U.S. Department of Defense
Date of this Version
1999
Abstract
An environmental assessment has been prepared that summarizes the expected effects of the proposed project on the existing environment. This is a project proposed by the Omaha District, Corps of Engineers to halt the erosion occurring along the riverfront at Ponca State Park in Dixon County, Nebraska, and protect the access road to the park's public boat ramp. This project is authorized under the Wild and Scenic Rivers Act amendment of 1978 (Public Law 95-625). The proposed project is located along the right bank of the Missouri River between River Miles (RM) 753.9 and 753.5 at Ponca State Park about 2 miles east of the town of Ponca, Nebraska. The proposed work will involve the construction of a buried revetment 80 feet long, 520 feet of direct bank armoring, and a 91 O-foot long peaked revetment. Notches in the peaked revetment would be 5 feet deep. Two tiebacks would connect the peaked revetment to the shoreline and create fisherman access to the structure. The bank armor and buried revetment would require a combined 1,145 cubic yards of rock, and the peaked revetment would comprise 3,515 cubic yards. The tiebacks would add 410 cubic yards of rock, for a total project of 5,070 cubic yards of rock.
All environmental, social, and economic factors, which are relevant to the proposal, were considered in this assessment. These include, but are not limited to threatened and endangered species, vegetation, wetlands, cultural resources, air quality, water quality, and wildlife. The purpose of the project would be to protect the recreational area on Ponca State Park's floodplain, and to reduce the risk that unchecked erosion caused by the river current and waves could attack the access road to the park's boat ramp. Severe erosion has developed at the site recently after high 1990's flows eroded an island that had been protecting the area from the direct current. Erosion is now threatening the the dirt road to the picnic area, which is now closed to vehicular traffic. If erosion continues unchecked, it could erode into the blacktop access road to the boat ramp.
Adverse effects would include temporary noise, and fugitive dust during construction. There are not expected to be any adverse impacts to threatened and endangered species as a result of the proposed project. Erosion control methods would be utilized during construction. Bank armor above ordinary high water would be covered with topsoil and seeded with native vegetation after construction is complete.
It is my finding, based on the environmental assessment, that the proposed Federal activity will not have any significant adverse impacts on the environment and that the proposed project will not constitute a major Federal action significantly affecting the quality of the human environment. The proposed action has been coordinated with the appropriate resource agencies, and there are no significant unresolved issues. Therefore, an environmental impact statement will not be prepared.
Comments
Published by the U.S. Army Corps of Engineers, Omaha District (1999) 1-39