Sunday watering ban could save 900 million gallons a summer

By Jackie Valley

Published Thursday, March 17, 2016 | 1:29 p.m.

Updated Thursday, March 17, 2016 | 3:48 p.m.

Lawns in Southern Nevada will have to do without water — unless clouds unleash rain — one day a week during the summer.

The Southern Nevada Water Authority’s board of directors voted today to ban sprinkler use on Sundays from May 1 through Aug. 31. The restriction limits summer landscape watering to six days a week.

The Sunday watering restriction will be voluntary, albeit strongly encouraged, this summer before likely becoming mandatory next year. Individual jurisdictions — Clark County, Las Vegas, Henderson, North Las Vegas and Boulder City — need to adopt the change into their ordinances before it can be enforceable.

The water agency sought the restriction as part of ongoing conservation efforts.

Watering lawns six days a week instead of seven during the hot summer months won’t cause permanent landscape damage or diminish the appearance of lawns, John Entsminger, general manager of the water authority, told the board.

Residents who already skip a watering day tend to do so on Sundays, hence its selection as the summer water-saving day going forward, he said.

“You always want to be letting the community know what’s coming down the pipe while giving them time to adjust,” Entsminger said.

Summer water restrictions already prohibit sprinkler irrigation from 11 a.m. to 7 p.m. to avoid evaporation during the hottest hours of the day. The new restriction stands to save 50 million gallons of water each Sunday and 900 million gallons over the course of the summer, officials said.

Regional water sales are expected to decrease by $1.3 million as a result of the change, water authority spokesman Bronson Mack said.

Board member Bob Coffin expressed concern about how such a ban might affect vegetable and flower gardens that require daily watering.

Entsminger said the Sunday ban addresses “spray irrigation” for turf, meaning hand watering or using a drip-irrigation system for gardens would be acceptable.

The water agency will monitor the change this year and share results with the board next year before it becomes mandatory.

Seasonal watering restrictions aren’t anything new to Southern Nevada. The region has restrictions that limit landscape watering to three assigned days per week during the fall and spring. The restriction is even tighter in the winter, with one assigned day per week for landscape irrigation.

The addition of a summer watering restriction comes at a time when all eyes are on Lake Mead, the region's primary water source. The lake's elevation has been steadily dropping because of the drought and is approaching the level that triggers a water cut.

Lake Mead's current water level is 1,083 feet above sea level, officials said. When the reservoir's elevation falls to 1,075 feet and remains there through Jan. 1, the region's yearly allotment of water from the Colorado River will be cut by roughly 4.3 percent.

Lake Mead's water level could dip below 1,075 feet this summer, but it's expected to increase before the end of the year. Water authorities, however, predict the water level will fall again and remain below that threshold through the end of next year, triggering a water shortage declaration in 2018.