A project documenting
Sea Level Rise & Flooding in the Lowcountry

01 OVERVIEW ︎︎︎
02 LATEST ︎︎︎   
03 ARCHIVE ︎︎︎

Mean High Water (MHW) is a project documenting the impacts of sea level rise 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%.

This project was started by photographer and engineer Jared Bramblett in 2020. It is intended to be an evolving and collaborative documentation of the impacts of rising seas and how communities are adapting to them. 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.

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Jared Bramblett

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

Charleston Harbor, Cooper River Entrance1

Coastal Floods (>7-ft MLLW)2
89 (2019)
68 (2020)
58 (2015)
55 (2016)
46 (2017)

Major Coastal Floods (>8-ft MLLW)2
7 (2020)
6 (2015)
4 (2019)
3 (2018)
2 (2009)

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 

22 of the 36 (61%) major flood tides on record have occurred since 2015.3

Statistics current as of 1/31/2021


1Tidal Benchmark Station - Charleston, Cooper River Entrance, SC - Station ID: 8665530
This is the homepage for the Charleston Tidal Benchmark, which serves as the main tide gauge referenced for tide levels in the Charleston region. The tidal datums (e.g. MLLW, MHW, MHHW) for Charleston are presented here. Lunar tide levels predictions can be found here, and the database of historic tide levels can be accessed here.

2NOAA Coastal Flood Event Database
This is a database maintained by the NOAA Coastal Services Center that tracks coastal flooding in Charleston and Savannah. It is referenced often throughout this site,  particularly when discussing the number of coastal floods that have occurred in Charleston Harbor.

3Advanced Hydrologic Prediction Center, Charleston, SC
Forecasts for water levels at the tidal bench mark based on meteorological predictions are presented here.

Surge Protection for Charleston?

June 2020 - Jared Bramblett

The comment period on the US Army Corps of Engineers Coastal Flood Risk Management Study (surge protection wall) ends this Friday (06/19/2020). All comments submitted prior to the deadline will be incorporated into the project documentation and addressed by the Corps. I encourage you to read the report and consider submitting comments. It is important that comments are submited by Friday so that we can hopefully influence the outcome of this project. Note that the comment application limits comments to 1000 characters. If your comments are longer, you can submit them as multiple comments or email them to

I created the visualization studies below for the Historic Charleston Foundation to develop a point of reference and scale for the proposed wall’s impacts around Peninsular Charleston.This is a significant project that is going to impact how we live on the peninsula and interact with our environment. Ultimately, I believe we do need some form of perimeter protection. However, we need to carefully look at this project and how it interacts with our natural and man-made systems holistically. The City's estimated financial obligation is significant, so the project is likely to affect many aspects of City government. We need to ensure that the City will be able to continue to provide services and implement other improvements (storm drainage, parks, etc.) to improve quality of life for the City's residents. Climate change and sea level rise are going to present enormous challenges moving forward, and we need to look at innovative ways to mitigate their impacts.

There’s a lot to dive into in the report. Here are important points that I think should be considered:
  • It is paramount that the project protect the area from tidal flooding events (’King Tides’ or ‘sunny day flooding) associated with sea level rise.
  • The alignment and height of the protection should be carefully analyzed and considered. Is protection to 12-feet appropriate, or should we look at different elevations? Should the wall be placed within existing high ground, or should it be in the marshes and rivers that surround the peninsula?
  • The project should be investigated in a holistic way that aims to make us resilient to future challenges associated with climate change and sea level rise. A robust system that has multiple protections from single points of failure is essential.
  • The project should have multiple uses and benefits. Recreation facilities should be incorporated into the permitier protecton wherever feasible. The current alignment along the Ashley River provides a significant opportunity to increase public access to the riverfront.
  • The perimeter protection is going to impact how stormwater runoff flows and drains within the wall. Surface storage of runoff and other nature based solutions will help make stormwater management within the wall more manageable and resilient and should be considered wherever feasible.
  • The Dutch Dialogues Charleston presents concepts for managing surface water runoff, coastal protection, and groundwater in a cohesive manner. It’s important tha this project consider and incorporate practices to mitigate adverse impacts to groundwater.

I encourage you to submit comments during this period and to stay engaged as this project progresses. There will be another public comment period in January of 2021.
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