It is a necessity to construct a 1.55 mile long dam and a 2.22 mile long dirt structural wall to protect against coastal inundation along the Potomac. A balance between land structure and water depth, the dam will span Persimmon Point to Aqualand Park. This structure has a one way tesla valve placed along current shipping routes allowing ships, wildlife, and debris to pass through the dam unaltered. The valve would protect against extreme tides and storm surges from affecting upstream Potomac. The dam has no moving parts and would require $1,394,977.15 in concrete and $11,721,600 in landfill labor to complete, protecting over $41,443,987,025 in residential Woodbridge, VA and DC. The 464,992.381 ft3 of concrete would create ecological detriments. However, the Potomac's destruction would be far larger a negative for human life, our economy and country, and our surrounding environment than the negatives the construction of the dam would ever cause. The regular affected tidal range is expected to be 12 feet by 2080 thus this dam would be 85 feet tall at its highest, and 85 feet long at its longest. The dam will be 25 feet above the water, with an emergency flow release at 20 feet.