WASHINGTON CITY — For roughly two years, a segment of Telegraph Road on the hill heading to the Coral Canyon subdivision has been sinking, and no one is exactly sure why.
“A lot of people have the idea that it’s blue clay and it’s heaving — it’s not,” said Mike Shaw, public works director for Washington City. “It’s actually dropping down … over the past couple of years it’s probably dropped 12 inches, maybe more.”
The city has been paving and patching the segment of the road between 1129 East and 1285 East in order to keep it usable and safe until the city is finally able to determine what the cause of the sinking is, Shaw said.
“We really haven’t had a problem with with road until recently,” City Manager Roger Carter said, “so that’s got us concerned.”
The city has recently contracted with the a geotechnical firm to study and monitor the situation on Telegraph Road so the cause can be determined and a solution found.
“A survey’s being done to determine the what is actually happening,” Shaw said. “Right now we’re coming up with trying to get a long term plan and a long term fix.”
Until then, the hill will “just keep slowly moving over time,” Shaw said.
Telegraph Road was originally a state road until it came under Washington City management about 10 to 15 years ago, Carter said, so city officials don’t know if the issue with the sinking may be related to how it was constructed or not.
“We don’t know exactly what the under-lanes of that road could be,” Carter said. “It could be collapsible soils, it could be expansive soils.
The city knows the sinking isn’t being caused by water, Carter said. Springs in the area are not considered a contributing factor, nor are water lines. A water line underneath the road did break recently, but has since been repaired.
“We’re monitoring everything, every possibility, and it’s up to the engineers to tell us what the fix is,” Shaw said.
Until then, the city will continue to do what it can to keep the roadway safe for motorists. Currently road signs warn motorists of an upcoming “bump” where the latest round of repaving has taken place, leaving the spot slightly uneven in parts.
The speed limit has also been lowered from 50 mph to 35 mph.
“We would ask our citizens to be very careful as they go through the area,” Carter said.
Copyright St. George News, SaintGeorgeUtah.com LLC, 2016, all rights reserved.