Emmett Sanders Lock and Dam is located at navigation mile 66 on the Arkansas River within the Lower Arkansas River Watershed and is a part of the McClellan-Kerr Arkansas River Navigation System. It is located within Jefferson County, Arkansas, east of Pine Bluff and west of Altheimer. The ESLD is the 4th L&D of the 18 lock and dams along the MKARNS, with U.S Route 79 running directly over it.
The MKARNS is 445 miles long and stretches from the Port of Catoosa near Tulsa, Oklahoma, downstream to the confluence of the Mississippi River in southeast Arkansas. The project area resides completely within USACE federal property and will not involve in any part of the Arkansas River. However, it will use a part of the Sheppard Island Public Use Area as a temporary lay down area for repair and construction equipment and for place of where the mitigation would occur.
The area of water that ESLD controls and maintains begins at ESLD and proceeds upstream to Maynard L&D at nautical mile 86. The authorized purpose of the ESLD is to provide for navigation with the larger MKARNS having to support for recreation, fish and wildlife, water supply, and irrigation.
The purpose is to increase protection and resilience of the left embankment from erosion and scouring during future flood events.
The need for the Proposed Action arises from the 2019 flood event, after which temporary measures were put in place, however, a more permanent solution is needed as the current solution does not adequately protect against larger flood events. Without increased protection, the embankment that ties in the lock, dam and road are at a higher risk of substantial damage during future flood events.
1.1. Scope of the Action
The project’s scope is to implement permanent repairs to the left embankment at ESLD. The project is a follow up effort resulting from unfiltered seepage through the embankment found on the downstream face of the left embankment. The work would consist of removal and replacement and or installation of impermeable materials, random fill, scour protection, and pavement materials to restore the left embankment to original design intent based on the dimensions, plans, and specifications. The design intent is to provide an embankment to design grade resilient against internal erosion failure modes such as backwards erosion piping (BEP) armored sufficiently to protect against external erosion (overtopping, scour, wave- action.) Additionally, 1.6 acres of bottomland hardwood forest (BHF) would need to be cleared to prevent future void formation in the embankment materials and to allow for the safe passage of emergency vessels. Work may require excavation, grading specified soil and rock, meeting specified compaction of soil and rock, placement of geosynthetics, and cutting, clearing, and grubbing trees, shrubs, and other tall vegetation.
Mitigation for the loss of 1.6 acres of BHF would occur via planting and maintaining 1.75 acres of fallow field to BHF within the Sheppard Island Public Use Area.