Developing a water management plan for Pocosin Lakes National Wildlife RefugeJune 29, 2017
What’s the overall management goal for Pocosin Lakes?
A key component of the refuge’s management vision is to restore and maintain natural processes and biodiversity in a functioning pocosin wetland and provide habitat for threatened and endangered fish, wildlife and plants as well as others the agency is charged with managing. Biological goals outlined in the Refuge Comprehensive Conservation Plan (CCP) include:
- Conserve and protect healthy and viable populations of migratory birds, wildlife, fish and plants, including Federal and State endangered and trust species.
- Restore, protect and enhance pocosin wetlands and other natural habitats for optimum biodiversity. Intensively manage waterfowl habitats at the Pungo Unit.
How will we achieve the management goals for pocosin wetlands?
Strategies for pocosin habitat management identified in the CCP include:
- Restore hydrology altered pocosins by installing infrastructure for water management to achieve average saturation across each hydrologic management unit (HMU), and
- Manage hydrology to mimic natural condition as closely as possible (allow for natural water level fluctuation).
Specific pocosin habitat management objectives related to the goals above include:
- Manage hydrology management units without negatively impacting refuge infrastructure, public use or adjacent landowners,
- Protect peat soils from oxidation, subsidence and loss to catastrophic wildfire, and
- Promote delivery of co-benefits compatible with refuge management goals (e.g., improved water quality, pollutant sequestration, resilience to sea level rise).
What’s the water management plan?
It outlines how the Service will manage water on the refuge. Before the refuge was established, in 1990, ditches were carved to drain water and make the ground more usable for agriculture and forestry. The Service has since worked to return the water table to a more natural state thereby restoring the wetland conditions associated with pocosins. The Service is developing a Water Management Plan to summarize existing management practices, provide linkages between management activities and refuge goals and offer recommendations for future management operations, data collection, and monitoring. The public will have input on the plan.
What is a “pocosin?”
Peatlands are one of the most unique, diminished and valuable habitats on the planet. Pocosin, a Native American word meaning “swamp on a hill,” is a Southeastern shrub bog wetlands underlain by peat soils as much as 14 feet deep. As living material died and decomposed in those wet, anaerobic conditions, it created a very slight dome that looks flat to the naked eye. The peat acts as a sponge soaking up rain and staying wet from fall to spring while sequestering pollution from the atmosphere.
The Service manages over 350,000 acres of pocosins in the Albemarle region. These lands provide important habitat for migratory birds and waterfowl, black bears and threatened and endangered species. Refuge peatlands protect water quality in the headwaters and tributaries of the Albemarle Sound, supporting healthy, productive fish nursery areas. They also provide abundant wildlife viewing, hunting and fishing for tens of thousands of visitors.
Why restore pocosins?
Pocosins are unique; they cover only 3% of the earth’s surface. Ditching and draining pocosins resulted in dried-out peat that didn’t support healthy wildlife habitat. Rewetting the Refuge’s organic, peat soils is the best way to achieve a healthy habitat, improve estuarine water quality, prevent soil loss, and reduce the duration and severity of wildfires such as the catastrophic 2008 Evans Road Fire that burned nearly 50,000 acres for more than six months.
Wildfires on refuges in northeastern North Carolina and southeastern Virginia resulted in hundreds of thousands of acres burned and cost tens of millions of dollars to control and extinguish. Smoke generated by peat fires causes respiratory problems that lead to numerous emergency room visits in communities hundreds of miles from the wildfires.
Why is the Fish and Wildlife Service restoring the hydrology?
Restoring wetness to the soil on portions of Pocosin Lakes National Wildlife Refuge where the pocosin wetlands had been heavily ditched and drained for years is Job One. The current ditch system allows rainwater to drain too quickly off the Refuge and surrounding lands into area rivers. Unnaturally dry peat soils are easily lost via oxidation. As a result, the current drainage network increases the vulnerability of peatlands to changes in precipitation, drought, wildfires, and sea level rise. Consequently, restoring pocosin hydrology saves the soil, protects life and property and meets the Refuge’s wildlife conservation purpose.
What’s the history of hydrologic restoration at Pocosin? Draining in the Albemarle region began in earnest in the early 1960s with the dewatering of peat leaving the land extremely susceptible to wildfire. And peat soils burn!
In the early 1990s, the U.S. Fish and Wildlife Service partnered with the Natural Resources Conservation Service to develop a plan to restore, or mimic as closely as possible, the natural hydrologic conditions for the most significantly ditched and drained areas of the Refuge - about 35,500 acres, or less than a third of the Refuge. Currently, the necessary infrastructure – levees and flashboard riser water control structures – are in place on roughly 20,000 acres, or 18 percent of the entire refuge. The remaining two-thirds of the Refuge were not as severely altered by the ditching and draining with much of the land comprising the headwaters of the Alligator River.
How does restoration work?
The Service tries to mimic the natural hydrologic conditions found in unaltered pocosins by building levees and water control structures strategically placed to stop the unnatural drainage of rainwater from the soil. Rainfall, evapotranspiration (evaporation and water use by vegetation) and ditches control water levels in the peat soil.
Without the artificial drainage from ditches, water levels in a pocosin typically drop during the growing season due to thirsty trees and shrubs. They usually rise during the winter when evapotranspiration is lower. Ditches can also direct flow to some degree, but not during big storms that overwhelm the ditch system. When this happens, water rises out of the ditches and off of the peat dome like it did before the ditch system was built.
The new infrastructure enables the Refuge to rewet historically drained peatlands and return lands to a natural, seasonally-saturated condition.
How does the restoration impact neighbors?
Only one of the three Restoration Areas (RA-1) drains completely into canals on private land.
RA-2 drains mostly onto adjacent, lower elevation refuge lands with minimal draining into a canal that is owned jointly by the Service and a private landowner. RA-3 drains completely into adjacent, lower elevation refuge lands. Yet some of this water travels via another canal owned jointly by the Service and another private landowner. All local landowners, including the refuge, have a deeded right to drain into the common canal system.
Monitoring and modeling information from North Carolina universities and federal agencies indicates that activities to re-wet drained peatlands do not result in downstream flooding. Recent flooding of the Refuge and adjacent lands resulted from unusual and excessive amounts of rain falling on an already saturated ground. Restoration areas can’t be managed to maximize storm-water retention; that’s contrary to the Refuge’s purpose and goals.
How do big storms impact the refuge and neighbors?
The area in and around Pocosin Lakes averages 45.6 inches of rain per year, according to the National Oceanic and Atmospheric Organization. In 2016, it received 82.3 inches. In recent years, more severe weather events with great deluges of rain have occurred. Some refuge neighbors blame the restoration for downstream flooding. But restored pocosins allow the refuge to retain more water – not less – during these extreme periods of weather.
Is the Service trying to better control water going off the refuge?
Yes. The Service is taking steps to avoid short-term impacts to adjacent lands by installing berms, water control structures and canals within refuge boundaries. Typically, we also avoid restoration of pocosins in refuge areas near adjacent landowners to keep water from seeping onto private property.
Service staff has openly engaged neighboring landowners and others through one-on-one interactions, group meetings and site visits. Employees have identified opportunities of mutual interest with great potential to improve drainage conditions: weir modifications on Refuge to attenuate the timing and rate of water releases; and maintenance and capacity improvements on an outlet canal.
Input is needed at open houses in late July to help us ensure that issues and concerns of all interested parties are addressed in the water management plan. They’ll be held in Hyde and Tyrrell counties. The schedule and location is available on the refuge website at https://www.fws.gov/refuge/pocosin_lakes/.
Public comments, along with research by government and independent scientists, will be included in the draft water management plan.