RAIN SATURATES HILLSIDE SLOPES; GRAVITY SENDS MUD, ROCKS SAILING
ksl.com
The recent rains have caused more than a fear of flooding, as canyon hillsides are threatening to collapse and roads are being covered with mud.
“We’ve had this continuous rainfall that really started back in October,” said Jeff Niermeyer, Salt Lake City Public Utilities director. “It has just rained and rained and there’s no place for the water to go.”
The hillside at the mouth of City Creek Canyon, he said, has been sliding under increased water pressure since 1937, but has already moved 8 feet this spring with all the recent moisture.
“It starts to saturate the upper surface of the groundwater and what that does is basically relieve the inner pressure between the soil particles and creates the potential for landslides,” Niermeyer said.
Excess water sent an estimated 200,000 tons of rocks and mud onto state Route 39 Thursday evening, damaging at least two cars and closing the road on the southern shores of Pineview Reservoir for most of the day. Utah Department of Transportation engineer Brent DeYoung said the hillside had been stabilized, but more rain could change that.