MEAN HIGH WATERFlooding in Charleston

About
Mean High Water (MHW) is a project documenting the impacts of sea level rise & flooding in and beyond the South Carolina Lowcountry. The title is in reference to the MHW tidal datum defined and maintained by the NOAA Center for Operational Oceanographic Products and Service.
The tides of Charleston Harbor and the Atlantic Ocean are increasingly encroaching into the natural and built environment of Charleston and the Lowcountry. The rate of increase in the number of coastal flood events is alarming. Approximately 53.3% of all coastal floods observed in Charleston Harbor from 1921 through 2022 have occurred since 2010. An average of 18.8 coastal floods occurred per year in the 1990s. In the 2010s, the annual average was 42.4 coastal floods2, an increase of over 200%.

MHW was started in 2020 by photographer and engineer Jared Bramblett. This is intended to be an evolving and collaborative documentation of the impacts of flooding. If you are interested in participating, please reach out.
 
Contact
Jared Bramblett
jaredbramblett@gmail.com


Disclaimer
All thoughts and opinions presented on this site are solely those of the author and are not necessarily those of any other organization.

All content presented on this site is copyrighted. To inquire about content usage, please submit a request.

© 2024 Jared Bramblett
Tidal Flood Records & Statistics
Charleston Harbor, Cooper River Entrance1

Coastal Floods (>7-ft MLLW)2
  1. 89 (2019)
  2. 75 (2023)
  3. 70 (2022)
  4. 68 (2020)
  5. 58 (2015)

Major Coastal Floods (>8-ft MLLW)2
  1. 7 (2020)
  2. 6 (2023, 2015)
  3. 4 (2021, 2019)
  4. 3 (2022, 2018)
  5. 2 (2009, 1947)

Peak Tide Crests (ft, MLLW)3
  1. 12.52-ft 09/22/1989 (Hugo)
  2. 10.23-ft 08/11/1940
  3. 09.92-ft 09/11/2017 (Irma)
  4. 09.86-ft 12/17/2023 (Nor’easter)
  5. 09.29-ft 10/08/2016 (Matthew)

Statistics current as of 08/31/2023

Sea Level Rise Trend (1901-2022)1

Sea level trend of 1.13-ft per 100 years (1901-2022)


References
1 Tidal Benchmark Station - Charleston, Cooper River Entrance, SC - Station ID: 8665530

2 NWS Coastal Flood Event Database

3 Advanced Hydrologic Predictions Service, Charleston, SC
2024/11/18 - Tidal Flooding
Peak Tide Elevation:
Peak Tide Time:

2024/09/17 - Tidal Flooding
Peak Tide Elevation:
Peak Tide Time:

2024/08/06 - Debby
Stormwater Flooding associated with Tropical Storm Debby.

2023/12/17 - Nor’easter Flooding
Peak Tide Elevation: 9.86-ft MLLW (6.74-ft NAVD88)
Peak Time: 16:54 GMT (11:54 AM EST)

  • The surge from the nor’easter was the 4th highest tide on record in Charleston Harbor, and it exceeded the predictions by approximately 1.6 feet.
  • It was the highest tide not associated with a tropical cyclone ever recorded in Charleston.
  • There were approximately 3-6 inches of rainfall across the peninsula at the same time, resulting in compound flooding across the City.
  • In 2023, we’ve seen the 4th and 6th highest tides ever recorded in the harbor.
  • It’s the 6 tide this year to cross the major flood threshold, which is the 2nd most on record (there were 7 in 2020).
  • There are only 49 major tidal floods on record (1921 - present), and 20 of them have occurred since 2020.

Charleston City Market (State St. at Market St.)
Hasell St. at Washington St.
Prioleau St.
Charleston City Market
South Market St.
Charleston City Market
Market Pavilion Hotel (E. Bay St.)
North Market St.
Lodge Alley
Prioleau St.
North Market St
Charleston City Market
North Market St. at State St.
North Market St.
North Market St.
Washington St.
Charleston City Market
Charleston City Market
Charleston City Market (N. Market St.)
Charleston City Market
North Market St.
North Market St. at East Bay St.
North Market St.
East Bay St.
Vendue Range
Charleston City Market
North Market St.
French Quarter Inn, South Market St.
Charleston City Market
Charleston City Market
Vendue Range
North Market St.
State St. at South Market St.
Charleston City Market
North Market St.
Market St. at East Bay St.
North Market St.
North Market St. at Anson St.
Washington St. at Society St.
North Market St.
Charleston City Market
South Market St. at State St.
North Market St. at Church St.
South Market St.
Charleston City Market
Charleston City Market
2023/10/01 - Tidal Flooding


2023/09/29 Tidal Flooding


2023/09/27 Tidal Flooding


2023/09/17 - Stormwater Flooding

Morris St. at Jasper St.
Romney St at Nassau St.
Line St. at Aiken St.
Indian St.
Gordon St.
Strawberry Ln.
Morris St. at Felix St.
Meeting St. at Indian St.
Maple St.
America St. at Reid St.
Piedmont St.
Huger St.
Barre St. at Wentworth St.
Maple St.
Romney St. at Nassau St.
Simons St.
Maple St. at Ashley Ave.
King St.
America St. at Reid St.
Rutledge Ave. at Maple St.
Drake St. at Amherst St.
Morris St.
Kings Plaza
Kings Plaza
Calhoun St. at Rutledge Ave.
Calhoun St. at Ogier St.
Calhoun St.
Calhoun St.
Hannover St.
America St.
Morris St.
Halsey St.

2023/08/30 - Hurricane Idalia Storm Surge
Peak Elevation: 9.23-ft MLLW (6.09-ft NAVD88)
Peak Time: 00:18 GMT (08:18PM EST)

  • The surge during Hurricane Idalia’s passing of Charleston was the 5th highest on record in the Harbor, and it came within an inch of Hurricane Matthew’s surge in 2016.
  • The surge was driven by the timing and direction of Idalia’s path and it’s occurrence during a ‘king tide’ driven by August’s 2nd full moon. 
  • As of the end of August, we have seen 4 ‘major’ tidal floods in the harbor this year. With four month remaining, 2023 is already tide for 3rd in occurrences of major tidal floods in a year (tied with 2021 & 2019). 2020 holds the record for most major tidal floods (7). 


Morrison Drive
Union Pier
Society St. at Washington St.
Washington St.
Washington St.
Faber St.
North Market St.
High Battery
High Battery
High Battery
High Battery
High Battery
Water St.
Water St.
Water St.
Water St. at Church St.
Water St. at Church St.
Water St.
Water St. at Church St.
Church St.
S. Battery St.
S. Battery St.
S. Battery St.
Legare St.
Rutledge Ave.
Beaufain St.
Legare St.
Legare St.
S. Battery St.
S. Battery St.
Legare St.
Beaufain St.


2023/08/01 Tidal Flooding