- Data collection and analyses
- Levee inspection
- Slope stability analyses
- Hydrologic and hydraulic modeling
- Levee repair
- Construction documents
- Bidding assistance
- Construction administration
The Pender-Logan Creek Levee is part of a levee system located along a tributary to the Missouri River. The levee system is comprised of an earth levee segment and concrete floodwall along the right bank of Logan Creek. Specific features of the levee system include drainage structures, two closure structures, and riprap protection. The total length of the levee segment is 2.44 miles and the total length of the floodwall is approximately 2,330 feet. A flood event overtopped portions of the levee and resulted in numerous slope failures, bank caving, and damage to four interior drainage structures, including one structure that completely failed.
The project required developing full repair design documents within an expedited four-month period so that the repairs could be constructed prior to the spring runoff season.
RJH was retained by the U.S. Army Corps of Engineers – Omaha District (USACE-NWO) to provide design and construction engineering services. The selected design option involved installing a sheet pile wall near the toe of the right channel bank, placing fill to restore the channel bank, placing riprap over the fill for erosion protection, and replacing the damaged interior drainage structures. RJH used data from previous subsurface investigations by the USACE-NWO to establish material properties and perform slope stability evaluations. Hydrologic and hydraulic modeling was performed both with and without repairs to confirm that the repairs would not substantially change flow regimes in the channel.
RJH coordinated with USACE-NWO and other stakeholders to fully understand design preferences. Additional responsibilities included developing limits of permanent and temporary easements required for construction, and identifying solutions for construction challenges including construction access and haul routes, staging and stockpiling areas, etc. RJH supported USACE-NWO during construction by performing periodic site visits to observe construction, reviewing submittals and other key construction documentation, and developing record drawings.