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.

© 2023 Jared Bramblett
Tidal Flood Records & Statistics
Charleston Harbor, Cooper River Entrance1

Coastal Floods (>7-ft MLLW)2
  1. 89 (2019)
  2. 70 (2022)
  3. 68 (2020)
  4. 58 (2015)
  5. 55 (2016)

Major Coastal Floods (>8-ft MLLW)2
  1. 7 (2020)
  2. 6 (2015)
  3. 4 (2023, 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. 09.29-ft 10/08/2016 (Matthew)
  5. 09.23-ft 08/30/2023 (Idalia)

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
Mean High Water is currently being updated. Look for past flood events to be added to the archive over the next few weeks.    
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.


2023/06/04 - Tidal Flooding

Peak Elevation: 8.37-ft MLLW (5.23-ft NAVD88) 
Peak Time: 01:24 GMT (09:24PM EST)

S. Market St.
City Marina
E. Battery St.
Gadsden St.
City Marina
Ashley Ave. (MUSC)
Lockwood Dr.
Gadsden St.
Wentworth St.
N. Market St.
City Marina
Gadsden St.
Ashley Ave.
Beaufain St.
Gadsden St.
Beaufain St.
Wentworth St.
Beaufain St.
Beaufain St.
Gadsden St.
Gadsden St.
Wentworth St.
Atlantic St.
Ashley Ave.
Gadsden St.
Beaufain St.


2021/11/08 Tidal Flooding

Gadsden St. at Wentworth St.
Barre St.
Gadsden St. at Wentworth St.
Gadsden St.
America St.
America St.
Wentworth St.
Gadsden St.
Morrison Dr.
Morrison Dr.
Morrison Dr.
Gadsden St.
Gadsden St. at Wentworth St.
Wentworth St.
Cooper St.
Gadsden St.
N. Hannover St.

2021/11/06 Tidal Flooding

Ashley River Bridges (US17) at Lockwood Dr.
Morrison Dr.
Morrison Dr.
Lockwood Dr. at Broad St.
Bee St.
Morrison Dr.
Johnston St.
N. Hanover St.
Hagood Ave.
Broad St. at Lockwood Dr.
Line St. at Hagood Ave.
Lockwood Dr.
Hagood Ave.
Ashley River Bridges (US17) at Lockwood Dr.

2021/11/05 Tidal Flooding

Calhoun St. at Courtenay Dr.
Calhoun St. at Courtenay Dr.
The Harborage at Ashley Marina
The Harborage at Ashley Marina
Calhoun St. at Courtenay Dr.
The Harborage at Ashley Marina
Broad St. at Lockwood Dr.
Broad St. at Lockwood Dr.
Lockwood Dr. at Broad St.
The Harborage at Ashley Marina
The Harborage at Ashley Marina
Lockwood Dr.
City Marina
Under the James Island Connector

2021/03/18 Stormwater Flooding

Line St.
Line St.
King St. at Huger St.
King St. at Huger St.
Sheppard St. at Rutledge Dr.
Line St.


2020/11/15 Tidal Flooding

Fishburn St. at Hagood Ave.
Lockwood Dr. at US17
Hagood Ave.
Hagood Ave. at Fishburne St.
Hagood Ave.
Line St. at Hagood Ave.
WestEdge
Fishburne St. at Hagood Ave.
Spring St. (US17) at Lockwood Dr.
Bogard St. at President St.
WestEdge
Line St. at Hagood Ave.
Hagood Ave.
Bogard St.


2020/10/19 Tidal Flooding


S. Battery St. at E. Battery St.
S. Battery St. at E. Battery St.
S. Market St.

2020/09/25 Stormwater Flooding

President St. at Line St.
President St.
Beneath I-26
President St.
Fishburne St.
President St.
Fishburne St. at Larnes St.
Huger St. at King St.
Fishburne St. at Killians St.
Fishburne St. at Killians St.
President St. at Septima P. Clark Expressway (US17)
President St.
Ashley Ave.
Sumter St. at Ashley Ave.
President St. at Line St.
Line St.
President St. at Fishburne St.
Ashley Ave. at Sumter St.
William Enston Homes (Huger St. at King St.)
Fishburne St. at Orrs Ct.