Developing Sam’s Spit would defy reality of sea level rise

The narrow neck of Capt. Sam's Spit between the Kiawah River and the Atlantic Ocean. (Brad Nettles/File)

The level of the sea is rising. There are several reasons for sea level rise, but it is predominantly due to the melting of the Greenland and West Antarctica ice sheets, and the world’s mountain glaciers.

Most impactfully, the increase in temperature of the upper 3,000 feet of the ocean’s water causes expansion, and adds significantly to our rising seas. Locally, sea level rise is partly responsible for the extensive erosion on the South Carolina coast. Compounding the situation are engineering activities on the beaches, including the construction of seawalls, groins, and jetties.

The current global rate of sea-level rise is one to one and a half feet per century. According to the United Nations Intergovernmental Panel on Climate Change (IPCC), the sea level rise rate should begin to accelerate significantly in 20 to 30 years, and by the year 2100, we are likely to have a global sea-level rise of three feet.

In the context of the expected rise in sea level along the S.C. coast and an already widespread erosion problem along the state’s shorelines, now is not the time to initiate new beachfront developments. Now is the time to plan for responding to the sea level change and to discourage major beachfront developments that will only make future response more difficult and costly.

One such major development is proposed for Captain Sam’s Spit on Kiawah Island. Developers want to build 50 houses on this 150-acre barrier island spit. Like almost all of the 2,200 barrier islands around the world, Captain Sam’s Spit is eroding on both sides. Also, like other barrier islands, there are periods of accretion (sand building up) as well as erosion, with erosion being predominant.

One of the problems with Captain Sam’s Spit is the very narrow neck that attaches the spit to Kiawah Island. As sure as the sun sets every evening, the spit will break off in future storms and a new inlet will form, isolating any development. Over all, development on the spit will result in great costs to federal, state and local taxpayers, who will end up footing the cost to fill in the new inlets and protect the development using beach replenishment and probably eventually seawalls.

As it stands now, Captain Sam’s Spit is a relatively rare undeveloped recreational area and should remain so. Since there are currently no buildings there, erosion is not a problem to be solved.

A proposed state regulation, put forward by Sen. Ray Cleary, R-Georgetown, would establish a permanent baseline along the entire coast, a recommendation of the state’s Blue Ribbon Committee on Shoreline Management. Rather than being re-measured and reset every decade, the recommended method is to have the baseline set permanently, so that it would never be moved seaward, regardless of any accretion or replenishment of the beach beyond it.

Until recently, Kiawah Development Partners (KDP), the out-of-state developers who want to build on Captain Sam’s Spit, have failed to obtain the requisite permits from the state Department of Health and Environmental Control (DHEC), a move approved by the S.C. Supreme Court. Now, KDP is co-opting Sen. Cleary’s good legislation that could protect our entire state. To that end, the development group has lobbied heavily to seek a delay in setting this permanent baseline.

Rather than setting it now, based on existing data, KDP wants the Legislature to pass S-139, with an amendment from Sen, Paul Campbell, R-Berkeley, to delay the procedure and to wait for another data cycle before setting the recommended permanent baseline. The developers have not made clear what they expect by delaying it, but the possibility may be that if enough time passes, more sand would accrete on the spit, and they would then (temporarily) have more room to build a road to their proposed development.

Basically, there is nothing scientifically valid about delaying setting a permanent baseline while new data is collected, because beaches erode and accrete regularly.

It is a shame that one senator, on behalf of one developer of a mile of beachfront, is jeopardizing the entire state’s beachfront management program that includes the permanent baseline recommended by the Blue Ribbon Committee. Even though shorelines in South Carolina occasionally accrete, as may be happening on Captain Sam’s Spit, the overall trend for South Carolina beaches (including the spit), as in 90 percent of the world’s shorelines, is erosion.

Sea level rise and storms will exacerbate the retreat. Setting a permanent baseline based on current data for the S.C. coast should help to prevent any development in highly erosional coastal areas and possibly save taxpayer monies to protect buildings that should never have been built there in the first place.

Orrin Pilkey, James B. Duke emeritus professor of Earth Science at Duke University’s Nicholas School of the Environment, is co-author of the forthcoming Columbia University Press book “Retreat From a Rising Sea: Hard Choices in an Age of Climate Change.”