Frisco Weather Station. Image: Frisco Public Works

By Bill Sullivan

You’ve probably seen it somewhere in your neighborhood: A sprinkler system going full blast, watering the yard, sidewalk and street, wasting untold gallons and taxing water districts and reservoirs in the process.

Thanks to some creative thinking by the City of Frisco, such scenes should become less common. By mining data from its own weather station, Frisco Public Works can provide residents with real and practical advice on how much they need to water to keep yards healthy and green, even in the hottest months.

Hint: It’s a lot less than you may think.

“What we found since we installed this weather station is that, for a large portion of the 52 weeks of the year, we recommend no watering at all,” says Melody Emadiazar, the city’s Water Education Coordinator. “That’s information we wouldn’t have known if we didn’t have this weather station.”

Frisco's Weather Station collects data that is used to produce irrigation recommendations for homeowners. Image: Frisco Public Works

The evapotranspiration (or ET) weather station, which is set adjacent to one of the city’s four elevated storage tanks, was put into operation in November of 2007 at a cost of about $15,000. It measures five factors: wind speed, solar radiation, temperature, humidity and rainfall. Real-time data is transmitted every five minutes by radio signal. The city uploads the data to an FTP site and uses it to come up with the weekly watering recommendations posted on its web site and distributed to e-mail subscribers.

“When you know all those elements, you know essentially whether you do or don’t need to water,” Emadiazar says.

The station helps make Frisco residents some of the best informed in the North Texas region. In the Dallas-Fort Worth area, only Irving and Dallas have made similar investments in technology that can help conserve our most precious resource. (Previously, Frisco used information from the Irving station.)

Essentially, the data allows the city to measure rainfall — taking the average of the readings of four gauges placed at the four elevated storage tanks within the city — while subtracting water loss due to evapotranspiration (the amount of moisture lost to the atmosphere through evaporation and plant transpiration). Using formulas developed by the Texas A&M Irrigation Technology Center, the city is able to factor in the kinds of plant material common for the area and the growth factor (more in warmer months, less in the winter) into an “ET rate.”

That ET rate, minus the amount of rainfall measured each week, produces the figure for how much irrigation a yard should require. When rainfall exceeds the ET rate, it’s time to give the sprinkler system a rest.

“Your sprinkler system is only for supplemental irrigation,” Emadiazar says. “It isn’t necessary to treat it like a potted indoor houseplant that doesn’t receive any outdoor natural rainfall. That’s really the concept behind that.”

You can find Public Works’ weekly watering recommendation on the city’s web site. There, you also can sign up to receive a weekly e-mail containing watering recommendations and other useful information, including how homeowners can set their system to deliver the desired amount. Nearly 1,300 Frisco residents already have taken advantage of the free service.

Some of the new smart controllers available for home use can receive data directly from the weather station. Others that employ soil sensors to measure individual needs can be effective tools as well. The city cross-references its own data with other smart controller data to be sure its findings are within a reasonable margin of error.

If the city’s watering recommendations seem a little light, harken back to the image of your neighbor sending thousands of gallons of water skipping across soaked grass, over pavements, and on down the street.

Dumb? Pretty much. But so is grass. Water too much, and you’ll produce shallow roots. By keeping the water level deeper underground, the roots will have to dig deeper, too, producing richer, healthier grass.

Bottom line: You don’t have to drown your yard to keep it green. It may actually be one of the worst things you can do.

Using the tools and information just an e-mail away, make technology work for you and your landscape. You’ll be doing your bit for a more sustainable Frisco, too.

Weather data displayed. Image: Frisco Public Works