Mean High Water


A project documenting the impacts of sea level rise & flooding across the South Carolina Lowcountry.
more

INSTAGRAM
NEWSLETTER
CONTACT





TABLE OF CONTENTS
01. Ghost Creeks of Charleston
02. A Primer on Flooding in Charleston
03. Elevations on MLLW Datum
04. Photographic Archive of Flooding
05.  Flooding Resources





USEFUL LINKS
National Water Level Prediction Service
NOAA Observed Water Levels
NWS Coastal Flood Event Database
Charleston TideEYE Dashboard





TROPICAL STORM DEBBIE
Stormwater Flooding associated with Tropical Storm Debby.
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.
Charleston City Market
Prioleau St.
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
Hurricane Idalia
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.

Hurricane Ian


Hurricane Irma
Peak Elevation: 9.92-ft MLLW (6.84-ft NAVD88)
Peak Time: 17:18 GMT (1:18 PM EST)
Maximum Rainfall: 4.53-in
Low Battery
Murray Blvd. at Rutledge Dr.
Murray Blvd.
Limehouse St at Murray Blvd.
Murray Blvd.
Galliard Center
Calhoun St. at Alexander St.
Meeting St.
Poulnot Ln.
White Point Gardens
Murray Blvd.
Meeting St.
Meeting St.
Water St.
Queen St.
Queen St.
Calhoun St. at Alexandar St.
White Point Gardens
Water St.
Murray Blvd.
King St.
Murray Blvd.
Queen St.


© 2025 All Rights Reserved