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Pocosin Lakes Hydrology Restoration

Hydrology Restoration Map

For detailed maps of the three Hydrology Restoration Areas, visit our Hydrology Maps page.

  • Why Restore Pocosins?

    Pocosin and other peatlands are unique; they only cover about 3% of the earth’s surface.  They provide habitat for a diverse assemblage of species, including several migratory bird species in decline.  Unaltered peat soils are carbon sinks, storing more carbon than in all of the world’s forest biomass.  The past practices of ditching and draining pocosin habitat resulted in dried out peat soils that do not support healthy habitat for wildlife and are extremely vulnerable to wildfires.  Though the goals of the Refuge are wildlife related, health and safety issues are uppermost in our reasoning for all management actions.  Past wildfires on refuges in northeastern North Carolina and Southeastern Virginia have resulted in hundreds of thousands of acres burned, tens of millions of dollars spent to extinguish.  Smoke generated by peat fires have caused increases in respiratory issues resulting in emergency room visits in areas miles away from those wildfires.  Hydrology restoration reduces the frequency and intensity of fire in the pocosin.

  • What is a POCOSIN?

    Pocosin is a Native American term meaning “swamp on a hill”.  Pocosin has also been called southeastern shrub bog.  Pocosin is a shrub dominated wetland that occurs on peat.  Peat is a high organic content soil that develops under wet conditions.  Once living material decomposed very slowly in the wet/anaerobic conditions and built up in to a very slight dome (it looks flat to the naked eye) over geologic time.  Under natural conditions, the peat soil acts like a sponge, soaking up rain water and releasing it very slowly.  Hence, you get swamp on a hill (or at least on a very small dome).

  • What is hydrology restoration at Pocosin Lakes Refuge?

    The Refuge is restoring more natural hydrologic conditions in three areas that were heavily ditched and drained prior to the establishment of the Refuge in the early 1990s.  We do this by installing water control structures and low level berms at strategic locations in the ditch system to stop the artificial drainage of rain water from the soil (the Refuge lands are at the top of the peat dome, so the only source of water is rainfall).  Water levels in altered (ditched and drained) pocosins are controlled by three main factors:  1) amount of rainfall, 2) rate of evapotranspiration (evaporation and water uptake by vegetation), and drainage level.  We can’t control the amount of rain that falls or the rate of evapotranspiration; we can only influence the drainage level.  We us the water control structures to stop the drainage of water from the soil, and then allow the soil moisture to fluctuate naturally, i.e. based on rainfall and evapotranspiration.  Thus we are mimicking the natural hydrology as closely as possible given the constraints arising from the natural system being highly altered.  With normal rainfall amounts, we see lower water levels during the growing season when trees, shrubs, and other plants are using lots of water and higher water levels in the winter when the evapotranspiration rate is lower.  Water levels that exceed the drainage levels we set with the water control structures restart the artificial drainage through the ditch system just like before the restoration, but much less water is drained off of the Refuge by retaining that water in the soil.

  • Why is the Fish and Wildlife Service restoring hydrology on Pocosin Lakes Refuge?

    National Wildlife Refuges are established by Congress to provide a national network of lands and waters for the conservation, management, and where appropriate, restoration of the fish, wildlife, and plant resources and their habitats within the United States for the benefit of present and future generations of Americans.  One of the main goals for Pocosin Lakes Refuge is to conserve this unique type of wetland called pocosin.  The first step in reaching that goal is to restore the wetness where the pocosin was ditched and drained.  But equally important is the reduction in the frequency and intensity of wild fire that occurs in pocosins when the peat soil is dried out.  Because the peat is high in organic material, it will catch fire and burn when dry (we call it “ground fire”).  Artificially drying the peat out through ditching and draining greatly increases the chances of catastrophic wild fires occurring.  When burning, peat smolders and creates vast quantities of smoke that can cause human health problems.  The 1985 Allen Road Fire and 2008 Evans Road Fire are examples of the catastrophic wild fire that can occur in peatlands.  These fires burned over 100,000 and nearly 50,000 acres, respectively.  The Evans Road Fire burned much of the same area as the Allen Road Fire.  The Evans Road Fire burned for over six months and cost nearly $19,000,000 to manage.  These fires resulted in most of the above ground vegetation being burned away (i.e. complete loss of habitat for a time) and loss of as much as five feet of peat soil in places.

  • How much of the Refuge is being restored?

    The hydrology restoration work is occurring in three areas of the Refuge totaling about 35,500 acres.  This is about 32% of the Refuge’s 110,106 acres.  The rest of the Refuge was much less altered by ditching and draining with much of it being the headwaters of the Alligator River.

  • What’s some of the history regarding hydrology restoration at Pocosin Lakes Refuge?

    Established in 1991, the Pocosin Lakes NWR now totals over 110,000 acres within Hyde, Tyrrell, and Washington Counties.  The majority of the refuge consists of pocosin habitat, characterized by deep, high organic-content soils (peat) and southeastern shrub bog vegetation.  A significant portion of the Refuge was ditched prior to establishment, thus artificially drying the peat soils.  This drying increases the risk of long-duration, catastrophic wildfire (from the ignition and burning the soil itself); the most recent example is the Evans Road Fire which occurred in 2008.  To counter the effects of drainage, in the early 1990s the Service partnered with the Natural Resources Conservation Service to develop a hydrology restoration plan for the most significantly ditched and drained areas comprising about 35,500 acres, or less than a third of the Refuge.  That plan provides the basis for the restoration work we are implementing.  Advances in technology, improved knowledge of how these systems work, and better management techniques have led to some adjustments in how we do the restoration at Pocosin Lakes.  Currently we have the required rewetting infrastructure (e.g. levees and water control structures) in place on an estimated 20,000 acres, or about 18% of the Refuge.   Refuge staff members and partners have been implementing the plan for almost 25 years as funding has become available and the work is still in progress. 

     

    The majority of Pocosin Lakes NWR is managed to meet biological goals outlined in the CCP including:

    •             Wildlife Populations:  Conserve, protect, and maintain healthy and viable populations of migratory birds, wildlife, fish, and plants, including Federal and State endangered and trust species.

    •             Habitat:  Restore, protect, and enhance pocosin wetlands and other natural habitats for optimum biodiversity.  Intensively manage habitats specific to waterfowl on the Pungo Unit.

    •             Resource Protection:  Protect and perpetuate refuge resources by limiting the adverse effects of human activities and development on refuge resources

     

    Restoration of this unique wetland type is widely recognized for its multitude of benefits (beyond wildlife habitat) and is among the high priority actions in the North Carolina Coastal Habitat Protection Plan.  The wetland restoration work at Pocosin Lakes NWR has longstanding support of other natural resource managers in the state, as evidenced by its overt mention in the Albemarle-Pamlico Estuarine Study’s (APES) 1994 Comprehensive Conservation and Management Plan.  The restoration work at Pocosin Lakes NWR is also highlighted in the Tar-Pamlico River Basinwide Water Quality Plan.  The restoration follows the NC Division of Coastal Management’s Best Management Practices for the Hydrologic Restoration of Peatlands in Coastal North Carolina, which highlights the PLNWR project as an example in its “Restoration Techniques” section.  The natural resource benefits of the project prompted a 2006 partnership between the NC Department of Environmental Quality (formerly NCDENR) and the Service to restore the hydrology in the most severely drained portion of PLNWR and directly resulted in hydrologic restoration of 9,500 acres, thereby restoring the seasonally-flooded wetland conditions associated with functional pocosin ecosystems.

  • How does the restoration affect adjacent private lands?

    Only one of the three Restoration Areas (RA 1) drains completely in to canals on private land.  RA 2 drains mostly on to adjacent, lower elevation refuge lands with only a fraction of the total volume draining in to a canal that is owned jointly by the United States and an adjacent landowner.  Likewise, RA 3 drains almost completely in to adjacent, lower elevation refuge lands.  All landowners in the area, including the Refuge, have a deeded right to drain into the canal system.  Less water is released from the restored peat soils than was released prior to restoration.    Therefore the restoration provides some storm water retention benefits for downstream neighbors.  However, excess rain water must still drain (just as it always has).  The restoration areas cannot be managed to maximize storm water retention as the results would be contrary to the purpose of the Refuge.

    In recent years, adjacent landowners have expressed concern about the restoration causing or worsening downstream flooding while it actually has the opposite effect.  Unfortunately, the region experienced double digit above normal rainfall in 2014 and 2015and high rainfall amounts continued in to the first half of 2016.  All of this rainfall led to flooding in the region, but it was not caused or worsened by the Refuge’s hydrology restoration work.

    To insure seepage does not become an issue on private lands immediately adjacent to the Refuge boundary, as a general practice we do not restore the Hydrology Management Unit nearest adjacent private lands which provides a protective buffer, unless through dialog with the landowner agreement is reached that wetter conditions are suitable for all parties.  One notable exception is the planned “Clayton Blocks” 1,300-acre restoration area.  In this case, we are restoring lands in close proximity to the refuge boundary; however, we do so with confidence that it will not affect adjacent lands because 1) we are constructing a second berm interior to the existing canal and berm to hydrologically isolate the restoration area, and 2) that berm will be cored such that most, if not all, seepage would be prevented from reaching adjacent lands and any minor amount of seepage that might occur would simply drain out through the existing ditch network to the Pungo River.  We continue to work towards understanding the altered peatland system better and look for ways to help alleviate the concerns of adjacent landowners while still achieving our goal of pocosin habitat restoration.  

Last Updated: Aug 15, 2016
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