[Federal Register Volume 74, Number 190 (Friday, October 2, 2009)]
[Notices]
[Pages 50987-50988]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-23550]


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DEPARTMENT OF THE INTERIOR

National Park Service


National Mall and Memorial Parks, Washington, DC; Notice of 
Availability of a Finding of No Significant Impact for the Proposed 
West Potomac Park Levee Project

AGENCY: Department of the Interior, National Park Service.

ACTION: Notice of Availability of a Finding of No Significant Impact.

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SUMMARY: Pursuant to the National Environmental Policy Act (NEPA) and 
National Park Service (NPS) NEPA guidelines, NPS prepared and, from 
January 30 to March 2, 2009, made available for a 30-day public review 
an Environmental Assessment (EA) evaluating the potential impacts of 
proposed improvements to the existing West Potomac Park Levee System 
which extends from 23rd Street, NW., to the grounds of the Washington 
Monument in Washington, DC. The goal of this project is to improve the 
reliability of the existing levee in order to meet the current post-
Hurricane Katrina standards for flood protection as required by the 
U.S. Army Corps of Engineers (USACE) and the Federal Emergency 
Management Agency (FEMA). The existing levee protects much of the 
monumental core and large portions of downtown Washington, DC.
    After the end of the 30-day public review period, the NPS selected 
for implementation, the preferred alternative as described in the EA, 
and determined it will not have a significant impact on the quality of 
the human environment and that an Environmental Impact Statement is not 
required. In making that selection and determination, the NPS 
considered the information and analysis contained in the EA and the 
comments received during the public review period. The NPS has 
accordingly prepared a Finding of No Significant Impact (FONSI) for the 
proposed West Potomac Park Levee Project. The FONSI is also accompanied 
by an errata sheet that corrected some minor inaccuracies and updated 
some information. The errata did not result in any changes in the 
overall findings of the EA and had no bearing on its determination of 
no significant impact.

FOR FURTHER INFORMATION CONTACT: Mr. Doug Jacobs, Deputy Associate 
Regional Director for Lands, Resources and Planning, National Capital 
Region, National Park Service, 1100 Ohio Drive, SW., Washington, DC 
20242, by telephone at (202) 619-7025 or by e-mail at [email protected].

SUPPLEMENTARY INFORMATION: Since the Potomac Park levee was constructed 
in the late 1930's, the levee system has relied upon a temporary 
earthen closure being built across 17th Street in the event of a flood 
emergency. Based on new policies since Hurricane Katrina (33 CFR 
208.10), the USACE has deemed the temporary 17th Street closure 
unreliable and consequently gave the levee an unacceptable inspection 
rating. For this reason, FEMA's most recently proposed 100-year 
floodplain map for this area reflects a 100-year flood event as if the 
currently-designed 17th Street closure did not exist (44 CFR part 67, 
72 FR 54631-54635). This new mapping would place portions of southeast 
and downtown Washington, DC, including the monumental core, within the 
100-year flood insurance rate zone. The placement would require 
additional flood insurance and/or costly upgrades to comply with 
building standards for those facilities that would fall within the new 
100-year floodplain. In addition, a number of projects that are 
currently in development on the National Mall would need to be revised 
and could be delayed in order to comply with these building codes. At 
the District of Columbia's request, FEMA agreed to delay issuance of 
the new floodplain map until November, 2009, in order to allow the 
District and the NPS time to design and implement a solution that will 
reliably stop a 100-year flood at 17th Street, NW., and therefore make 
re-mapping unnecessary.
    In addition, the USACE requested that the solution be designed in 
such a manner as to allow for easy modification to meet the higher 
level of protection authorized by Congress in 1936 but never funded. 
The congressionally authorized level of protection is roughly 
equivalent to a 187-year storm. The District and NPS agreed that any 
improvements to the levee should be consistent with the current 
authorization so that the congressionally authorized level of 
protection can ultimately be achieved once funding is appropriated.
    The EA evaluated five alternatives, all of which incorporate a 
permanent structure from Overlook Terrace in Constitution Gardens to 
the west side of 17th Street and another permanent structure on the 
east side of 17th Street which extends into the natural rise of the 
Washington Monument Grounds. The intervening space across 17th Street 
will have footings designed to receive a temporary post and panel 
closure system that would be deployed only during a major flood event. 
The permanent structures on either side of 17th Street will be a 
combination of earthen berms and concrete walls/embankments which will 
be clad in stone during a subsequent phase of the project. Since full 
funding for the entire project was not certain, all of the alternatives 
in this EA are presented in a phased approach.
    The NPS identified Alternative 1B as its Preferred Alternative and 
has selected it for implementation. During the completion of this EA, 
it became apparent that considerable costs and time of construction 
and, therefore, time of disturbance to the National Mall and visitors, 
could be avoided if the levee at 17th Street was constructed to the 
higher level of protection initially, if funding would be available. 
Under Phase 1 of the alternative, a levee closure structure will be 
constructed at 17th Street, approximately 253 feet south of the 
centerline of Constitution Avenue, NW. The closure structure will 
consist of two symmetrical curved concrete flood walls built to the 
height of the Congressionally-authorized solution and set back 
approximately 23 feet to the east and west of 17th Street. The flood 
walls will require the re-grading of both the northwest corner of the 
Monument Grounds as well as the eastern edge of Constitution Gardens 
between the Overlook Terrace and 17th Street. Tree planting and final 
landscaping will also be completed as the first phase of the project. 
In the second phase of implementation, the remaining visible sections 
of the levee wall at 17th Street will be clad in stone to match the 
historic character of the adjacent cultural landscapes and historic 
resources. The cladding will enhance the aesthetic quality and 
character of the landscape to mitigate against adverse effects 
associated with concrete walls.
    Phase Two includes a pedestrian path and additional landscaping. 
Improvements to the other parts of the Potomac Levee will also occur as 
part of the second phase of implementation since the existing 
conditions at 23rd Street, NW. and the Reflecting Pool do not meet the 
Congressionally-authorized level of protection. At the southwest corner 
of 23rd Street and Constitution Avenue, NW., portions of the site will 
be re-graded and raised by approximately one to two feet. Along

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the levee that runs parallel to the Reflecting Pool, several hundred 
feet of low spots will be filled to bring the height of the levee to 
the Congressionally-authorized level of protection.
    This alternative will be further developed into preliminary and 
final designs which will be subject to additional review by the 
National Park Service, the National Capital Planning Commission and the 
Commission of Fine Arts.
    The FONSI and other documents related to this action are available 
for review on the NPS's Planning, Environment, and Public Comment 
(PEPC) Web site at http://parkplanning.nps.gov/projectHome.cfm?parkID=427&projectId=22260. You may also request a hard 
copy at (202) 619-7025.

    Signed on July 29, 2009.
Margaret O'dell,
Regional Director, National Capital Region.
[FR Doc. E9-23550 Filed 10-1-09; 8:45 am]
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