The torrential week-long rains of late
September and early October, coupled with overwash generated by an
offshore tropical system, resulted in unprecedented levels of
flooding in the Cape Point area. Portions of Lighthouse Road, Cape
Point Campground, and Ramp 43 and Ramp 44 were closed for weeks.
Standing water covered the road surface and inundated the campground
for several months.
Beyond the dune line, the Dredge Pond
basin, also known as the "Salt Pond," filled to cover the
interior of Cape Point. Hatteras Island residents and visitors alike
are becoming all too familiar with flooding in this area. Once a
rare and short-lived occurrence, flooding of this area seems to be
becoming more common and acute. The inundation of 2015 may have been
the worst to date.
Climate change and sea level rise may
well be contributing to the frequency and severity of flooding along the
interior of the Cape Point and elsewhere on the island. These twin
forces will surely challenge our island in the coming decades and
beyond. However, the immediate problem at Cape Point is entirely
local in origin.
HOW WE GOT HERE
The root cause of the flooding lies in
the construction of the protective dune system by the Civilian
Conservation Corps (CCC) during the 1930s. Erection of the dune line
severed the natural hydrological connection between the interior of
Cape Point and the ocean. The result is a large artificial basin that
collects stormwater that has nowhere else to go.
To mitigate this, the National Park
Service connected a ditched stream that circumvents the campground to
a steel culvert that runs under the dune line just west of Ramp 45.
Presumably, this work was undertaken in association with the
development of the campground and other park facilities. The enhanced
steam channel connects with the roadside ditches near the campground
Two control structures were installed
and maintained to regulate water passing through the channelized
system. One is located on a dirt track that crosses the stream just
west of the campground and the second near the entrance to the steel
culvert extends under the dune line. A third opportunity to evacuate
excess water was purportedly located along the north beach
approximately half way between the Ramp 43 and the current lighthouse
location. Here a straight line ditch runs from Lighthouse Road
northeast to terminate along the dune line.
The recurring flooding of the last
decade or so is the direct result of stormwater purposefully being
blocked from entering the steel culvert west of Ramp 45. This
blockage appears to have been started around 2004 in response to a
Notice of Violation (NOV) issued to the Park Service by what was then
known as the North Carolina Division of Water Quality. The NOV, dated
Sept 16, 2004, specifically cites concern that the above described
drainage system may be lowering water levels in the wetlands that
characterize areas along Lighthouse Road.
The NOV was recently located by NPS
staff and widely distributed by the seashore's new Superintendent
David Hallac, who arrived last January and witnessed his first
flooding event in the Cape Point area in early October.
When I read a copy of the NOV,
it was clear to me that the State of North Carolina never intended
for the hydrological connection to the ocean to be fully severed.
Rather, the NOV specifically directed the NPS to produce “a
restoration plan [which] should include a draft management plan that
addresses maintaining the appropriate water levels in the wetland by
modifying the drainage culvert.”
The NOV further directed that “the
plan should include a water level monitoring plan utilizing the
existing staff gauge located at the upstream opening of the culvert.”
The NPS officially responded in a
letter dated October 25, 2004.
This letter, signed by then superintendent Lawrence Belli, was also
located and widely distributed by the current superintendent Hallac.
The response letter addresses concerns
raised in the NOV and presents an action plan to bring the park into
compliance. Called for in the action plan was the immediate
construction of two modified water control structures that would more
effectively regulate water flow. This was to be followed by the
development of a Wetlands Management Plan. It would appear that
neither of these actions was ever carried out.
None of the proposed modified water
control structures are known to have been built, nor does any
Wetlands Management Plan appear to have been developed. Rather than
complying with terms of the NOV issued by the State of North
Carolina, the NPS appears to have simply closed the sluice gate that
allows water to enter the culvert and flow under the dune or
otherwise blocked the drainage. This action has directly resulted
in ever worsening stormwater accumulations within the interior portions
of the Cape Point area.
In mid-December, Ramp 44 was still
closed by standing water.
What is perhaps the most unfortunate
aspect of this situation, over and beyond the loss of recreational
opportunities provided by the campground and the beach access points,
is the environmental and ecological detriment wrought by the standing
water. The human-induced stormwater pooling behind the dunes has
likely significantly degraded the quality and function of the
wetlands in question.
What is ironic is that it remains
unclear to what extent, or even if wetlands were ever being
compromised in terms of water level draw down. It is possible and
perhaps likely that the water conveyance and control infrastructure
originally constructed by the NPS fairly closely mimicked the area’s
natural hydrology, specifically its connection to the ocean that
would be sustaining itself had the dune system not been constructed.
In short, the wetlands that the state
of North Carolina sought to protect have been significantly degraded
by severing their natural hydrological connectivity. This is
expressed in the diminishment of critical wetland service functions
to include: water quality, plant diversity, wildlife habitat, and
aesthetic and cultural value.
Prior to drainage being blocked, this
area along Lighthouse Road was --- at the very least -- a mix of
quality, high functioning forested wetlands and scrub shrub wetlands.
Not only is the aesthetic and cultural value of the natural resource
being compromised, the dramatic die back in mature trees, scrub and
other vegetation is clearly a major loss of wildlife habitat, and a
detriment to plant diversity.
Plant diversity is also being
compromised by the ongoing rapid spread of cattails which thrive
where static water levels dominate. A larger threat to the diversity
of the existing wetland plant communities is the invasive
phragmites reed, which is making its presence known. Impact on
the water quality function of wetlands is perhaps most troubling,
particularly by way of soil filtration and nutrient uptake. What was
once an optimal mix of small, fluctuating open water bodies and large
areas of perennially and seasonally saturated soils is fast
transitioning to a stagnant, cattail and reed-choked stormwater
A PROPOSED WAY FORWARD
What is clearly needed is a way forward
to rectify this unfortunate situation. A useful approach would be to
split two separate but closely related needs.
These are how to:
1) Responsibly evacuate ocean overwash
and extreme precipitation trapped behind the dune line as a result of
hurricanes and other severe events.
2) Properly manage the normal water
levels in the wetlands by controlling outflow through the trans-dune
line culvert, as directed by the North Carolina regulatory
authorities in their 2004 NOV issuance.
An apparent popular misconception is
that the NPS is not able to evacuate water from behind the dune as it
is polluted and/or contaminated by septic run-off. This is not
substantiated. The misconception is apparently based on some limited
recreational swimming and shellfish harvesting water quality
monitoring efforts carried out by the Marine Fisheries Division of
the North Carolina Department of Environmental Quality (DEQ).
This is the state agency under which
the Division of Water Quality is now organized as the Water Resources
Division. In the early 2000s, North Carolina DEQ identified elevated
levels of enterococcus
bacteria in beach water near the culvert outflow. The
bacterium is found in the intestinal tract of warm-blooded animals.
It is harmless to humans but its presence is used in water monitoring
as a marker for potentially harmful organisms.
NPS sponsored more detailed water quality studies reported in
"Assessment of Coastal Watershed Conditions at Cape Hatteras
National Seashore, North Carolina," published May
2006. Mean fecal
coli form levels in surface water swales in the Buxton area were
analyzed in the study. For Buxton surface water, the
concluded that “septic leachate contamination was minimal to
non-existent and the periodic elevated fecal coliform bacteria counts
were likely due to wild animals congregating at the swale sites”
a limited numbers of beach water samples containing enterococcus
were registered in the North Carolina DEQ monitoring study cited in the
above NPS sponsored technical report. These were recorded during spring
and summer of 2003 near where the culvert was discharging. The presence
of potentially harmful bacterium was not established. Wildlife is a
likely source of the enterococcus in the drainage water as well, not
just in the interior swale wetlands but also from gulls, and other
flocking shorebirds that gather around standing fresh and brackish
water where it pools near the surf zone.
The following proposal is made to
mitigate the ongoing flooding issues at Cape Point as well as the
resulting environmental damage and loss of recreational
The NPS should immediately develop a
water and wetlands management plan for the Cape Point area. This plan
should be comprehensive in nature and address not only catastrophic
stormwater evacuation and wetland protection along Lighthouse Road
but also in the area of the Dredge Pond. Although this man-made
feature lies outside the dune line, it nonetheless is integral to
Cape Point’s hydrological regime and environmental condition.
evacuate catastrophic storm water, it is proposed that a simple box
weir be constructed at the head of the existing ditch east of
Lighthouse Road where it meets the dune line. A box weir is typically a
four-sided concrete structure open and grated on the top to let water
flow in. Such a structure would connect to a concrete pipe that extends
under the dune line and onto the North Beach. This pipe could be buried
under the sand with the opening marked with deeply set posts.
Following catastrophic events, the end
of the pipe would simply be "daylighted" with a
backhoe/loader and a drain channel initiated to the tide line. Once
the excess water is evacuated, the pipe opening would be covered with
treated wood and the sand pushed back by the loader to restore the
beach contour. In this manner, the pipe would remain fully out of
view and protected from storm tides. The great advantage of a box
weir as a water control device is that it is self- regulating and
only lowers water to a single pre-set level equal to the top of the
Once catastrophic stormwaters are
evacuated, appropriate water levels in the wetlands can be maintained
by the two water control structures originally proposed by the NPS in
response to the violation notice. This original proposal called for
simple concrete structures that allowed treated wood slats to be
inserted or removed for a determined flow level to the culvert near
Ramp 45. This is in contrast to the existing drop gate installation.
Opening of the culvert near Ramp 45
would be accompanied by water quality monitoring. Should unacceptable
bacteria counts be present, then a time-of-year restriction could be
implemented that limits discharge to outside the recreational
swimming season. However, any time-of-year restriction would likely
not be warranted. Under normal summer conditions, sun induced
evaporation and evapotranspiration by vegetation would likely remove
sufficient water volumes to preclude any need for discharge under the
dune. In years past, flooding has occurred almost entirely in the
fall months as the sun angle recedes and the growing season wanes.
Finally, the management plan should
address conditions around the Dredge Pond. The NPS should reinstitute
a program of actively managing both vegetation and water levels in
and around the artificial lake. When the dredge pond was first
excavated, the surrounding terrain was characterized by extensive
open areas and flats that mimicked natural salt flats and overwash
fans. These areas were maintained by periodic draw down of the pond.
These conditions provided highly favorable breeding and foraging
habitat for the endangered piping plover.
In recent years, the Dredge Pond has
expanded in size and vegetation has overtaken much of the remaining
fringe area. Since its creation as a borrow pit for beach
nourishment sand, storm tides have brought in silts and other fine
sediments that have settled to the bottom of the pit and surrounding
flats, causing water to perch and stagnate. The NPS should resume
controlled draw down of the Dredge Pond during the winter months.
This would expose the former flats areas to be used as piping plover
breeding/foraging habitat in the spring and summer.
This, together with vegetation control
clearly has the potential to assist piping plover recovery efforts by
providing alternative nesting areas to the surf zone, where nests are
dangerously exposed to storm tides and ghost crab predation.
These proposed actions are fully consistent with management activities
undertaken in other areas of the seashore, most notably the part
occupied by Pea Island Wildlife Refuge. It is perhaps ironic that the
portion of the seashore set aside for wildlife is highly managed
through activities to include habitat enhancement, extensive water
control structures, water draw down, proscribed burning, and invasive
By contrast, much of the seashore that was established in significant
measure as a recreational asset has seen relatively little active
management in the last decade or so, at least in terms of protecting
wetlands and enhancing breeding and foraging habitat for an endangered
The NPS and certain activist stakeholder groups need to acknowledge
that the seashore, and the Cape Point area in particular, is not a
pristine wilderness. Rather, these areas have been heavily
altered by human hand, mostly under auspices of the federal government.
Given the man-made alteration to the interior Cape Point area, a
continued abdication of active management responsibilities by the NPS
can only lead to more environmental degradation and loss of
The NPS is therefore called upon to
immediately move to comply with terms of the NOV issued by the state
of North Carolina over a decade ago and properly manage the wetlands
along the Cape Point interior. The NPS is also called upon to resume
active management of the Dredge Pond area through appropriate draw
down and vegetation control measures.
Reasonable and prudent management of
the Cape Point area on either side of the dune line will serve to
both enhance the quality of the environment and ensure continued
public access and appropriate recreational opportunities.
David Hallac, the seashore's
superintendent, has said publically in interviews that he is pursuing
solutions to the stormwater and flooding problems in the Cape Point
The state, Hallac says he was told,
does not "permit" federal agencies to drain wetlands but
would like to work with the Park Service on a plan for managing
stormwater issues in the sensitive maritime area.
Hallac has also been in touch with the
U.S. Army Corps of Engineers, which, he says, may have to permit any
plans to park comes up with.
This winter, he said, seashore staff
will continue to pursue the issue with the state Department of
Environmental Quality and the Army Corps of Engineers.
There is no doubt that manmade
structures -- from the dunes that were constructed in the 1930s to
the Cape Point campground -- have changed the hydrology of the area.
But correcting the problem is much more complicated than it might
seem by such issues as state and federal laws and Park Service
"I'm not promising anything,"
Hallac said, "because my guess is that this will become more
complicated before it becomes clearer. But we're going to do our best
to make improvements."
Note: Chris Egghart is an environmental professional with 15 years
experience in the Middle Atlantic and Southeast regions of the U.S. He
has extensive experience producing natural resource management plans
for federal agencies and is currently active in wetland restoration
projects and compensatory mitigation programs for stream and wetlands