The recent controversy regarding the Walther Potato Farm’s proposed withdrawal from the South Fork of the Edisto River is a blatant example of state government’s disregard of its fiduciary responsibility to protect public trust resources.

This responsibility is clearly defined by the common law Public Trust Doctrine (PTD), whose origins can be traced back to the Justinian Code of Roman history. It became part of European law in the Middle Ages and transferred to American law with the states becoming trustees.

Among other things, the PTD calls on state government to protect the rights of its citizens to access and enjoy water resources of the state. Principles of public trusteeship include the following:

Certain interests have such importance to the citizenry as a whole that it would be unwise to make them the subject to private ownership.

These interests are so intrinsic with the bounty of nature, rather than individual enterprise, they should be made freely available to the entire citizenry without regard to economic status.

A principle purpose of government is to promote the interests of the general public rather than redistribute public goods from broad public uses to restricted private benefit.

The 2010 Surface Water Bill was a step forward for South Carolina. Previously there was no direct way to restrict how much water anyone could take from a river, creek, lake or estuary. The bill allowed for permitted withdrawals based on safe yields calculated as a proportion of the average annual flow of a river. For the first time, South Carolina recognized that water needs to be left in streams for natural stream functions, habitat, and recreational purposes. However, a major flaw of the bill is exemption of agricultural users who only need to register (not permit) their withdrawals.

The South Fork of the Edisto River is a small stream within a very sensitive basin. The Edisto River is the longest undammed blackwater river in the U.S. and also one with an extensive amount of conservation lands, including Beidler Forest and ACE Basin. The average annual flow in the South Fork at the point of withdrawal is only 372 cubic feet per second (cfs). During low flow times of the year (summer–fall) a normal flow may only be 74 cfs. The Walther registered withdrawal is 41 cfs per day — more than half of the low-flow season and more than two-thirds of the lowest recorded flow (57 cfs). It is important to recognize that during low-flow periods, any permitted withdrawer would have to cease pulling water from the stream if the seasonal safe yield is exceeded. Not so for agriculture, which can continue withdrawing water until the stream goes dry.

Compounding negative effects is the fact that stream biology responds to instantaneous flows, not necessarily average flows (the basis for safe yield calculations). This belies the statement by DHEC that the Walther operation would take only a fraction of the South Fork’s water since the mean annual daily flow of the river is about 241 million gallons per day (449 cfs), but Walther’s withdrawals would take less than 27 million gallons each day (27 cfs).

What was not addressed in the DHEC statement is that there is nothing to preclude continued withdrawals during low flow periods significantly lower than the average annual flow. For example, if the historic low flow (57 cfs) were present, their 41 cfs withdrawal would take streamflow down to 16 cfs. That’s 72 percent of the flow at a most critical time.

Streamflow alteration affects not only recreational use but also stream health. Streams evolve over time under a flow regime to maintain a dynamically stable channel. It is under these conditions that the stream provides maximum diversity of habitats, is in balance with its floodplain, and fully supports its myriad of organisms and ecosystem services. The potential loss of recreational and ecological values in the Edisto is of great concern.

However, of even greater concern is that the current exemption for agricultural withdrawals would allow such scenarios to play out in rivers and streams throughout the state. Streamflow-derived impacts would have amplified severity in light of predicted weather patterns with increased drought periods.

In pandering to agricultural lobbies, the state has abandoned its responsibility to protect trust resources for all its citizenry and is ripe for a lawsuit under the Public Trust Doctrine. It has also ensured that other potential water users (e.g. other industry, municipalities, utilities) may not be able to get needed withdrawal permits in light of unpermitted excessive agricultural withdrawals.

The Surface Water Bill needs an immediate fix. In addition to reinstating a permitting requirement for agricultural withdrawals, consideration should also be given for requirement of a site-specific instream flow study for any large withdrawals in particularly sensitive streamflow limited watersheds. This would help inform the permitting decision by evaluating stream impacts on an instantaneous vs. average flow basis.

Steve Gilbert is retired from a career with the U.S. Fish and Wildlife Service and the National Oceanic and Atmospheric Administration, where he worked on wetland, stream, river and coastal issues. A resident of James Island, he serves on the Audubon South Carolina Advisory Board.