enlargement
The
tanks at the Zilker site have been selected to show a variety
of styles, types, and prices available:
-
The 2000-gallon gray tank is made of fiberglass, a material
sturdy enough to be used for larger tanks. The cost is twice
that of the poly tanks, with a lifespan greater than 20 years.
-
The black and green polyethylene (or "poly") tanks
hold 2500 gallons each, with an expected lifespan of over
20 years. Poly tanks must be colored or painted to prevent
algae growing inside the tank. These tanks come in a large
variety of sizes to fit into any home or landscape site. Polyethylene
tanks have significantly reduced the price of small to medium
size systems.
-
Metal farm tanks, like the 3100-gallon tank at Zilker, are
often selected for their old-fashioned charm. Typical galvanized
tanks rust out, and have a limited life span. This tank has
a geotextile pre-liner to protect the seams and metal from
condensation and moisture. The tank is then lined with a 25
mil rubber "bladder" or flexible membrane lining.
The lifespan of this tank is more than 20 years, and the cost
is roughly four times that of the poly tanks.
The
fiberglass and poly tanks can be painted, resurfaced with stone,
stucco or wood trim to fit into any home or landscape.
Greenbuilder: Dick Peterson
gives a tour of the system. HarvestH2o photo
When considering a home rainwater storage system, size matters.
Rainwater tank and storage size needs to relate to the size of
the roof and the amount of landscape to be watered. It typically
takes about 30,000 gallons of water to irrigate a typical home
lawn/landscape with one inch of water. In other words, one or
two waterings would empty most small tanks. So if building a system,
make sure to build it big enough to handle your watering needs.
Rainwater
harvesting is not always an economical choice when compared to
potable water provided by most cities. However, most people choose
to collect rainwater for reasons other than cost savings.
Rainwater
harvesting:
-
is environmentally friendly
-
is better for plants
-
prevents soil erosion by reducing rainfall runoff
-
can be self-sufficient
-
conserves energy from potable water processes, and
- fosters
a greater appreciation of nature.
The
rainwater harvesting system at Zilker Botanical Gardens will benefit
not only garden plants, but will help homeowners understand whether
or not a rainwater harvesting system is right for them, and which
features and types of materials they prefer.
HarvestH2o photo
 Zilker Park's older tanks being updated.
They
are used to feed the greenhouses in the back of the park.
Zilker
Park has been using rainwater harvesting for years to assist with
watering their lush gardens. The tanks and equipment have not
been visible or accessible to the public but have been vital to
the nurturing of new plants. With these new tanks the public can
visit and learn more about rainwater harvesting.
Zilker
Park is located at 2220 Barton Springs Rd, in the heart of downtown
Austin and is open 7 days a week.
Related Links:
History of Rainwater Harvesting at Zilker Park
Reprinted with permission from the WaterWise Newsletter, a publication of the Austin Water Utility’s Conservation Program
Photos, where noted, are Copyright © 2005 HarvestH2o. All rights reserved. |
