Saturday’s earthquake moved Jackson’s West Broadway landslide
A 4.8 magnitude earthquake epicentered east of Hoback, Wyoming at around 3 p.m. Saturday also shook the Jackson area.
Town spokesman Carl Pelletier said the West Broadway landslide, which has been creeping towards Broadway at the rate of a quarter of an inch per month, moved about a tenth of an inch following the earthquake. The movement was measured with extensometer monitors located on the surface of the Budge Drive hillside. Deeper instruments, called inclinometers, did not measure a significant increase in movement.
The town of Jackson has both surface and subsurface monitors placed throughout the Budge Drive hillside to indicate any sort of abrupt movement.
The town is taking steps towards mitigating the slide area. Jackson and Teton County residents voted this month to support a 1 percent Specific Purpose Excise Tax (SPET) to pay for stabilization of the town’s portion of the slide area.
The land above the slide was purchased by the Town of Jackson. The house located on the property was demolished to prepare for stabilization work. Prior to that, a temporary drainage system was installed to divert water from the slide area to avoid increased water content and higher risk of slide movement. Budge Drive was also widened to allow construction traffic greater access to the area.
With passage of the SPET, the town of Jackson is moving forward with contractors to establish the stabilization project schedule, cost, and other contract agreements.
A temporary access road will be constructed west of Budge Drive beginning in late September. The road will allow residents of the area to access their homes without using Budge Drive, where construction crews will be active.
Phase two of the project will involve removing weight from the top portion of the slide. At the same time, it will install sheer, key buttresses along either side of Budge Drive. The project will mitigate the town’s right-of-way and protect public infrastructure, including the town’s main water line, a sewage main line, and West Broadway.
The stabilization project will begin in mid-March, 2017 and should be complete by December, 2017.
