Landscape consultant briefs Universal City Council on xeriscaping, rainwater harvesting

Mark Peterson, a landscape consultant and former Texas Forest Service and San Antonio Water System (SAWS) employee, told the Universal City City Council on March 4 that xeriscaping can cut household water use if it is applied correctly and that rainwater harvesting has practical limits without sufficient rainfall.

Peterson told the council and staff that the commonly cited definition of xeriscape can be condensed to three principles: limit turf to no more than 50% of a yard; use appropriate, preferably native drought-tolerant plants; and apply appropriate irrigation. “It does not mean rocks. It does not mean cactus. And it certainly does not mean landscape cloth,” Peterson said.

Why it matters: Council members and staff raised xeriscaping and alternative-water strategies as tools to reduce residential water demand and to guide future landscape policy. Peterson’s briefing identified practical constraints — including local rules on rainwater storage and the variability of rainfall — that could affect whether households see measurable savings.

Peterson gave several practical figures during the presentation. He said properly designed landscapes often require only about a half- to three-quarters-inch of irrigation for many weeks of the year, and that a single week’s irrigation at that rate can use roughly 1,400 to 2,200 gallons. He also said a typical four-person household’s annual water use is about one acre-foot, roughly 325,000 gallons.

On rainwater harvesting, Peterson said systems sized from historical averages can require large tanks to meaningfully replace potable water use; he said Universal City currently limits rainwater tanks to about 5,000 gallons under existing local regulations. “Just imagine a 22,000-gallon tank in the back of somebody’s yard,” he said, noting that those tanks are impractical for many homeowners.

Peterson also discussed greywater (laundry, shower and non-food sinks) as part of a broader “alternative water” category, and said state and local rules typically require systems not to create a public nuisance or discharge off-site. He mentioned that the Texas Commission on Environmental Quality allows limited reuse for certain landscape and non-food uses, but cautioned about issues such as soap chemistry and debris that can clog systems.

Council members asked how compliance and inspection might work if the city offered incentives or programs; Peterson described San Antonio’s past coupon-and-inspection approach, which used pre-approval photos and a final on-site check before issuing nursery coupons. He offered to provide additional materials and to follow up with staff.

Peterson and staff said additional educational resources are available on GardenStyle SanAntonio (the SAWS outreach site) and through local nurseries that specialize in native and pollinator-friendly plants.

Council members and staff did not take formal action during the presentation; Peterson’s talk was for information and possible follow-up.