|Description of Project
The Smithsonian Intuition, with NCPC as lead federal agency and the National Park Service as a cooperation agency, has prepared an Environmental Assessment (EA) to examine the environmental impacts of the construction of a retaining wall between the General Services Building and North Road on the National Zoological Park. The purpose of the project is to structurally stabilize the General Services Building and remove existing hillside loads from the building.
The EA includes four alternatives, one no action alternative and three action alternatives. Action A, the no action alternative, analyzes the continued current management operations and conditions. Alternative B, the straight wall design, analyzes a straight retaining wall, approximately 945 feet in length that varies in height from approximately 40 feet tall on the west to an at grade tie-in on the east end. Alternative C, the soil berm design, includes the construction of a straight retaining wall, similar to Alternative B; however, Alternative C includes soil berms in order to minimize the visible height and length of the proposed wall. Alternative D, the terraces design, would include the construction of a straight retaining wall as well as multiple terraces to break-up the visual mass of a single retaining wall.
The EA also evaluates two alternatives to the conditions of North Road, a road on the Zoo property. Option 1 would provide approximately 3.5 feet of planning between a proposed retaining wall and the future expansion North Road. Option 2 would provide up to 13 feet of planning area between the future roadway expansion and a retaining wall.