With years of planning and work underground, Charleston city leaders expect to complete a slew of drainage improvements this year, and more are expected to begin.
City Council members were briefed about these plans Wednesday night by the Sustainability, Resilience and Stormwater department heads.
Here's an overview of the major projects:
Downtown's Spring/Fishburne: In progress
The $198 million project affecting about 500 acres of the peninsula is expected to be completed in 2023.
The area includes Hampton Park to the north, Meeting Street to the east, Charleston Center Drive to the south and Lockwood Drive to the west.
A mile-long tunnel beneath the Septima Clark Parkway is expected to be completed in June.
Downtown's Calhoun West: Planning in progress
A study team of North Charleston-based Davis and Floyd and Kansas-based Black and Veatch looked at an area that spans nearly 800 acres on the peninsula: Ashley River on the west, as north as Cannon Street, east to about King Street and south to the tip of the peninsula.
The study found that a deep tunnel and pump system would best address issues of tidal flooding and drainage improvement. A drainage project there is expected to be completed by 2030-2035. The estimated cost is about $200 million.
Downtown's Low Battery seawall raising: In progress
The $54 million project broke ground in December and includes raising the Low Battery wall along Murray Boulevard starting at the Coast Guard station on Tradd Street to the High Battery on East Battery Street.
The first phase is underway, running from Tradd Street to about Rutledge Boulevard. It is expected to be completed by the end of the year.
Downtown's Huger and King streets: In progress
City staff identified the Huger and King street intersection as a high-flood area. During heavy rain, about 2 feet to 4 feet of water will flood the roadway.
The area includes about 15 acres from Grove Street at the northernmost point, Ashley Avenue to the east, Sumter to the south and Hanover Street to the west.
An improvement plan is under design and construction is expected in June. The estimated cost is $1 million.
Downtown's Market Street: In progress
The area was once a tidal creek bed. Sudden thunderstorms and high tide can bring thigh-deep water.
The 59-acre area includes Concord Street from Calhoun Street to Clifford Street on the east, about Queen Street on the southern point, King Street on the west and Society Street to the north.
The $40 million drainage project is expected to be completed by 2023-2024. Completion is under review.
Downtown's brick arch replacements: Construction underway
Roughly 900 acres on the peninsula are impacted by failing brick archways under the city's streets. Once used for sanitation and drainage, the city is repurposing the archways to help drainage.
Of the 54,000 feet that need repair, 3,000 have been addressed so far. The total cost is estimated at $30 million.
The next area to be improved is about 1,400 feet on Limehouse Street. Draft plans have been completed.
West Ashley's Forest Acres: Project in progress
The area experiences flooding during heavy or repeated moderate rains, causing extensive damage to some homes and dangerous conditions for drivers and pedestrians in those neighborhoods. The stormwater pump station was outdated, outmoded and undersized. The city decided to go with a gravity system instead.
The area includes Marvin Avenue to the north, Old Town Road to the east, Paula Drive at its most southern point and west of Camellia Road as the westernmost part.
The $20 million project is expected to be completed by 2021-2022. The next phase is to improve the upstream area.
West Ashley's Church Creek: In progress
The area is historically old phosphate mines and marshes. It is about 80 percent developed, with mostly residential but some commercial development in place. So far, the city has spent about $3.7 million for stormwater runoff improvements. Work started in 2017.
The area includes Ashley River Road to the north, Glenn McConnell Parkway to the south, just east of West Ashley Park to the east and Church Creek to the west.
City staffers want to conduct a 200-acre inventory of the East Side, with a projected cost of $450,000. A proposal is expected to go before the City Council next month.
The city and county are partnering on an estimated $400,000 drainage study of the Dupont-Wappoo area in West Ashley. The area — Citadel Mall, Hazelwood area and neighborhoods near Dupont, Wappoo and Orleans roads — has seen worsening flood conditions on roadways, residential and commercial areas.
On James Island, the city and county are partnering on a study of the Central Park/Wambaw Creek area. The drainage study is in the planning stages and is expected to be completed by 2021. That work area includes Maybank Highway on the north, Folly Road on the east, Ellis Creek on the south and Riverland Drive and Woodland Shores Road on the west.
In West Ashley, the city is also studying the Windermere area.