Flooding & Sea Level Rise in the SC Lowcountry

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 45% of all coastal floods observed in Charleston Harbor from 1953 through 2020 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. It is intended to be an evolving and collaborative documentation of the impacts of flooding. If you are interested in participating and submitting to the project, please reach out. All content on this site is copyrighted. If you are interested in using any content, please submit a request.

Jared Bramblett

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

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Charleston Harbor, Cooper River Entrance1

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

Major Coastal Floods (>8-ft MLLW)2
7 (2020)
6 (2015)
4 (2021)
4 (2019)
3 (2022, 2018)

Peak Tide Crests (MLLW)3
09/22/1989 - 12.52-ft (Hugo)
08/11/1940 - 10.23-ft (Unnamed)
09/11/2017 - 9.92-ft (Irma)
10/08/2016 - 9.29 (Matthew)
01/01/1987 - 8.81-ft 

29 of the 43 (67.4%) major flood tides on record have occurred since 2015.3

Statistics current as of 01/01/2023


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

2NWS Coastal Flood Event Database

3Advanced Hydrologic Prediction Service, Charleston, SC 

2022 - A Review of the Year in Flooding

January 2, 2023

2022 seemed like a year of flooding extremes in Charleston. We spent about eight (8) month in abnormally dry conditions, and five (5) of those months were considered moderate drought. We typically average around 45-inches of rainfall a year, and we ended the year with a total of 39.2-inches. Reviewing NWS data for the peninsula, there have been three years since 2014 with below average rainfall (2014, 2019, & 2022), and 2022 was the driest. However, that does not mean that we did not see significant flood events throughout the year.

There were several instances of rainfall-induced stormwater flooding, particularly during the summer months. Reviewing the NWS Coastal Flood Event Database, it (unofficially) looks like we saw 70 tidal flood events over the year, which is the 2nd most on record (we saw 89 in 2019). We had the 13th and 14th highest tides on record in November and December, respectively. The NWS defines tidal flooding in Charleston as tides reaching or exceeding 7 feet above the mean lower low water (MLLW) datum, with tides reaching 7.5-ft MLLW as moderate flooding and 8.0-ft MLLW as major tidal flooding. We saw 70 tides reach flood stage (2nd most on record), 22 tides reach moderate flood stage (3rd most on record), and 3 tides reach major flood stage (4th most on record).  Tropical Storm Colin (July) and Hurricane Ian (September) both passed very close to Charleston, and we also saw tidal flooding impacts from Hurricane Nicole (November). Ian, by far, had the greatest impact on Charleston (including high winds and significant stormwater flooding across the City), but we fortunate to avoid the impact of surge due to the storm’s path. Below is a visual recap of flooding throughout the year.

© 2022