DEPARTMENT: Transportation & Capital Improvements
DEPARTMENT HEAD: Mike Frisbie, P.E.
COUNCIL DISTRICTS IMPACTED: Council District 6
SUBJECT:
Twin Falls Cliff-Bank Stabilization Project
SUMMARY:
An Ordinance for the Twin Falls Cliff-Bank Stabilization Project, a Storm Water Regional Facilities Fund Project, located in Council District 6, authorizing a construction design-build contract to Hayward Baker, Inc.-Craig Olden Division, in an amount not to exceed $719,300.00.
BACKGROUND INFORMATION:
Project Background
Through the annual budget process, $2,900,000.00 from the Storm Water Regional Facilities Fund was authorized for the Twin Falls Cliff-Bank Stabilization Project. Of the total amount, $709,300.00 will be used for construction and $370,000.00 for engineering, design, environmental, and project management. The balance of the Project funds approved may be used for real estate or else returned to the Storm Water Regional Facilities Fund.
Over the years Leon Creek has eroded a 750-foot section of the southern creek bank, resulting in the creation of a 20-30 ft high cliff, potentially impacting the private properties along the 7300 Block of Twin Falls located in the Twin Creek Subdivision in Council District 6. In June 2014, a Preliminary Engineering Report (PER), performed by LNV, concluded that the creek wall will continue to erode towards the private properties and recommended a retaining wall system be installed. In February 2015, during the detailed design of the retaining wall by Maestas & Associates, the City was notified by the consultant that the current safety factor of the existing wall, although considered stable, was below the minimum standards and therefore recommended the City to take more immediate actions.
The Twin Falls Cliff - Bank Stabilization Project will mechanically armor a 30 foot vertical cliff by installing a Soil Nail Retention System. Soil nailing is an earth retention technique which...
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