ST. GEORGE — While area residents have been urged to restrict their outdoor water use during the day, sprinklers can still be seen watering cemeteries, golf courses, school grounds and other large properties in the middle of a severe drought.
Is this because the county and its municipalities are callously wasting water for the sake of green grass while encouraging residents to let their own lawns turn yellow?
That’s not the case at all, say county and municipal water managers.
There’s actually a difference between the quality of water people use to water their lawns and gardens versus the water the county and cities use to water their parks, cemeteries and golf courses.
Drinking-grade water versus irrigation-grade watering
Drinking-grade water, also commonly referred to as culinary water or potable water, is water that has been treated to the point it is safe to drink. For residents, it’s the water that comes out of their faucets, shower heads and sprinkler systems.
Irrigation-grade water, also called secondary water, isn’t up to drinking standards and also may not be feasible to treat for drinking use for various reasons. This can include water taken directly from wells and streams and treated sewer water and reuse water. This water is used for agriculture watering, and is also applied to a city’s parks, sports fields, golf courses and cemeteries. School grounds also use this water source.
Issues of storage
Culinary and secondary water also have their own delivery systems. Culinary water systems tend to be very robust and sport a sizable storage capacity that can come in the form of water storage tanks and reservoirs. For example, St. George sports an estimated culinary water storage capacity of 59 million gallons.
This system allows water to be held during the day until it can be used by residents for outdoor watering. Conversely, the area’s secondary water systems are not as robust in delivery or storage capacity.
“It all goes back to storage capacity of the irrigation system,” Scott Taylor, St. George’s water service director, told St. George News.
While St. George’s secondary water system has some storage in the forms of the fishing ponds found on Red Hills Parkway and Snow Canyon Parkway, it has nowhere near the storage capacity of the culinary system. Because of this, the water needs to be allowed to flow through and be used as it is available – this is a reason why people can see parks and golf courses being watered during the day.
Staggering the use of the water throughout the day also helps to keep the system itself from running dry, as waiting to use the water all at once could pose a problem, Taylor said.
“The system would run dry,” he said. “There’s not enough storage capacity, there not enough pipeline capacity. That’s the reality of it. We just don’t have the capacity and the storage or distribution system in order to water like we’d like to.”
In Washington City, Public Works Director Mike Shaw said the city observes the watering restrictions recommended by the state and water district where possible. Unfortunately, large outdoor facilities like cemeteries and sports fields cover such a wide area, parts of them have to be watered on a rotating basis though the day, which doesn’t mesh well with current day-time watering restrictions.
“The piping system can’t water everything at the same time,” Shaw said.
The Washington County Water Conservancy District also deals with this issue, said Zach Renstrom, the water district’s general manager.
When asked if upgrading the secondary water system of the county and the cities was a possibility, Renstrom said the costs would be “astronomical.” It would also bleed down to the end users, which would include the remaining farmers in the county.
“Most of our secondary water feeds agriculture use, and farmers already operate on thin margins,” Renstrom said. “An increase in that water could put them out of business.”
Despite current issues surrounding the secondary water system in St. George, Taylor said he believes the system will become more manageable in the future as the city continues to grow. New developments are required to build more adequate secondary water systems, which will help the city in the long run, he said.
Where “feasible and economical,” Renstrom said the water district is continually working on making its secondary water system as effective and efficient as possible. Part of this includes metering the system.
Benefit of the secondary water system
Using the secondary water system allows the county and its municipalities to save on culinary water use, as that water isn’t being applied to the parks, golf courses and so on. It also helps keep the overall costs of water down, Renstrom said.
“To treat water is quite expensive and it consumes a lot of electricity to get water to a culinary level of treatment,” he said.
As attempts to treat some sources of secondary water can prove too impractical and expensive, Shaw added that using that water in place of culinary water for outdoor facilities was “just a wise use of resources.”
Still, with the continuing state of the drought and over 50% of the counties culinary water going to outdoor use, Renstrom, Shaw and Taylor each encourage residents to practice water conservation.
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