Background/Discussion
The City of Council Bluffs owns or sponsors multiple levee segments which encompass the City Federal Levee System, providing flood protection from the Missouri River, Mosquito Creek, and Indian Creek. These levee systems are currently shown on FEMA floodplain maps as being accredited and are identified as providing protection from the 100-year flood or 1% annual chance flood event.
In order to maintain the level of protection identified on the FEMA Flood Insurance Rate Map, it is necessary to provide documentation to FEMA that complies with the requirements of 44 CFR 65.10. If the levees are not certified, they will be de-accredited and FEMA will begin the process of updating maps. Areas previously protected by the levees will be identified as flood-prone. In order to meet the criteria for levee certification, improvements to each of the levee systems will be necessary. The purpose of the Drainage MR_2 project is to replace deteriorated drainage structure pipes, rehabilitate the associated gate well structures, and remove unacceptable tree, utility and fence encroachments.
During execution of the project, additional items of work have been identified that were not included in the bid. Additional flowable fill is required due to the added length of pipe replaced with C.O. #1. Certain parts required for the gate repairs are unavailable and a more extensive replacement is necessary. A ring levee was required to be constructed by the USACE because of the high river conditions during the spring. The changes in work and large lead time for parts also requires a time extension. Without these modifications to the project, the work cannot be completed and the requirements for certification will not be satisfied.
Change Order #1 which added $55,747.62 for the replacement of additional pipe was previously approved by Resolution No. 18-69.
Change Order #2 will add $29,317.89 to the total project cost. This amount exceeds the threshold for change order approval by the Director and Mayor and requires City Council approval.
The revised total for the project will be $970,421.33, including C.O. #1 and #2.
The FY17 CIP included $2,278,000 funded by the Iowa Flood Mitigation Program and $2,722,000 in Sales Tax Funds programmed for levee improvements. The total budget for this project was $1,100,000.