Roseville takes emergency action on Fiddyment sinkhole

Roseville officials plan to take emergency action this week to fix a dangerous sinkhole at the Old Fiddyment Road trail bridge, authorities said. Roseville Public Works staff last December were informed of a sinkhole next to the bike path across Pleasant Grove Creek north of Orchard View Road in west Roseville. The hole is adjacent to two old culverts with corrugated metal panels, staff said. The total creek crossing is about 70 feet. By reviewing record drawings, Roseville staff found the culverts were originally built in then-unincorporated Placer County in 1976 as the creek crossing of original Fiddyment Road. Fiddyment Road has since been rerouted as part of the West Roseville Specific Plan, and the original crossing was converted to a bike trail crossing of the creek. The sinkhole was apparently caused by a hole in a section of deteriorated metal culvert, which pulled soil into the creek during high runoff. Roseville staff began planning for a rehab project for the summer once the wet season ends. Staff made a temporary repair and brought in a structural engineer to help identify future repairs. City workers also continued to monitor the area if more immediate action was needed. During a post-storm inspection Feb. 5, a new sinkhole was found, and signs of structure failure were evident. Due to the magnitude of damage, staff closed the creek trail crossing to the public and determined an emergency repair was necessary before the next rain forecast to prevent "complete failure." "Failure of the culvert could result in its collapse, which would partially block the creek and could result in upstream flooding," Senior Engineer Jesse KhatKar said in the council report this week. "This could have put homes and properties at risk." Taking emergency action yields better odds to be salvaged and repaired rather than replaced. "An initial estimate of full replacement costs could reach $2 million," staff said. Since the Feb. 5 closure, staff continued to consult with a structural engineer and formed an emergency construction contract with DeSilva Gates. The contractor dug out soil from above and adjacent to the area and placed erosion controls, staff said. To date, about $100,000 has been spent on the repair effort. If the repair is successful, staff anticipates the repair will cost $250,000, said Public Works Director Jason Shykowski. If a repair is unsuccessful, staff may need to remove the structure and plan for a future replacement. The current contract of $600,000 will allow staff to address the repair without another council approval, officials said. Half of the amount will come from city contingency funds and half transportation funds. The Roseville City Council was scheduled to take action on the matter at the regular bi-monthly meeting Wednesday evening.