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Finding of No Significant Impact


The National Park Service has issued a Finding of No Significant Impact (FONSI) for the Rehabilitate Tidal Basin and West Potomac Park Seawalls Environmental Assessment (EA). The FONSI, which describes the selected action and explains why the plan will have no significant effects on the natural, cultural, or human environment, concludes the planning and environmental compliance process in the effort to rehabilitate the Tidal Basin and West Potomac Park seawalls.

The EA evaluated the potential impacts of the seawall rehabilitation on the surrounding environment and suggested alternatives and mitigations. After evaluating two alternatives, the NPS selected and approved the preferred alternative, which will rehabilitate the seawalls to include the following actions:

- Rehabilitate approximately 6,800 linear feet of seawall along West Potomac Park and portions of the Tidal Basin to extend the seawall's life by approximately 100 years.

- Rebuild the seawall to include a pile-supported platform foundation that will prevent the seawall from settling and support height extensions of the wall if needed due to future rising sea levels or increasing storm surge elevations.  


- Increase the seawall height 4.75 feet within the Tidal Basin and 5.50 feet along West Potomac Park to account for wind and wave conditions along the Potomac River.

- Salvage and reuse stones from the historic wall in the rehabilitated seawalls.

- Repair, or replace, and widen walkways around the Tidal Basin from eight to twelve feet wide to provide smoother, more accessible connections to other pathways.

The process now moves on to the awarding of a design-build contract for the construction, with work expected to begin in the summer of 2024. Both the planning and environmental compliance process and the construction of the seawall rehabilitation project are funded by the Great American Outdoors Act.
 
Document Content:
Coastal Modeling Report   (6.3 MB, PDF file)
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