ITEM TITLE:
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Approval of Change Order #2 with Harris Sand and Gravel for the 10 Mile Dike Maintenance Project in the Amount of $472,136.00
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SUBMITTED BY: Nathan Duval, Capital Facilities Director
FISCAL NOTES:
Expenditure Required: $472,136.00
Unencumbered Balance: $1,223,946.63 ($798,946.63 if CO#1 Approved)
Funding Source: 350-0750-55000.409
RECOMMENDATION:
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Approve Change Order #2 with Harris Sand and Gravel for the 10 Mile Dike Maintenance Project in the Amount of $472,136.00
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SUMMARY STATEMENT:
Background: The project currently underway on the Lowe River is designed to first be a maintenance project repairing the dikes and adding rip rap for a toe and armoring the existing banks and secondly establish a base for a future dike raise. The design is phased so that a future dike raise can be accomplished on top of the newly renovated dike system without redoing current work. The maintenance is currently underway on groins 1, 2, and 4. Groin 3 does not currently see significant flow from the Lowe River directly contacting its bank; it is protected by yet to erode land in front of the dike.
The proposed change order is the result of additional aggradation at the toe of groins 1,2,&4 resulting in excess gravel needing to be removed for the placement of the new toe. The excess gravel is currently temporarily staged in front of the dikes on the river side.
The approved drawings allow for the excess fill material to be used on top of the dikes; otherwise it will need to be leveled out in the riverbed. Significant concerns exist with the natural rise in the river bed elevation. Leaving excess material in the river only accelerates those concerns.
Working with the Engineers, DOWL, and the contractor we have calculated that we can use the excess material to raise the dikes an average of 3 feet. The dikes would be armored in accordance with the current and future plans and specifications with a 3:1 slope, class 1 filter rock layer, and a class...
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