A boathouse east of Key Bridge
I re-post below a statement to the Arlington 'Parkswatch' site. The statement discusses plans to build a boathouse and parking lot in the currently wooded area between the GW Parkway and the Potomac immediately downstream of the Key Bridge.
Mark Antell

After a lapse of several years, the National Park Service (NPS) is restarting the process of creating a boathouse on the Virginia shoreline by initiating an Environmental Assessment (EA) for the project in cooperation with the Arlington County government (see: https://parkplanning.nps.gov/p...cfm?projectID=13418). NPS will host a public meeting on the EA on Thursday, July 12, 2018 from 6:30 to 8:30 p.m. at Washington-Lee High School (see https://parkplanning.nps.gov/m...cfm?projectID=13418).

In 2012, NPS conducted a scoping meeting for an Environmental Impact Statement (EIS) for the project. See the scoping meeting materials and public comments at the above NPS website for more information about the meeting.

NPS has apparently discontinued the EIS process and is now planning to issue an EA. The EA will either recommend an EIS, fast-track the project by finding that the project has no significant environmental impact, or stop the project for the foreseeable future by supporting a "No-Action" alternative. Although details are not yet available, the EA may evaluate several "Action Alternatives" and recommend a "Preferred Alternative".

After the scoping meeting took place, the Arlington County Government purchased a forested parcel of land that is located east of Lynn Street in Rosslyn. This woodland is on high ground north of I-66 and the Custis Trail and south of the George Washington Parkway. The County's Department of Parks and Recreation (DPR) intends to level the forest so that it can construct a boathouse and perhaps a parking lot or structure on the site at taxpayer expense.

This County-owned site is not federal property. The NPS EA may therefore not address DPR's planned destruction of this natural area for which Arlington's taxpayers recently paid. Therefore, anyone who who would like to preserve the forest will need to inform the County Board of their opposition to this plan. The County Board still has the option of making the property a wooded County Park, rather than cutting down its trees to construct a boathouse.

To connect the main boathouse with the waterfront, the County or the NPS may construct a new bridge over the GW Parkway. The EA would address this bridge, whose construction would destroy more trees.

The County or the NPS would also construct another boat-related facility near the waterfront. Construction of this facility would pave over a site near the river and the Potomac Heritage Trail, which would probably also be paved. As this would destroy trees within the river's Resource Protection Area, the EA would address this facility. The facility may or may not be visible from the GW Parkway, but would certainly adversely impact the view of the shoreline from Key Bridge and from Theodore Roosevelt Island.

The NPS website does not presently describe the alternatives that the EA will evaluate. However, the alternative above, which Arlington's DPR prefers, would almost certainly have a far greater adverse impact on the natural environment than would any other alternative.

If you are interested in this project and its many adverse environmental impacts, attend the July 12 meeting and submit comments to NPS. The NPS website does not presently contain a comment page; this will probably appear in the near future.

Bernie Berne
Posts: 319 | Registered: December 08, 2002Reply With QuoteReport This Post
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I previously posted a note from Bernie Berne, a local environmentalist, on the Rosslyn Boathouse project. I attach below perspective from Suzanne Sundburg, another Arlington environmental advocate.
Mark Antell


Subject: Two trails disrupted, wetlands to be dredged for new boathouse, dock, etc.

Not sure whether you have heard about the new boathouse to be constructed on National Park Service land across from Roosevelt Island. For a quick overview, see https://www.arlnow.com/2018/06...-site-for-boathouse/

There are 4 alternatives (A–D), however NPS has selected the alternative that is preferred by Arlington County — "Alternative C." This option also happens to be the most environmentally damaging of the 4 options. It will involve dredging of 58,000 sq ft of wetlands along the Virginia shoreline of the Potomac River, just across from the northern tip of Theodore Roosevelt Island, which has been having some shore erosion problems on the Virginia side of the island where the old causeway used to be (and sensitive marsh and wetlands are located).

Dredging is incredibly damaging. It can readjust river flow in a way that causes unintended impacts, including erosion. In addition to the dredging, NPS states that 1.5 acres of trees and vegetation next to the Potomac shoreline will be cleared in the lower section. Two popular trails also will be interrupted by the development plan and must be rerouted. The loss of trees and vegetation in the upper section, which belongs to Arlington County, will be significant. Many trees near both trails are to be cleared and will be replaced with an auxiliary building to support the boathouse, a parking lot, and an access road.

In short, what has been a largely, green, leafy oasis next to an intensively developed area (Rosslyn) will be destroyed. I'm not against adding a boathouse for users in Arlington. However, this site is unsuitable. Alternative D — the Gravelly Point site – is an acceptable alternative that doesn't require dredging, additional parking infrastructure, the massive loss of trees and vegetation, or the interruption of two popular trails.

Below are some details that might be useful.

Upper/Lower Rosslyn Environmental Impacts
The National Park Service (NPS) owns the lower part of the site in the option it prefers — Alternative C, "Combined Upper and Lower Rosslyn Sites" — which also happens to be Arlington's preferred option. This area comprises natural, forested, passive-use, riparian land through which two popular trails transit (the unpaved Potomac Heritage Trail and the paved Mt. Vernon Trail). Option C is the most environmentally destructive alternative of all four alternatives described in the NPS Environmental Assessment (EA).

Also according to the EA, the Rosslyn site would entail significant dredging activity along the sensitive shoreline near Roosevelt Island at the Lower Rosslyn Site:

Approximately 58,000 SF of excavation and dredging would be required to achieve at least 3.3-foot depth in this location to accommodate depth required for coaching launch boats and rowers to avoid underwater obstructions. See pp. B-1 and B-2 in APPENDIX B: WETLAND STATEMENT OF FINDINGS (starts on p. 158 of the PDF). https://parkplanning.nps.gov/d...418&documentID=89109

Area to Be Dredged for Option C - Rosslyn Boathouse.jpg

58,000 sq ft of wetlands to be dredged for Option C (see the area outlined in red)

Why is dredging so damaging? Because this area is considered to hold sensitive wetlands:

Wetlands on the lower Rosslyn site are shallow water riverine wetlands in the Potomac River, where the dock would be placed, and dredging is proposed to allow access to the docks…. Functions of this wetland include nursery habitat in the SAV [submerged aquatic vegetation] and providing shallow water and benthic habitat for aquatic species, including fish and macroinvertebrates found in the Potomac River. See p. B-8 in APPENDIX B: WETLAND STATEMENT OF FINDINGS. https://parkplanning.nps.gov/d...418&documentID=89109

Vegetation clearing, regrading and dredging under alternatives B and C would adversely impact wetlands and vegetation. See p. 3 of the June 2018 Arlington County and Vicinity Boathouse Environmental Assessment PDF.

Construction of a boathouse facility and the installation of docks and soft launch sites, as well as dredging that could be required at one of the sites, could affect shallow water riverine wetlands associated with the shoreline of the Potomac River that often support submerged aquatic vegetation (SAV). In addition, a change in the hydraulics of the river associated with the installation of the rowing facility’s docks could potentially remove sediment from some areas and deposit it at different locations, which could also affect riverine wetlands. See p. 13 (marked as p. 3) of the June 2018 Arlington County and Vicinity Boathouse Environmental Assessment PDF.

Additionally, dredging may be required near potential underwater archeological resources, which would disturb the river bottom and potentially affect archeological resources. See p. 16 (marked as p. 6) of the June 2018 Arlington County and Vicinity Boathouse Environmental Assessment PDF.

The 2018 Draft Cultural Landscape Report and Environmental Assessment for Theodore Roosevelt Island shows where existing wetlands on the Virginia side could be negatively impacted by the upstream wetland dredging for the boathouse and dock: http://npshistory.com/publicat...his/clr-ea-draft.pdf

Wetlands and Marsh Environmental Assessment of Roosevelt Island.jpg

Not only are wetlands vital to a healthy ecosystem and environment, their preservation is also of critical importance in flood mitigation and control:

Wetlands function as natural sponges that trap and slowly release surface water, rain, snowmelt, groundwater and flood waters. Trees, root mats and other wetland vegetation also slow the speed of flood waters and distribute them more slowly over the floodplain. This combined water storage and braking action lowers flood heights and reduces erosion.
Wetlands within and downstream of urban areas are particularly valuable, counteracting the greatly increased rate and volume of surface- water runoff from pavement and buildings. https://www.epa.gov/wetlands/w...e-wetlands-important

Though the NPS Environmental Assessment for the boathouse downplays the loss of trees and vegetation, this appears to be due to the fact that much of the forested areas to be cleared will be on Arlington County property. The cumulative degradation to the riparian area (in both upper and lower sections) from the loss of trees/vegetation, land disturbance and increase in impervious surfaces will be significant and will result in increased stormwater runoff containing sediment and contaminants (including petrochemicals from the parking lot and road) that will run directly into the adjacent Potomac River.

Preparation of the site for the 14,000 SF boathouse would require clearing and conversion of some currently vegetated areas on the site. Vegetation including shrubs, turfgrass, and other understory vegetation would be disturbed and removed temporarily during construction activities. Additionally, the placement the boathouse, rigging area/apron, and realigned Potomac Heritage Trail, would permanently remove trees, shrubs, turfgrass, and other understory vegetation and convert these areas to impervious surface or pervious pavement. Because the boathouse has not been designed, it is not possible to identify the numbers, types, or location of trees, shrubs, turfgrass, and other vegetation that would need to be removed to accommodate the boathouse and dock. However, up to 1.5 acres of vegetation clearing may be required during the construction period. (Note: This only addresses the loss of trees in the lower portion of the site. See p. 65 in the Assessment document at https://parkplanning.nps.gov/d...18&documentID=89109.)

Also, Alternative C [same for Alternative B] would require paving over a portion of the Potomac Heritage Trail — this unpaved NPS trail runs along the Potomac River shoreline from Rosslyn to the American Legion Bridge. And alternative C calls for paving over and rerouting a portion of the very popular Mount Vernon Trail. The upper portion of the site belongs to Arlington Count, for which there has been no separate environmental impact analysis, even though Alternative C will result in a significant loss of trees and vegetation that will be replaced with impervious surfaces. Both trails would be closed for up to 1 year. Construction materials and equipment would be stored in the parking lot for Roosevelt Island for up to 1 year, making it difficult for visitors to have access to the island for a significant period.

Alternative D — the Gravelly Point option, which the county doesn't support — requires NO dredging and NO addition of a new parking lot next to the Potomac River. It also requires the sacrifice of only a few trees and a modest amount of vegetation. This area is already developed and is easily accessible from the parkway with sufficient existing parking facilities.

Suzanne Smith Sundburg
Arlington, Va.
Posts: 319 | Registered: December 08, 2002Reply With QuoteReport This Post
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