What is in this article?:
- Saltwater intrusion threatens eastern North Carolina crops
- Big changes over the years
- Strong water holding capacity
• Using a simple, but high tech dam and pumping system, growers can manipulate fresh and saltwater levels in the canals.
• The pumping stations and the canals are closely regulated and getting permits quickly enough to avoid saltwater contamination is an ongoing challenge for many growers in the area.
NORTH CAROLINA Farmer Ray Tooley explains some of the challenges of farming on land surrounded by saltwater.
Big changes over the years
“I can show you modern day satellite photographs that clearly show the outline of roads and remains of farm houses that are now part of the estuary,” Gibbs says. “There is plenty of historical evidence of thriving farm communities back in the late 1800s and early 1900s that simply don’t exist anymore, due to tidal changes and saltwater intrusion,” he adds.
Now, a canal system is used to pump saltwater out of land re-claimed for farming.
Using a simple, but high tech dam and pumping system, growers can manipulate fresh and saltwater levels in the canals. The pumping stations and the canals are closely regulated and getting permits quickly enough to avoid saltwater contamination is an ongoing challenge for many growers in the area.
“The first thing you have to consider before you plant a crop here is: How can we get rid of any excess water,” Tooley says.
“The rich clay soils on the peninsula go down about five feet, then become sand. Waiting for salt, or in more precise terminology, sodium to filter through the clay and then rapidly filter through the lighter sandy under-soils can be a costly and time consuming process,” he adds.
Cleaning up land from salt water intrusion can take a few years, or in some severe cases up to 15-20 years. Most farmers simply don’t have the resources to speed up the process, nor the time to wait for Mother Nature to clean up the soil from salt contamination.
Adding fresh water is an option, but never an easy one and sometimes virtually impossible. There is no freshwater source near enough to use for irrigation, which would be the simplest approach to reclaiming farmland from saltwater intrusion by flushing out the sodium.
“Most of the water from our nearest freshwater source has 1,200 or so parts per million salt and that’s too high to sustain plant life. Even much lower volumes of contamination would be enough to significantly reduce crop yields,” Tooley says.
One approach the North Carolina farmer uses is a system he calls parallel ditching.
About 12 years ago, North Carolina made available some funding from the National Resource Conservation Service to be used to build flood gates on some of the Hyde County farmland.
Using grant money and some of his own, Tooley and other farmers in the black lands have been able to keep saltwater at bay on much of their land.
Despite their successes, Tooley says the problem of saltwater intrusion is clearly going to continue to be a problem in the region. And, much to his dismay, the problem seems to be getting worse in the past few years.
Since 1996, eastern North Carolina has been hit by seven major hurricanes, the last being Hurricane Irene in 2011.
Speaking to representatives from the North Carolina Division of Coastal Management and the North Carolina Coastal Resources Commission — the agency responsible for regulating development in coastal North Carolina, along with state and county leaders in mid-November, Tooley said the equipment shop in which the group was standing, was 3-4 inches underwater during Irene.