October 28, 1997
Brigadier General Francis Laden
Nebraska Army National Guard
Acting Assistant Director, Nebraska Emergency Management Agency
1300 Military Road
Lincoln, Nebraska 68508
Subject: Hazard Mitigation Grant Program Project: Western Sarpy Levee, Sarpy County, Nebraska
Dear Brigadier General Laden:
I am writing to you with regard to the appeal submitted by your office for the proposed Hazard Mitigation Grant Program project for the Western Sarpy levee in Sarpy County, Nebraska. We have performed a detailed engineering, economic, and program eligibility review based on your appeal. We appreciate the cooperation from your staff, the Nebraska Natural Resources Commission, and the Papio-Missouri River Natural Resources District. This cooperation has greatly aided FEMA in making a thorough evaluation of this project In our review process, we uncovered information which was not available to our regional office at the time of their review.
Based on review and engineering analysis, FEMA will approve the proposed mitigation project based on the applicant's original proposed total construction cost of$2,314,242 (the 75% Federal Share would be $1,735,682). The approval is based on the following provisions:
1. The levee will be constructed to the 50-year flood elevation, (excluding the effects of ice jams, see #2 below), determined in the hydraulic analyses prepared by our contractor, Woodward-Clyde Federal Services. FEMA has determined that constructing the levee to this height will not result in a floodway violation under the National Flood Insurance Program. It should be noted that any increase in levee height above this 50-year level would result in a flood way violation.
2. Final design plans based on the above mentioned levee height, along with supporting engineering design information (e.g., geotechnical data, levee cross-sections, etc.) should be submitted to FEMA for approval. Additionally, an Operation and Maintenance (O&M) plan for the levee should also be submitted. It is especially important that the O&M plan address access and maintenance of the 200-foot corridor along the levee and provisions to be implemented for combating the impacts of ice jams along the Platte River. The benefit/cost analysis for this project was based on non-ice jam conditions. Historically, ice jams have been significant factors in flood events along this reach of the Platte River. Balancing the competing interests of ice jam induced flooding and floodway rise, compliance with Executive Order 11988, and maintaining strict floodplain management behind the levee will be difficult. Consequently, the applicant should have prescribed actions that will be implemented to minimize these impacts and maintain the integrity and performance of the proposed levee. It is our expectation that the applicant, the Papio-Missouri River Natural Resources District, will successfully navigate these interests and satisfy all interested parties before construction begins.
3. The proposed levee does cause induced flood hazards for property on the riverward side of the levee in Sarpy County and for property on the Saunders County side of the Platte River. These induced flood hazards were quantified in the hydraulic analyses performed by our contractor. The applicant should notify impacted property owners and stakeholders (e.g., Camp Ashland, Saunders County, Thomas Lakes, and Beacon View) to inform them of the induced hazards and to address any concerns that they have based on the proposed project. It is imperative that this local flood plain management coordination be accomplished prior to construction of the project. FEMA will be happy to provide the applicant with information about the induced damages.
4. Any requests for additional funds above the originally estimated construction cost of $2,314,242 (75% Federal Share $1,735,682) must be submitted to FEMA and the State of Nebraska with justification. Any additional funds would require separate review and approval from FEMA.
5. An Environmental Assessment (EA) must be prepared for this project by FEMA to meet the requirements of the National Environmental Policy Act (NEPA). The EA must result in a Finding of No Significant Impact (FONSI) prior to FEMA's release of funding for this project. I do not envision this to be a problem and I assure you that FEMA will complete this environmental evaluation in a timely manner to ensure that the construction of the project is not unnecessarily delayed.
Again, I wish to express my appreciation for your cooperation and patience in evaluating this project. If you have any questions or concerns with this determination, please contact either me at (202) 646-3672, or Mr. Craig Wingo, Deputy Associate Director for Mitigation, at (202) 646-3026.
Michael J. Armstrong
Associate Director for Mitigation