Council Bluffs levee project receives helpful funding

The city of Council Bluffs and JEO have reason to celebrate! Together, they worked hard to receive $57,000,000 in financial assistance from the Iowa Flood Mitigation Program for the city’s flood mitigation project.

cb leveeNews of this funding assistance is both exciting and crucial to this $114-million project, which involves numerous improvements to an aging levee and drainage channel system. Without funding from the Iowa Flood Mitigation Program, the city of Council Bluffs would have had to divert funds from other planned capital improvements and possibly delay implementation of portions of the project. Additionally, the lack of financial assistance would have resulted in flood risk for the community and forced the city to incur a significant amount of municipal debt.

about the system-01The Council Bluffs levee system, which protects the city from major flooding, was constructed in sections from 1946 to 1954. Approximately 28.5 miles in length and running along the Missouri River and two tributaries, Indian Creek and Mosquito Creek, the levee system provides direct flood risk reduction to approximately 64 percent of the incorporated limits of the city.

Since its construction, the levee system has provided flood protection from a number of significant flood events, most recently in 2011 when Missouri River water levels exceeded the 1% annual exceedance probability (100-year) flood elevation for approximately 90 days. Though the levees did not fail during the 2011 flood, the design safety factors were lower than required levels. The city received $20.4 million in federal emergency assistance for flood fighting efforts and to rehabilitate damaged areas of the levee system after floodwaters receded.

During its ongoing flood hazard remapping process in 2011, the Federal Emergency Management Agency (FEMA) asked the city of Council Bluffs to certify the levee system meets current criteria, including the ability to protect against the 1% annual exceedance probability flood. To assist in this process, the city partnered with JEO. Through a detailed evaluation and feasibility study of the existing levee system, JEO identified deficiencies at various locations.

Severe economic consequences would occur if the levee system is unable to meet FEMA’s levee accreditation standards. Levee de-accreditation would prompt FEMA to revise the city’s flood insurance rate maps (FIRMs), thereby reclassifying 9,830 residential structures and 943 non-residential structures as being within a special flood hazard area. Additionally, revised FIRMs would (1) require flood insurance for residents and businesses with federally-backed mortgages, (2) significantly increase flood insurance rates for residents and businesses in the area, and (3) lead to building restrictions according to the floodplain management standards, such as elevation requirements for new construction and re-development. These new costs and development restrictions would have significant effects on economic development within the city.

Needing to bring the levee system up to current design and accreditation standards, JEO outlined 22 unique improvements. These improvements will increase the redundancy, resiliency, and robustness of the levee system, and reduce the city’s flood risk. Scheduled over the 10 years, the improvements are phased according to a variety of factors, including priority, scope, and cost.

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By | 2017-06-08T14:32:37+00:00 August 6th, 2014|Engineering, News, Project|0 Comments