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Low Battery Restoration Project
Phase I - Tradd Street to Ashley Boulevard
Tropical Storm Irma, Sep. 11, 2017
Cover photo by Jared Bramblett
Historic Background
Changing Landmass
This map by J. H. Colton & Co. shows the extents of the City of Charleston in 1877, thirty years before the Low Battery seawall was constructed on filled land.
By the end of 1911, 47 acres had been reclaimed and was divided into 191 residential building lots.
Slide the bar to view the changing land mass from 1877 (left) to 1919 (right).
Original Seawall Design
The Low Battery was constructed as part of a large land reclamation project undertaken in two phases:
- The first section (1909 - 1911) extended from Tradd Street to King Street.
- The second phase (1917 - 1919) extended from King Street to "the Turn" at the intersection with East Battery Street.
Map of the Battery seawall
The concrete wall of the Low Battery was constructed on a timber deck supported by timber pilings. The seaward face of the Low Battery is skirted with concrete panels attached to timber sheeting and batter piles. Together this formed a retaining wall system to retain the landside fill.
Cross-section design of the existing seawall (left), seawall excavated during reconstruction of the Turn (center), and construction of the existing Low Battery seawall (right).
Identifying the Problem
Existing Condition
The seawall has withstood many storms, but the damage is clearly evident in the large cracks, crumbling concrete, exposed rebar, and eroded base along the entire length of the Low Battery seawall.
Photos by: Johnson, Mirmiran & Thompson (JMT)
Construction
Phase I - Tradd Street to Ashley Boulevard
Map showing the Low Battery Restoration by phase of construction
Construction on the Low Battery Restoration Project began with Phase I, extending from Tradd Street to just beyond Ashley Boulevard. Phase I construction started in December 2019 and is now complete and open for public enjoyment. Construction of Phase II extends from the completed Phase I to just before Limehouse Street, and work is expected to take about one year.
View the slideshow below by clicking on the arrows to the right and left.
Results
Quantifying the Increased Protection from the Tide
Raising the height of the seawall 1.8', an elevation that will match the height of the High Battery seawall, will have a significant benefit to the immediate area during storm events. Only two storms in recorded history have created a storm surge that would overtop the new seawall. Hurricane Hugo generated a whopping 20' storm surge in 1989, which is 8' above the new seawall height! (A storm in 1940 would have just overtopped the new wall by less than one foot.) In the unfortunate event the river overtops the new seawall or the area is hit with a large amount of rain at high tide, the increased size of the newly installed storm drains means the Battery will drain quickly when the tide subsides. King Tides alone will not be a problem along the Battery because all outfalls will have valves to keep the tidal water in the Ashley River where it belongs.
The existing seawall compared to the new seawall.
The completed project - Murray Boulevard at Ashley Avenue. Photo by Jerry Martin
The completed project - Murray Boulevard at Tradd Street. Photo by Jerry Martin
Content provided by the City of Charleston Department of Stormwater Management and Johnson, Mirmiran & Thompson.