The proposed improvements consist of raising South Whitney St. and West King St. above the FEMA flood elevation of 7.0’ NAVD88, replacing the existing box culvert (40-inch by 56 inch) at South Whitney with a single box culvert (48-inch by 96-inch) that doubles the hydraulic capacity. The project also includes reconstruction of the existing storm sewer system and its outfall at the box culvert on South Whitney Street.
The project goal to eliminate flooding during the 100-year FEMA flood event for West King St. and South Whitney St. by raising both roads at, or above, the 100-year floodplain elevation. In addition to the surge-driven FEMA 100-year flood event, during significant storm events, the box culvert at South Whitney St. restricts the flow of stormwater, creating flooding on the upstream side of the box culvert on South Whitney St. This flooding results in stormwater overtopping South Whitney St. and a portion of West King St. where these streets intersect making these streets impassable.
This is a high traffic area that is used heavily on a daily basis. By completing the drainage improvement project, residents of both the City. of St. Augustine and St. Johns County will benefit from the ability to drive through the street during a FEMA 100- Year Floodplain.