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Modern rainwater harvesting efforts evolve beyond backyard barrels Posted on May 27, 2020

Austin Central Library. Photo courtesy of Austin Public Library.

It’s not uncommon to see plastic rain barrels sitting next to homes waiting for the next rainfall to send water flowing into a downspout. Collecting and storing rainwater can provide water for a variety of residential uses, lower your water bill, and reduce demand on both surface and groundwater supplies. As a general rule of thumb, for every inch of rain that falls on a 2,000-square-foot roof, about 1,000 gallons of water can be collected. 

Much of the growth in rainwater harvesting in Texas over the last few decades has been in small-scale, residential rainwater harvesting systems. For large-scale water supply needs, Texas businesses and institutions have traditionally relied primarily on centralized water distribution systems that haven’t included large-scale rainwater catchment techniques. 

But as the state continues to grow at a rapid pace and demand on our surface and groundwater supplies increases, the role that rainwater harvesting can play in commercial- and community-scale projects and facilities is evolving statewide. Across Texas, schools, libraries, businesses, and utilities are implementing innovative rainwater harvesting methods to divert and store water from the sky on a big scale.

Commercial-scale innovation

From Austin to Amarillo, building planners are taking into account water conservation when designing new facilities. The Austin Central Library garnered national attention for its rainwater capture, condensate reuse, and reclaimed water strategies. The library collects rainwater and the water dripping off of air conditioning equipment and uses that water for flushing toilets and urinals inside. 

“The rainwater/condensate collection and reuse provide an approximately 85 percent offset of potable water use,” said Lee Butler, the building services manager at the library. “So, 85 percent of the water we use is for flushing toilets and irrigation. We only use potable [water] for sinks, water fountains, ice machines, and the café.” 

Fifty miles southwest of Austin, construction crews are working on an innovative primary school campus that will incorporate “One Water” strategies. The Wimberley ISD campus will use 90 percent less water than a typical school of its size. Campus construction plans include rainwater and HVAC condensate collection, together with wastewater treatment and reuse. 

According to a Wimberley ISD press release, “the design for the school acknowledges the importance of protecting Jacob’s Well, Blue Hole, and the Trinity Aquifer by reducing groundwater consumption by 90 percent of what a traditional school this size would use.”

While most large-scale rainwater harvesting systems utilize a large above-ground tank, FirstBank Southwest Amarillo decided to look downward. At the Western Banking Center in Amarillo, the parking lot is the water collection system. Permeable pavers allow water to flow through gravel backfill and into a perforated pipe that carries water to an underground tank.

FirstBank Southwest President and CEO Andy Marshall said the innovative system allows nature to provide water resources and demonstrates the bank’s commitment to doing the right thing. “We felt that our place in the Texas Panhandle and the many communities we serve made designing and creating a sustainable water source an economic and ecological imperative,” he stated.

Community-wide strategies

Rainwater harvesting has found a place in government policy as well. The State of Texas has long promoted the use of rainwater harvesting to conserve water. Texas Tax Code allows for a state sales tax exemption on rainwater harvesting equipment, and Texas Property Code prevents a homeowner’s association from prohibiting the use of rainwater harvesting systems.

Utilities are also implementing programs to encourage the use of rainwater harvesting systems because these systems can decrease the demand on a utility’s water supply. Rainwater harvesting systems also impact stormwater flow because water that would traditionally flow into stormwater drains is collected on-site. Utilities promote rainwater harvesting at residential, commercial, industrial, and educational facilities through incentives such as discounts for rain barrels or rebates for water storage tanks.

The New Braunfels Utilities offers a rebate of $0.50 per gallon of storage toward the purchase of barrels or cisterns for a maximum rebate of $250, as a credit on customers’ accounts. In nearby San Antonio, the San Antonio Water System’s RainSaver Umbrella Program also offers rain barrel and cistern rebates, as well as tips on building rain gardens and coupons for rain barrels. 

Texas Rain Catcher Awards 

The Texas Water Development Board (TWDB) has supported the implementation of rainwater harvesting systems in many ways, including through the release of The Texas Manual on Rainwater Harvesting in 2005. In 2007, the TWDB established the Texas Rain Catcher Award, a competition open to all individuals, companies, organizations, municipalities, and other local and state governmental entities in Texas. The award recognizes entities and individuals in the rainwater harvesting community and beyond and establishes award recipients as dedicated water conservation leaders in Texas.

The annual application deadline is June 30. 

For more information about rainwater harvesting, visit the TWDB website.


This article is posted in Conservation / Rainwater Harvesting .