Hillside drops as work on sinking Telegraph Street begins

WASHINGTON CITY – Work began Tuesday on creating an earthen buttress meant to counteract a gradual slide that has been plaguing a section of Telegraph Street east of Washington Parkway since December.

Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, nessitating a closure of a section of Telegraph Street until the hill is considered stabelized by city officials, Washignton City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News
Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machinery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, necessitating a closure of a section of Telegraph Street until the hill is considered stabilized by city officials, Washington City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News

However, as work commenced, the hillside moved more in one day than it had in the last nine months. This has prompted the city to close access to Telegraph Street between Washington and Highland parkways temporarily and bumped the contractor involved in the project up to a round-the-clock schedule.

JP Excavation, a local contractor who won an expedited bid for the project, began work Tuesday morning. Before they could begin to move the earth that would be used to create a buttress to shore up the hillside, they began to remove vegetation, boulders and other debris from the toe of the hill.

It is believed clearing the toe of the hillside in preparation for the earthwork triggered a slide that dropped the roadside above by approximately 6 inches. Previously small cracks in the middle of the road were turned into miniature canyons as the drop became much more pronounced.

Mike Shaw, Washington City’s public works director, addressed the issue at the Washington City Council work meeting Tuesday night.

“About 3:30 I got the call that the hill had moved a lot more today than it has in previous days,” Shaw said.

Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, nessitating a closure of a section of Telegraph Street until the hill is considered stabelized by city officials, Washignton City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News
Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machinery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, necessitating a closure of a section of Telegraph Street until the hill is considered stabilized by city officials, Washington City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News

By 4:30 p.m., that segment of Telegraph Street was closed. This has locked off access between Washington City’s downtown and the Coral Canyon development. The only way to access that part of Washington City now is via Interstate 15 at Exit 16 onto state Route 9.

“We’re trying to err on the side of safety,” Shaw said of the road closure, adding that he hopes to reopen the road in a day or two. This is contingent on the satisfaction of Shaw and a geotechnical engineer that the hillside is stable enough for traffic again.

Prior to the closure, the five-lane roadway was reduced to two-lanes with a speed limit of 20-25 mph. Should all go as hoped, that arrangement will return in a couple of days.

In order to help speed up the process, JP Excavation crews have been put on a 24/7 schedule, Shaw said. They originally had 14 days to build up the earthen buttress to help stop the slow-moving slide, but now it is likely they will be done a little bit faster.

“Things are going very, very quickly,” Shaw said.

Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, nessitating a closure of a section of Telegraph Street until the hill is considered stabelized by city officials, Washignton City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News
Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machinery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, necessitating a closure of a section of Telegraph Street until the hill is considered stabilized by city officials, Washington City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News

Other than the extended schedule, Shaw said Tuesday’s incident doesn’t change the city’s plans. They believe the construction of the buttress from the bottom of the hillside upward will help act as a counterweight of sorts and hopefully cancel out the slide.

From there, the city will wait for the slide to settle out and then begin repairs on Telegraph Street. This will involve relaying various pipelines under the road and the reconstruction of the roadway itself.

Infrastructure beneath the roadway that will have to be relaid or possibly replaced may include fiber optic lines, a sewer line and water line.

Both a water and natural gas line running through the slide zone have since been capped and rerouted through other lines, Shaw said. Aside from a sewer line that sometimes slips out of a socket and needs to be reattached occasionally, there are no major leaks from the lines occurring in the slide zone.

While a crew running heavy equipment moved an estimated 3,000 yards of earth an hour, utility works started to reroute power line through new two poles. Two of the preexisting poles – one in particular – are in the slide zone and have begun to lean.

While the issue of the sinking road really didn’t start picking up speed until December 2015, Shaw previously stated there had been a gradual drop in the roadway over the prior two years.

Since the sinking began to speed up, the city has monitored the issue. This has taken the form of marking 30 survey points on the hillside for measurements, as well as the installation of inclinometers in the hillside to help determine the size and speed of the slide.

Washington City residents have asked city officials why they hadn’t addressed the issue sooner.

“’Why haven’t you done something?’” Shaw said, echoing residents’ questions about the hill. “Well, we’ve got to know what to fix before we try to fix it.”

Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, nessitating a closure of a section of Telegraph Street until the hill is considered stabelized by city officials, Washignton City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News
Work on creating an earthen buttress designed to counteract a slow-moving slide on hillside between Washington and Highland parkways in Washington City began Tuesday. However, as heavy machinery began to clear the ground at the foot of the hillside, the slide dropped 6 inches, necessitating a closure of a section of Telegraph Street until the hill is considered stabilized by city officials, Washington City, Utah, Sept. 27, 2016 | Photo by Mori Kessler, St. George News

Originally it was thought that the sinking hillside was caused by a settlement issue. However, after additional studies conducted by three different geotechnical engineers, the problem was determined to be a slow-moving slide.

After the cause was identified, a solution was proposed and adopted soon after. The overall estimated cost of the Telegraph Street reconstruction project is $1.5 million, Shaw said.

Two agencies the city has worked with to address the slide issue are the Army Corps of Engineers and the School and Institutional Trust Lands Administration, also known as SITLA.

Both agencies have been great to work with, Shaw said, and have allowed the city the necessary permits and means to move forward on the project.

The city was able to secure an emergency permit from the Army Corps of Engineers in order to work on the base of the hillside due the presence of a wash there. Part of the permit involves restoring the effected part of the wash once the buttress is completed.

Overall work on the Telegraph Street project is estimated to be completed sometime in January 2017. If all goes well and the road reopens, Shaw said he hopes to keep the road open during repair work.

Click on photo to enlarge it, then use your left-right arrow keys to cycle through the gallery.

Email: mkessler@stgnews.com

Twitter: @MoriKessler

Copyright St. George News, SaintGeorgeUtah.com LLC, 2016, all rights reserved.

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1 Comment

  • digger September 28, 2016 at 3:58 pm

    I suggested You let It slide, someone is gonna get Buried!!
    You cant Stop Mother nature!
    Refer To My post On previous Clip!

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