Project Location: Polk County, Iowa
Owner: USACE, Rock Island District
GC: Jensen Construction
Project Revenue: $1,060,393.00
Project Start and End Date: 2015-2016
Summary:
Griffin designed and furnished all equipment for the installation of an eductor dewatering system to facilitate the replacement of the lake’s long-damaged gate system. Griffin installed 14 pairs of eductors up to 100 ft deep and drilled the eductor wells utilizing a floating plant on the outside of the cofferdam. A crane moved the drill rig throughout the site on top of special bracing installed across the top of the cofferdam.
THE CHALLENGE
The Saylorville Lake; Big Creek Diversion Dam controls the outflow of water from Big Creek Lake. The remediation project required construction of a steel cofferdam on the lake side of the dam for the repair and replacement of the existing outlet structure. This repair required an excavation subgrade of 63 ft below the normal pool elevation of the lake.
THE SOLUTION
Griffin installed 28 eductors to a depth of up to 100 ft on the inside of the cofferdam.
THE GRIFFIN DIFFERENCE
Griffin designed and furnished all equipment for the installation of an eductor dewatering system to replace the lake’s long-damaged gate system. Griffin worked with the general contractor to determine an installation method that would work in the challenging over-water conditions.