August 5, 2014 around 6:00 a.m., after a few days of heavy rains, the slope above Parkway drive in North Salt Lake City Utah, gave way creating a landslide that pushed one house off of its foundation and took over part of a tennis court. Residents had reported, for many months leading up to the slide, the earth was starting to move and creating cracks. The slide created a 60-foot-high main scarp above the landslide mass. The landslide was about 500 feet wide and 500 feet long.
This slope was destined to fail from the beginning. In the 1990's this was the site of gavel quarry and when the property was excavated for development the slope was steepened. After the slide, geologists determined that the site has volcanic deposits that turn to clay when repeatedly exposed to water. They also noticed fine-grain sediments from just below the shoreline of the prehistoric Lake Bonneville. This combination is a recipe for a disaster.
The remediation included regrading much of the slope to lower its overall steepness, and installation of a drainage system to collect water from the slope and transport it off the landslide to the local storm drain system.
Below is a link to live coverage of the slide captured by a local television station.
Live coverage of slide
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