Water Conservation


lauren ross glenrose engineering


Liquid Carbon

Danger sign with faucet with electric volt coming out About 4% of all the electricity in the U.S. is dedicated to water and wastewater processing and pipeline transport for public and private utilities.  This translates into 4% of U.S. carbon emissions produced from electric production.  Moreover, this estimate is far from complete.  It probably underestimates the considerable energy needed to pump and transport water used for agricultural purposes, and excludes the vast amount of embodied energy it took to build the country’s water treatment plants, reservoirs, dams, pipelines, irrigation canals, and agricultural water pumps.

On the surface, Austin’s water utility buys almost all of its electric supply from wind power.  However, the Texas (ERCOT) system, which Austin depends on to balance its intermittent renewables, received only 15% of its supply from renewable energy in 2016.  Almost 3/4 of ERCOT electricity that year was generated from carbon emitting fuels.

Five Ways to Save Water (and Carbon)

1. Check for Leaks

Water leaks do not make noise, but they are not silent either.  They scream money for higher water bills, and from property damage if the leaks are in the building structure.

Once a year, remove the lid that covers your water meter.  (They can be heavy; the handle of a caulking gun is a good make-shift tool.)

Mark the meter needle with a colored pencil or felt-tip pen and wait for 10 minutes to see if the needle moves while using no water in your house.  If it does, there is a serious possibility of a leak that needs repair.  Another leak detection method for homes is to put food dye in toilet tanks.  If the color leaks into the bowl prior to flushing, the flapper is failing and needs replacement.

2. Managing or Changing Your Lawns

About a third of all water in single-family homes in Texas  is used to irrigate landscapes.  Key strategies can greatly reduce outdoor water use.

A. Good Soil – Adding compost and good soil increases the moisture retention, allowing turf, plants, and trees to go longer without watering. This will also provide nutrients to encourage plant growth.

During home construction, much or all of the original topsoil is removed. What remains is often compacted by heavy equipment. Many builders simply add a couple inches of soil and then attempt to establish a lawn. Turf on these poorly designed lawns becomes reliant on frequent watering, chemical fertilizers, and pesticides.

Adding a half-inch of soil a year to existing lawns can minimize expenses while allowing the grass and some plants to adapt in place. While the goal is to get to 6 to 18 inches in soil depth, too much soil at once can kill the lawn.

Austin is fortunate to have a number of good retail outlets and manufacturers of soil products and amendments to assist plants organically. Though many retailers carry these products in small amounts, the retailers listed below generally have the best variety at volume prices.

These retailers sell compost rated by the U.S. Composting Council for its Seal of Testing and Assurance (STA). The STA rating verifies that pathogens and heavy metals do not exceed certain levels. It also gives specifications for pH, nutrients, stability, maturity, percent of organic matter, and moisture content.

It is more cost effective to add the right soil and soil depth at the beginning when the home is constructed and the lawn is created. Since the landscapers will be on site anyway, doing it right the first time will save money.

Austin Landscape Supplies – Georgetown 5317 N. IH 35 (512) 930-2311
Austin Wood Recycling – Austin 9201 FM 812 (512) 259-7430
Austin Wood Recycling – Cedar Park 3875 E. Whitestone (512) 259-7430
Countryside Nursery & Landscape 13292 Pond Springs Road (512) 249-0100
Enchanted Rock and Landscape Supplies 11892 Old FM 2243 (512) 260-2747
Garden-Ville – Creedmoor 3606 FM 1327 (512) 329-4900
Garden-Ville – San Marcos 2212 Old Ranch Road 12 (512) 754-0060
Garden-Ville – Georgetown 250 W.L. Walden Road (512) 930-8282
Garden-Ville – Bee Cave 4001 Ranch Rd. 620 S. (512) 219-5311
Geogrowers – Austin 12002 Highway 290 W. (512) 288-4405
GreenThumb Compost – Austin P.O. Box 41539, 78704 (512) 369-0998
JV Dirt + Loam – Austin (Not all batches certified) NA (512) 927-1977
Natural Gardener – Austin 8648 Old Bee Cave Road (512) 288-6113
Organics By Gosh – Austin 13602 FM 969 (512) 276-1211
Rock N Dirt Yard 8401 S. 1st Street (512) 461-7607
Whittlesey Landscape Supplies – Austin 629 Dalton Lane (512) 385-0732
Whittlesey Landscape Supplies – Round Rock 3219 IH 35 S. (512) 989-7625


B. Drought-Tolerant Plants – Trees, plants, and turf native to Central Texas will often survive better without water than plants native to other U.S. regions and other countries.  Austin’s water conservation program began promoting “xeriscape” low-water use and native plants over 30 years ago, and they are incredibly easy to find at most nurseries and garden stores.

Low-water use plants for this region can be researched through the LBJ Wildflower Web site: wildflower.org/plants

Another great resource to plan xeriscape is the City of Austin Watershed Protection Grow Green Web site: austintexas.gov/department/grow-green-resources.  A lot of information is downloadable; hard copies can also be requested by mail.

A note of caution: replacing lawns and plants with rocks and rock gardens is not the most environmental option.  While this will save water, it also creates other problems.  Hardscape retains heat, adding to the heat island effect that makes urban areas hotter than the surrounding countryside.  To the extent that these hardscapes are close to buildings, they can be a direct cause of increased air conditioning load.

Rock gardens can also be difficult to maintain.  To keep a uniform appearance, undesired grass and plants must constantly be removed, often tempting homeowners to use dangerous herbicides.

C. Grass – Some grasses are more drought resistant than others.  Few species can survive with no irrigation at all.  A study done by the Williamson County Agricultural Extension Service, conducted between 1997–2000, showed only 4 grass species sold in Central Texas could survive without irrigation after 3 years.

These were: Nebraska 909 and Top Gun Buffalo Grass; Floratam St. Augustine; and Jamur Zoysia.  This is not to say that your grass will look lush after 3 years without enough water, but in a harsh drought, (most) people prefer to use essential water for drinking instead of watering their lawns.

Replacing an entire lawn at once can be expensive.  Better strategies include overseeding bare patches of lawn, and preferably, establishing the right lawn to begin with for a new home.

D. Irrigation Systems and Devices  – As a rule, owners of homes with automatic irrigation systems use more water than those using a hose and sprinkler.  Many do not know how to properly adjust the controllers.  Others may leave the system on even after it has rained.

Bearing this in mind, several irrigation systems and retrofits exist to make automatic systems considerably more efficient.  Some devices and technologies might work in concert with each other, though there will be diminishing savings for each new measure added.

Rain Shut-off Devices – These devices override irrigation controllers when significant rain occurs.

Pressure Regulating Valves (PRVs) – PRVs are inserted into a customer’s plumbing to prevent misting and evaporation losses in irrigation systems.  This can occur when high water pressure sprays water at greater force than sprinkler heads are designed for.  By one estimate, they can save as much as 9% of the water in an average Austin home.  Though required by the Austin building code for irrigation systems in new homes with high water pressure, most older systems do not have them.

Efficient Sprinkler Heads – Conventional sprinkler heads often have uneven “Distribution Uniformity” when they are broadcasting water to the zone they serve, leading to excess irrigation.  “Multi-stream, Multi-Trajectory Rotating” (MSMTR) heads compensate for this.  Studies have shown about a 10% savings compared to conventional equipment.

Drip “Capillary” Irrigation – Drip irrigation for turf applies water directly to the root zone below the soil, and is virtually immune to direct water losses from evaporation and wind spray.

E. Amount and Frequency of Water – Grass does not need as much water as many homeowners use.  In Austin, mandatory watering days are spaced 3 or 4 days apart.  Apply about 1 inch (as measured in a container near the irrigation system) at a time.  In shallow clay soils, it is best to water small amounts several times to allow water to percolate.  Otherwise, water can be lost as runoff.

Austin’s ordinary (non-drought) schedule for Residential watering (4 units per building or less) is easy to follow.  Watering cannot take place between 10 AM and 7 PM.

Exemptions (any time of day):

  Drip irrigation, hand-held hose, or refillable container, vegetable gardens with a soaker hose or soaker tape.

  Trees using a bladder bag, soaker hose, soaker tape, or automatic tree bubbler in the drip-line of the canopy.

  Watering with rain water, gray water, or other auxiliary water

Customers violating this schedule repeatedly may face civil fines.

3. Efficient Toilets and Fixtures

Depending on the age and tank size, toilets can use anywhere from 10 to 40% of the indoor water use in an average Austin home.  While the typical toilet of the 1960s used 5 to 7 gallons per flush, today, the best conventional “single-flush models use between 0.80 and 1.06 gallons.  The advent of dual flush toilets, that allow less water to be used to remove liquid waste, has shown even lower consumption when averaged over time.

Maximum Performance (MaP) Testing is run by a non-profit organization that rates performance of most major toilet manufacturers to certify that their units save water and still remove large volumes of solid waste.  The minimum standard is 350 grams per flush, which is adequate for the vast majority of uses. Paying more for units above this base performance level is generally not necessary, though there are several hundred units on the market that greatly exceed this.

There are other qualities to look for in a new unit.  One of them is sound.  Consumers are advised to be cautious of pressure-assisted models that use a combination of water and compressed air to propel water.  These are extremely loud and disturbing.  Another consideration is how clean the bowl stays after washdown. Consumer Reports magazine is a good source to compare quality of competing models.

Showers consume about 17% of domestic indoor water use.  In the early 1990s, showerheads could use as much as 5.5 gallons per minute.  National standards in 2012 mandate units that consume no more than 2.5 gallons per minute.  The WaterSense rating program recommends water-conserving fixtures using no more than 1.5 gallons/minute.

Indoor faucets consume about 15% of domestic indoor water use.  National standards for bathroom sink faucets in 2012 limit consumption to no more than 2.2 gallons per minute.  WaterSense rated fixtures reduce use to 1.0-1.5 gallons per minute, a savings of 32 to 55%.  Inexpensive aerators can reduce flow to as little as 0.5 gallons per minute.

For more information and listed products for MaP-and WaterSense-rated toilets, showerheads, and faucets, see the Web sites: map-testing.com and epa.gov/watersense.

4. Efficient Clothes Washers

In 2009, about 82% of U.S. homes used automatic clothes washers.  The average unit cleans almost 400 loads of laundry a year.  An older, inefficient home clothes washer can use about 12.2 thousand gallons a year, equivalent to 16% of an average Austin home’s water use in 2016.

Top-loading High Efficiency (HE) washers achieve back-and-forth motion with wobbling plates, wheels, or disks.  Front loading HE washers repeatedly tumble clothes through water at the bottom of the drum.  Though front-loading clothes washers generally save more energy and water, efficient top-loading units do exist.

Water in these appliances is rated by an Integrated Water Factor (IWF): the number of gallons used per load divided by the cubic feet of capacity of the washer.  The first federal standard was only imposed in 2011.  However clothes washers today can reduce water use by as much as 73% compared to this standard.



The IMEF has also changed dramatically, with reductions of as much as 74% compared to requirements in 2004.Energy use is rated as an Integrated Modified Energy Factor (IMEF), which adds all energy used in the washing cycle, including the electricity for machine use, water heating, and drying, as well as “stand-by” losses from electronic controls that never turn off.  Energy uses in the washing cycle interact.  Cutting back on water use cuts back on water heating.  Increased spinning to remove more moisture from clothes cuts down on heat needed for clothes drying.


• Cold-water detergents and clothes lines eliminate almost all energy use in the wash cycle.  With an inefficient machine, roughly 80% of the energy use comes from water heating and fabric drying when natural gas is used for fuel.  When electricity is used for drying, it is about 90%.Other Considerations

• Buy the right kind of detergent for HE machines.  Conventional detergents create more suds.  In HE machines, the excess suds may prevent water from properly rinsing clothes and may impede tumbling.

• HE detergents have a logo on the bottle designating they are for HE washers.  Some detergents state they are “HE Compatible,” which is not always the same thing.  Experiment with such products first to make sure they do not cause a problem.

• Front-loading washers have been shown to reduce detergent use up to 25%, in addition to running quieter and being gentler on fabrics (which lengthens their useful life).

To view lists of efficient clothes washers, see the Web sites for the Consortium for Energy Efficiency (cee1.org), and ENERGY STAR (energystar.gov).

5. Rainwater Harvesting

In Central Texas, if you have a roof area of 2,500 square feet and a yearly average rainfall of 32 inches, you can collect almost 45,000 gallons of rainwater in a typical year.  This can meet most or all of the annual indoor needs of a water-conserving household of 3 to 4 people for a year.

Among the many benefits of rainwater use are: water supplies without treatment chemicals (chlorine, fluoride) or pollutants; elimination of scale in pipes and appliances (lengthening life and maintaining energy efficiency); and self-sufficiency, including availability if emergencies curtail normal water service.  Unfortunately, in almost all residential installations, rainwater cannot compete economically against municipal water systems.  They can, however, compete with private wells.

Numerous hardware and specialty stores sell rainwater barrels, tanks, pressurization pumps, and other accessories.  Professionals that deal with issues of pressurization, water filtration and purity, and proper connection to plumbing systems are harder to come by.  A list of these installers is provided here, though consumers should get competitive bids and seek references.

Other Rainwater Resources

Texas Manual on Rainwater Harvesting, Third Edition, July 2005.  Online  at www.twdb.texas.gov/publications/brochures/conservation/doc/RainwaterHarvestingManual_3rdedition.pdf

City of Austin rainwater rebate program: austintexas.gov/department/water-conservation

innovative water solutions lauren ross glenrose engineering


All Things Rainwater P.O. Box 2224 Wimberley, 78676 (512) 826-0653 All sizes & types
Blue Gold Engineering 3005 S. Lamar, D109, #144 Austin, TX 78704 (512) 944-0677 Design/build rain/graywater; home & business
Bowerbird Construction P.O. Box 1141 Dripping Springs, 78620 (512) 858-5395 20,000-100,000; ferrocement
Bright Leaf P.O. Box 300012 Austin, 78703 (512) 371-7220 500 gallons and up; all materials
Dick Peterson 3451 Mayfield Ranch, #306 Round Rock, 78681 (512) 922-3326 System design, consultation & instruction
Flores-Shepard LLC 3904 Manchaca Rd. Austin, 78704 (512) 775-6060 100 up to 5,000 gallons; plastic; drip irrigation
Harvest Rain 2770 Hwy. 290 W. Dripping Springs, 78620 (512) 689-4906 All materials; 2,500-60,000 gal.
Harvested Rain Solutions 11183 Circle Dr., Suite D Austin, 78736 (877) 693-2166 5-130,000 gal. irrigation systems; all materials
Hydro Catch 825 Johns Road, #822 Boerne, TX 78006 (512) 784-2513 Designs 500-20,000 gallon systems; all types
Innovative Water Solutions 501 W. Powell, Suite 206 Austin, 78753 (512) 490-0932 All types of materials
Lakota Water Company 10006 Longhorn Skwy. Dripping Springs, 78620 (877) 652-5682 Up to & above 100,000 gallons; all materials
Longhorn Water Treatment P.O. Box 726 Leander, 78646 (512) 260-5900 55-25,000 gallon; all types
Mark Wieland, Master Plumber P.O. Box 2743 Austin, 78768 (512) 626-2547 up to 20,000 gallons, fiberglass
Native Constuction 201 Cole Street Austin, 78737 (855) 253-6284 20,000-30,000; metal
Pinnacle Water Tanks 1704 Colt Circle Marble Falls, TX 78654 (512) 755-4553 1,500-65,000 gallons; metal
Rain Man Waterworks 2263 Red Corral Ranch Rd. Wimberley 78676 (512) 351-5150 Turnkey rainwater for home and landscape
Rain Harvest Resources 1019 C.R. 323 Liberty Hill, 78642 (512) 864-4226 Up to 65,000 gallons; all materials
Rainwater Works P.O. Box 1429 Burnet, 78611 (512) 277 0096 5-65,000 gal.; residential, commercial, ranch
Southern Exposure 1483 CR 311 McDade, 78650 (512) 663-9538 3,000-15,000 gallons; all materials
Steady Rain Irrigation 12420 Turtleback Ln. Austin, 78727 (512) 589-0833 3,000 gallons or larger; plastic tanks
Sustainable Homesteads 8607 Swanson Lane Austin, 78748 (512) 282-6629 Up to 40,000 gallons; all materials
Tall Drink Rainwater Harvesting 20310 Haystack Cove Spicewood, 78669 (512) 769-1254 6,000 gallons and up; metal and plastic
Texas Metal Tanks 16299 Fitzhugh Rd., Building E Dripping Springs, 78620 (512) 565-0875 90 to 5,000 gal.; metal & cedar
Texas Native Rainwater 3600 Elder Hill Rd. Driftwood, 78619 (512) 466-2898 Res. irrigation up to 20,000 gal.; graywater


The Leading Edge

A New Kind of Clothes Washer

Xeros washing machine with tiny bead magnified to show relative size next to a thumb

Courtesy Xeros


Throughout recorded history, clothes washing has relied on 3 tried and tested strategies to remove dirt and stains: wash water as solvent (preferably hot water); chemical agents mixed with the water (detergents, soaps, and bleaches); and agitation (scrubbing, hand-beating, or mechanical motion).  Today’s standard clothes washers can integrate all 3 options in a convenient box.

A British company, Xeros, has developed a new spin (no pun intended) on clothes washing that mixes tiny plastic beads with a small amount of water to enhance agitation to clean clothes.  The beads remove dirt, stains, stray dyes from fabric, and chemicals and smoke particles (important in cleaning protective gear for fire fighters).  Xeros states that its washers can reduce water use 70 to 80%, energy used to heat water by 50 to 100%, and detergent use by 50%.   

Each full laundry load will use 1.3 million beads injected with water, which are constantly hitting the fabrics as the machine’s drum tumbles.  With careful drum cycling and vacuum removal, almost all of the beads are removed at the end of the washing period for reuse.  The few beads that are left (as few as 20) are usually removed through other laundry processes such as drying and folding.  The beads can last 500 to 1,000 cycles before they are recycled.

Xeros uses a proprietary detergent that is hypoallegenic and fragrance free.  Since the process uses less agitation and detergent, fabrics generally last longer.

The company estimates its machines carry a premium of $7,000 (which includes monthly maintenance).  Considering average U.S. utility and detergent costs, they can pay back this premium in 2 years.  To date, the machines are only sold for commercial use (professional laundries, hotels, hospitals), though a residential machine is in development.

Xeros U.S. Office 1 (844) 207-1099

250 Commercial St #4002a, Manchester, NH 03101


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