CFA 18/FEB/10-2

Owner
National Park Service
Property
Lincoln Memorial Reflecting Pool and Grounds, West Potomac Park
Description
Rehabilitation of pool, landscape improvements for Elm Walks, and installation of security barriers for east plaza of the Memorial
Review Type
Revised concept
Previous Review

Letter

Dear Ms. O'Dell:

In its meeting of 18 February, the Commission of Fine Arts reviewed the revised concept submission for perimeter security, accessible circulation, and landscape improvements east of the Lincoln Memorial including rehabilitation of the Reflecting Pool. The Commission commended the design team for its thorough response in presenting design development alternatives and approved the concept with the following recommendations.

For the treatment of the plaza east of the Memorial Circle and the associated perimeter security elements and access walkways, the Commission members approved the preferred configuration as having the least visual impact on the Lincoln Memorial. For the plaza pavement, they recommended the option featuring several finishes of Milford Pink granite, which would have less contrast with the white granite coping of the Reflecting Pool and would create continuity with the existing historic elements of the stairs and flanking walls. They also recommended using Milford Pink granite for all the retaining walls and supported the alternative of capless walls, accentuating slightly the width and height of the seat walls flanking the plaza. For the retaining walls along the curved walkways, the Commission again recommended using Milford Pink granite to establish a unity of material with the rest of the memorial. The Commission recommended that these new curving walkways be paved in a way that is similar to the adjacent and secondary informal walkways, whether in concrete or asphalt.

For the linear walkways—the Elm Walks and the proposed paths along the Reflecting Pool—the Commission members strongly urged consideration of compacted gravel and stone dust as the paving system for these major pedestrian routes within the National Mall, commenting that these materials have desirable visual and auditory qualities as well as providing a softer surface for pedestrians. They noted the success of these materials in other world capitals and said that maintenance problems associated with the Mall's existing gravel pathways may be avoided through a well-detailed design, suggesting a depth of nine to twelve inches with a graduated substrate. Acknowledging that maintenance issues occur with all types of paving, the Commission members requested that the project team study and present this granular system in thorough technical detail if alternatives for hard pavement are to be considered. For the widths of the walkways, they recommended no more than 13'-4" along the Reflecting Pool; at the Elm Walks, they supported a fifteen-foot-wide walkway, possibly with a stone edge.

While expressing concern about the proposal to install lighting along the Elm Walks, the Commission members asked for further study of proposed lighting levels to minimize the intrusion on this particular part of the historic landscape which was not originally intended to be illuminated. They recommended the use of the more modern light fixture for its thin profile but asked that the standard be modified to be consistent with the simplicity of the luminaire. If a more historic fixture is considered appropriate, the Commission offered that an acceptable alternative would be the dark-sky compliant shaded fixture with a long arm, supporting bracket, and articulated base. In addition, the Commission requested that a comprehensive system of solar-powered lighting be studied for the Mall as a whole; this may result in a new design for the lighting elements. The Commission members expressed appreciation for the intention to manage the water features of West Potomac Park, particularly the Reflecting Pool, in a more sustainable way, rather than using municipal potable water as a source and a means for maintaining water quality. They supported the concept of using water drawn from the Tidal Basin and treated to the particular requirements of the Reflecting Pool as a reasonable approach, including the use of ground-water discharge from the World War II Memorial to offset losses from leakage and evaporation. However, the Commission requested that an energy analysis be undertaken for this portion of the project to ensure that in the final design, additional energy resources are not consumed in the name of sustainability.

The Commission appreciates the design team's thoughtful study of the comprehensive landscape design for this nationally significant location. The staff is available to assist you in resolving any outstanding design issues in order to achieve the funding and implementation of this project.

Sincerely,

/s/Thomas E. Luebke, AIA
Secretary

Margaret O'Dell, Regional Director
National Park Service, National Capital Region
1100 Ohio Drive, SW
Washington, DC 20242

cc: Peter May, National Park Service
Alan Ward, Sasaki Associates