Wednesday, November 16, 2016

Trees, grass, drought and the future

Can lush lawns be sustained with future droughts and water supply issues looming? Photo: Mary Newsom
Water and our supply of it is on my mind this week, as a smoky haze drifts around Charlotte, reminding us of the wildfires in the tinder-dry N.C. foothills and mountains west of the city. It’s been abnormally hot and dry  for months in the Appalachians and the Southeastern U.S. Two Western North Carolina counties are now in exceptional drought and seven others in "extreme drought." 

In the Charlotte region we’re currently in Drought Stage 1 (moderate drought, voluntary watering restrictions). Boat ramps at lakes Norman and Wylie just outside the city have been closed. Some of our shrubs are succumbing. And my guess is we’ll move into Stage 2 (severe drought) shortly after the start of December.

The city's water-sewer utility, Charlotte Water, has a keen interest in encouraging people to conserve water, and not just in a drought, although they tend to concentrate the mind, so to speak.

Taking the long view, Charlotte Water officials see that relentlessly sucking more water from the local reservoirs – Mountain Island Lake and Lake Norman – is not a strategy that can sustain the area's growing millions of residents in future decades. Further, towns and cities downstream of Charlotte use the same river (dammed decades ago into a series of lakes by what's now Duke Energy ) for their water supplies, so draining it is not an acceptable option.

So Charlotte Water officials are eyeing the area’s beloved lawns as a way to reduce water use. On an average day, the utility pumps 100 million gallons of treated water each day, says Jennifer Frost, public affairs manager at Charlotte Water. But during the summer that’s been from 130 to 135 million gallons a day – due to people irrigating lawns. “I think we hit 143 one day in August,” she said recently.

But Frost notes that suggesting people reduce the size of their lawns in favor of more drought-tolerant plantings hasn’t, in the past, been a winning message. So she hopes the utility can, instead, join with local efforts to encourage more tree planting and better care for existing trees.
“Inherent to growing a canopy is that reduction in turf grass,” Frost says. And, she says, “We will not get to the next level of water conservation without reducing the level of irrigation that we use.”

For the record, here are the requested water restrictions for Charlotte, for now:
  • Irrigate only on Tuesdays and Saturdays between 6 p.m. and 8 a.m.
  • Limit landscape watering to 1 inch of water per week, including rain.
  • Conserve water indoors and outdoors.
  • Refrain from outdoor water use during the day (6 a.m. to 6 p.m.) to reduce evaporation losses.
  • Don't fill swimming pools, and top off full pools only on Thursdays and Sundays, 6 p.m. to 6 a.m.
  • Turn off water fountains and other decorative water features.
  • Use commercial car washes that recycle water, not your home hose.