Status: In Progress
The preliminary engineering design has been completed and the project components have been identified for managing sand and sediment accumulations within Zink Lake. The required local, state and federal permits and clearances are in progress. The Environmental Assessment has been completed, and the U.S. Army Corps of Engineers, who has regulatory jurisdiction and permitting authority over this project, issued the 404 permit in January of 2014. Since then the USACE has requested additional information, and the draft revised 404 permit is being prepared. Additional mitigation implementation was also requested by the USACE which will require additional engineering design for final revision. Vision 2025 dedicated $2.1 million to this project. A portion of this funding has been used for the environmental studies and engineering design of the proposed project. Matching grant funds from the U.S. Geological Survey, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers have been utilized in this project.
With the introduction of the Gathering Place on the east bank of the river, updates to the preliminary design report and cost estimates are necessary to become consistent with the Gathering Place design. Coordination with the design team is helping develop a scope of work that will address the USACE requests and yield a revised 404 permit for Zink Dam improvements.
The originally proposed method of managing the sand and sediment accumulations within Zink Lake was to excavate a hole in the riverbed and dredge its sand accumulations. Much of the area proposed for the excavated hole is already scoured to bedrock and does not have the sand depth suitable for this method. The Arkansas River was once a sand-dominated prairie river, but that has changed with the completion of Keystone Dam. Since the construction of Keystone Dam and formation of Keystone Lake, natural sand and sediment loadings from upstream sources have been diminishing. This trend is expected to continue as long as Keystone Dam remains in place. Studies have recommended a more sustainable alternative. Adding more full-height gates to the mid-section of Zink Dam will increase capability to scour sand from Zink Lake during high-flow conditions. The existing Zink Dam has only 150 feet of gate opening along the 1400-foot length. The proposed plan would replace the existing gates and add gates to the midsection of the dam. Sand would then flow downstream during high-flow conditions, rather than being trapped by the solid dam.