As the result of an ordinance adopted Thursday, irrigation on new residential development in Sun Valley will be limited to half the lot or half an acre, whichever is less.
The City Council—voting unanimously—has expressed approval of the ordinance since it was first presented in early November, but had to go through the required process of three public readings.
Sun Valley Water and Sewer District Manager Pat McMahon said the district isn't constantly running near maximum capacity, but summertime peaks bring it close—not out of necessity but because of grass watering.
The water system consists of 11 wells and 10 reservoirs with a maximum capacity of a little more than 11 million gallons per day. McMahon said winter use ranges from 1.5 million to 2 million gallons per day. That quadruples to an average of 8 million gallons per day in the summer.
Councilman Nils Ribi said he knows the situation, sometimes seeing "bubbles" coming out of the faucet in the summer.
"It's inevitable that this has to be done," he said.
Councilwoman Joan Lamb said it would be "irresponsible" to ignore recent summertime peaks that have come close to exhausting the water system's capabilities. Plus, she said, the ordinance will immediately "educate" people moving to the area that the water supply isn't infinite and restrictions exist.
The ordinance provides a couple of exceptions allowing for more irrigation than stipulated. One example is "temporary irrigation for revegetation of areas that were disturbed during construction." That exception is allowed for up to two growing seasons after landscape completion.
The exception for permanent irrigation applies to drip systems installed solely to water trees in "natural grass areas" where there is little to no irrigation. The drip system won't be counted in the ordinance's limitations as long as it does not irrigate beyond the 'drip line' of the trees to surrounding vegetation.
McMahon said the district is planning a future change that would drastically reduce consumption by relying on reused water for golf course irrigation and snowmaking for the River Run part of Bald Mountain.
Besides serving River Run, the district also serves St. Luke's Wood River Medical Center and McHanville outside of the city limits.
Trevon Milliard: tmilliard@mtexpress.com
