Background
- When we imagine the eastern-American landscape of 200-300 years ago,
most people picture a landscape of nearly continuous forests bisected by free
flowing streams.The reality was
very different.Before the fur
trade decimated beaver populations in early colonial times, beavers were
abundant on streams throughout the Mid-Atlantic region.After beavers were extirpated from the Chesapeake basin, many perennial
streams gradually became intermittent or ephemeral - possibly due to lowering
of water tables as beaver dams disappeared.Current research in the West affirms that the return of beavers can
result in a return of perennial flows to headwater areas and a more natural
stream flow regime.
The public’s (often)
negative perception of beavers precludes us from importing beavers to restore
the lost hydrologic functions.However,
researchers in the western US have developed low-cost methods to construct
shallow beaver dam-like structures (BDS) to restore riparian areas and
increase groundwater storage.By
retaining eroded material behind the structure, the BDSs reduce downstream
sedimentation and augment alluvial water storage capacity as they mature.Because they are modeled after small beaver dams, the
structures represent an ecologically guided attempt to restore what was once a
ubiquitous component of the ecosystem.
Project description - Approximately 30 shallow, in-stream structures
(click here to find out what we mean by
structures) and associated monitoring equipment will be installed in two headwater
watersheds, using a paired-watershed design.Once suitable sites are selected, we will collect preliminary data on
surface water flow and alluvial groundwater levels, install structures and,
over time, assess the effectiveness of these structures in enhancing bank and
alluvial water storage, on increasing surface flow in local streams during
base flow, and reducing sedimentation.Whether
built by beavers or people, these structures will provide beneficial impacts
for wildlife, water quality and quantity, and erosion control.While such structures may reduce and delay peak stream velocity, these
are not flood-control structures, nor are they dams in the traditional sense.We propose to partially restore the natural hydrologic functions, flow
regimes and ground water levels that likely existed prior to the colonial era
extirpation of beavers.
A Technical Advisory
Committee has been assembled to guide the process of selecting sites,
designing structures and monitoring programs, and assessing results.An Evaluation Committee consisting of the technical advisory committee
and watershed stakeholders will be assembled to decide whether to continue and
expand the process or terminate it based upon cultural acceptability
(esthetics, cost, hunting, fishing, and recreation), likely impact on water
resources in general, and potential for mitigating the impacts of groundwater
use.Back to top
Need
- Fundamentally - "EVERY WATERSHED NEEDS WATER!"Concerns over both quantity and
quality of our surface and ground water resources are widespread in the United
States.In Hardy County, WV, an
ongoing assessment of water resources finds that the poultry industry “may
impart a significant burden” on the region’s groundwater resources.Rapid development also puts pressure on groundwater resources.There is also anecdotal concern in this area that “we are sucking the
rivers dry” and recent experience indicates that new wells must be drilled
150-200 feet deeper to get the yields previously obtained from shallower
wells.
Regionally, because
sufficient flow is an important component of a healthy river system and
adequate surface and groundwater supplies are a prerequisite for sustainable
human communities and healthy wildlife habitat, this project will support the
Chesapeake Bay program’s mission to restore a system with healthy streams
and rivers and strong local and regional economies. Back
to top
Partners: U.S. Fish
and Wildlife Service, U.S.D.A. Natural Resources Conservation Service, U.S.D.A.
Forest Service, W.V. Division of Natural Resources, W.V. Conservation Agency,
Potomac Valley Conservation District, W.V.U. Extension Service,
Canaan Valley Institute
This
project has been approved for funding by the National Fish and Wildlife
Foundation’s 2003 Chesapeake Bay Small Watershed Grants Program and has been
conceptually reviewed by a number of environmental professionals.The pilot project will begin in September 2003 and run through May
2005. Back
to top
Site
selection. The stream sites selected for this project needed to meet
fairly rigid criteria.
First,
we wanted to work on first or second order streams, which are very
common.
Second,
these small streams needed to have significant deposits of alluvial
(floodplain) soils and shallow slopes. In West Virginia, this
combination is fairly uncommon, at least in the Potomac Headwaters
area.
Third,
the selected sites couldn't have active large animal agriculture, the most
common use for such lands.
Fourth,
the streams on the selected sites couldn't run directly beside a road, or
weave repeatedly back and forth across a road. Roads are often built
next to streams in these settings, further reducing the potential pool of
sites.
Finally, sites with all of the above characteristics must also have landowners
willing to allow us permission to conduct the experiments on their land.
We
feel fortunate to have found two suitable experimental sites, and one mostly
suitable control site. CI is very grateful to the three landowners for
permission to use their land.
Experimental
site 1 has two distinctly different regions - a upper forested section, and a
lower open meadow. To learn more, click here.
Experimental Site 2 is an upland meadow, and has
been enrolled in the USDA Conservation Reserve and Enhancement Program (CREP).
The control site has only a
small forested section and is mostly grassed. It was chosen for its
proximity and similar topography to Experimental Site 1, and for presumed
similar precipitation (which has, in fact, been borne out by preliminary
data). It also has "road issues." No reasonably suitable
control was found in proximity to Experimental site 2. However, we are
not
dependant on the control for our analysis, as we also have a nested
"upstream-downstream" design for each experimental site.
Current Status. The very wet fall in 2003 followed by early onset of a snowy and
cold winter has delayed important elements of our project, particularly
installation of the groundwater monitoring network. As in all field
studies, the weather rules and you have to adjust. The groundwater
measurement system was finally installed in May 2004. Flow and rainfall data has been collected
at Experimental Site 1 and the Control since late fall 2003 but, again, the very cold
winter put a halt to that for several months as well; taking flow measurements
in snow covered and frozen streams is problematic.
Data collected for this project include flow, groundwater
"level", stream height, precipitation, and water
temperature. Data analysis will be based on comparisons between
sites, in particular, between control and experimental sites, and
between upstream and downstream locations within the experimental study
areas. In order to assess change induced by installation of the structures,
the period of baseline data collection requires documenting a number of
hydrologic cycles running from wet to dry, and documenting conditions of flow
during those times. These conditions must be documented between
experimental and control sites and, particularly, between upstream and
downstream sites in the experimental streams. The wet fall in 2003 never
presented that opportunity, the winter conditions precluded it and, during
spring 2003, every time we approach a fairly low flow condition we had another period
of substantial precipitation (like April 12, 2004). Finally, in August
2004 we had the low flow conditions that we needed, and the subject streams all
became intermittent. We were then fortunate in September to have a series
of heavy rainfall events associated with hurricanes that were followed by fairly
dry periods. This allowed
us to collect important baseline data, and to proceed with constructing
structures.
We selected the cross vane as the most suitable structure for our
purpose, and have received permits from the US Army Corps of Engineers and
the WV Public Lands Corporation, and permission to proceed from the WVDNR.
Fifteen structures were installed at Experimental Site 1-Meadow during
October and November 2004. Structures will be installed at Experimental Site 1-Forest
and Experimental
Site 2 as early as weather and water levels permit in Spring 2005.
Website made
possible by funding from The Norcross Wildlife Foundation, the
National Fish and Wildlife Foundation, Virginia Environmental
Endowment, NOAA-BWET, USEPA, The MARPAT Foundation, and our generous
members.