Houston as a Model City: Meeting the challenges of an environmental crisis
The Future of Water
by Vicki Wolf, April 2006
Today the City of Houston has plenty of water and has won awards for its water quality accomplished through water treatment plants, according to city officials. Jeff Taylor, Houston’s Public Works director, says the emphasis is on water quality rather than water supply in Houston because the city receives about 50 inches of rainfall a year and has a 30 to 50 year supply. However, Jim Adams, general manager of the San Jacinto Water Authority and chair of Region H Water Planning Group (Region H includes Houston), says by 2060, Houston will require three billion gallons of water a year. “We are going to have to reuse water and we are going to have to conserve,” says Adams. “Water is not as plentiful as it use to be.”
Rives Taylor, research scientist with Houston Advanced Research Center’s Energy and Buildings Solutions Group and sustainability leader for Gensler Architecture, says these forecasts are optimistic as the population of Texas grows and droughts are more common. He believes in three years we will have concerns. The water that Houston uses includes the Trinity River and the San Jacinto River, both downstream from areas with rapidly growing populations. Also, Texas is experiencing the longest dry spell since the drought of record in the 1950s with low precipitation levels forecast through this summer. Global warming may bring more droughts in the future.
Also, use of ground water, pumping water from aquifers below the ground, is causing the land to sink. To prevent further subsidence, Houston is moving from ground water as the predominant source of water to surface water – lakes and reservoirs storing water that comes from rivers.
One of the reasons city officials are comfortable with Houston’s water supply is its rights to 1.3 billion gallons of water per day that flow down the Trinity River after use in the Dallas/Ft. Worth metroplex (DFW). “One advantage is that Houston is at the base of the Trinity River,” Jeff Taylor says. “We benefit anytime DFW imports water into the Trinity and discharges it downstream. We are drinking their wastewater, and the lower Trinity water supply has increased over time.” According to Taylor, treatment of the wastewater makes it “really clean.”
Bill White, Houston’s mayor, says the efficient use of water, is second only to improving air quality for making life in the city more sustainable. “We are a water-rich region, compared to other parts of the country,” White says. “We can do more to use water efficiently. I don’t mean mandates and quotas,” he adds. “I would like to see us have more native plants used in landscaping.” He also says the city can find out what other cities that have encountered water issues are doing. He advocates appliances that use less water. “Less waste water means fewer water treatment plants.”
“We will have enough water if we conserve, change our lifestyles and change our practices of wasting water,” Adams says. He presented the Region H updated five-year water plan to the Texas Water Development Board on April 18. The plan calls for reusing wastewater for irrigation of landscapes and industrial processes and other conservation measures.
Water conservation is essential to sustainability for any large city. Questions to ask when working toward water conservation are: How can the city capture more water and prevent runoff? Where can water be reused? Where is water being used needlessly?
Capturing rainwater and storing it in cisterns is an effective way to reduce runoff and conserve the public supply. Rainwater without chemical treatment can be safely used for flushing toilets and washing clothes. It can be used for drinking when properly treated.
Considering that up to 60 percent of city water is used for landscaping, moving toward sustainability requires collecting and using rainwater for landscape and garden irrigation. Selecting native and adapted plants, and designing landscape and gardens to capture water and prevent runoff also help save water. Garden beds, shrubs and mulching are better conservation choices than growing grasses.
Planting vegetation similar to the diverse prairies and forests that covered Houston before it was paved over for development can be planted across the city, even on rooftops, to help cool the city and prevent runoff during heavy rains.
Grey water – water that has been used for washing clothes and dishes or bathing – can be reused for landscape irrigation. Condensate from the cooling towers of large buildings also can be reused. Rives Taylor says, “We don’t touch 85 to 90 percent of water that goes through residential and public buildings, so why not use grey water and rainwater for these situations.” He says rainwater sometimes is preferred in mechanical systems because it does not contain as many chemicals as municipal water.
Another way to save water and provide distribution systems for grey water and rainwater is to replace water heating systems that require plumbing and storage with on-demand systems. “Traditional systems in large buildings have boiler pipes all over the place,” says Taylor. “On-demand water heating, located close to the source, requires no hot water piping. Those pipes can be used to distribute grey water or rainwater.” To conserve water and energy, the UTHSC School of Nursing and Student Community Center was designed for this method of water heating, as well as grey water and rainwater use.
The amount of water used for flushing urine today is excessive and not necessary. Rives Taylor says installing one waterless urinal in a large public building, such as an airport, can save 40,000 gallons of water in one year. The School of Nursing, LEED certified for its sustainability features, currently uses waterless urinals. Learning to install and maintain the urinals properly is technically simple and essential in successfully replacing flush toilets. Low-water flush toilets can save three to four gallons of water with every flush.
Education can help facilitate needed change. The City of Houston is implementing water conservation education in schools. These programs are expected to reach more than 10,000 students per year. Also, the city provides speakers and materials to schools, local businesses, civic organizations, homeowners’ associations, and city representatives attend more than 50 local trade shows, health fairs and community events to spread the water conservation message.
Cath Conlon, creator of Blackwood Land Trust Institute, a 23-acre permaculture farm, located 44 miles west of Houston on Highway 290, is working with other designers to create a water education center within the Northeast Water Purification Plant. The center features information on the cycle of water, two water harvesting tanks and gardens appropriate for the climate. Information presented at the center encourages people to harvest water and to plant for cooling. “We are hoping to impact children who come through to have better respect for water and to use it more responsibly,” Conlon says.
“Water equals life,” she adds. “If we don’t have water, we don’t have life.”
For more information:
A rainwater harvesting manual is available at: www.twdb.state.tx.us/publications/reports/RainHarv.pdf
For water-wise landscaping information visit: www.twdb.state.tx.us/assistance/conservation/Municipal/Outdoor.asp
The University of Texas Health Sciences Center School at Houston School of Public Health Green Roofing Project.
Find information on waterless urinals at www.facilitiesnet.com/ms/feb04/feb04construction.shtml
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