United States
Environmental Protection
Agency
Office of Water
(4504F)
EPA842-F-98-003L
April 1998
•''^S-lfA'iS^ffSSg1:!:^™"''^
oclc Barbs Enhance Fish Habitat and Water
Demonstrating Practical Tools for Watershed Management
Through the National Estuary Program
| Characteristics:
1 „ „ ._,;
• The watershed for Oregon's Tillamook Bay extends over
570 square miles and is drained by five rivers.
• The watershed supports several resource-based economic
activities, including logging, fishing, shellfishing, and dairy
and crop agriculture, which are vital to the region's
economy.
_ The Project:
• The Biotechnical Barb Structure and Gravel Bar
Stabilization Project was designed to be a low-cost, easily
implemented, fish-friendly method of stream restoration
which lessens erosion and sedimentation while improving
fish habitat.
Tillamook Bay Watershed
The Problem:
• The intensive nature of resource-dependent economic
activities over the past 150 years has altered the system's
natural processes and contributed to an array of
environmental problems in the Tillamook Bay estuary and
watershed.
• Priority concerns of local residents include bacterial
contamination, erosion within the watershed and resultant
sedimentation within the bay, and degradation of habitat for
salmonid spawning and rearing.
• Both sedimentation and loss of salmonid habitat can be
traced, in part, to excessive stream bank erosion, lack of
stream type diversity, and limited riparian vegetation.
Estuaries and other coastal and marine waters are national
resources that are increasingly threatened by pollution, habitat
loss, coastal development, and resource conflicts. Congress
established the National Estuary Program (NEP) in 1987 to provide a
greaterfocus for coastal protection and to demonstrate practical,
innovative approaches for protecting estuaries and their living
resources, ........... . . .
As part of the demonstration role, the NEP offers funding for
member estuaries to design and implement Action Plan
Demonstration Projects that demonstrate innovative approaches to
address priority problem areas, show improvements that can be
achieved on a small scale, and help determine the time and resources.
needed to apply similar approaches basin-wide.
The NEP is managed by the U.S. Environmental Protection Agency
(EPA). It currently includes 28 estuaries: Albemarle-Pamlico
Sounds, NC; Baratariq-Terrebonne Estuarine_ Complex, LA;
Bamegat Bay, NJ; Buzzards Bay, MA; Casco Bay, ME; Charlotte
Harbor, FL; Columbia Rivet; OR and WA; Corpus ChristiBay, TX;
Delaware Estuary, DE, NJ, and PA; Delaware Inland Bays, DE;
Galveston Bay, TX; Indian River Lagoon, FL; Long Island Sound,
CT arid NY; Maryland Coastal Bays, MD; Massachusetts Bays, MA;
Mobile Bay, AL; Morro Bay, CA; Narragansett Bay, RI; New
Hampshire Estuaries, NH; New York-New Jersey Harbor, NY and
NJ; Peconic Bay, NY; Puget Sound, WA; San Francisco Bay-Delta
Estuary, CA;.San Juan Bay, PR; Santa Monica Bay, CA; Saraspta
Bay, FL; Tampa Bay, FL; and Tillamook Bay, OR.
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Representative of the estuaries nestled between the
Northwest Coast Range and Pacific Ocean, Tillamook
Bay and its surrounding watershed provide critical habitat
for countless plant and animal species. Since the area's
settlement in the 1850s, these resources have supported
the growth of the region; many of the industries which
developed over a century ago still exist today.
Forestland accounts for roughly 50% of the upper
watershed. Virtually all of the private forestlands have
been harvested at least once this century, while public
lands, having suffered a series of fires, will again be
ready for harvest in the near future. In the lower
watershed, 20,000 cattle produce much of the milk for the
State's largest creamery.
The 13-square mile estuary produces a rich harvest of
shellfish. Although commercial salmon fishing in the bay
was closed in 1962, sport fishing remains important to the
local economy. Over the past quarter century, however,
Tillamook Bay has witnessed dramatically reduced fish
runs and repeated closures to shellfishing.
Only 80 miles from the Metro-Portland area, the
watershed is a very popular tourist destination and second
home and retirement site-for the region's 1.5 million
residents.
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As the environmental impacts of the watershed's
resource-based economy became more evident, concerned
citizens petitioned the US EPA to establish the Tillamook
Bay National Estuary Project as a means to address the
bay's declining health and productivity—particularly
pathogenic contamination, erosion in the watershed and
sedimentation in the bay, and salmonid habitat
degradation.
To help address the latter two issues, the Estuary Project
supports the Biotechnical Barb Structure and Gravel Bar
Stabilization Project. Now completing its second year,
this effort is showing significant returns from a relatively
minor investment.
By strategically pointing rock structures known as barbs
into the stream channel and following up with tree
planting, this effort fosters channel structure diversity and
increased riparian vegetation. The stabilization project
provides a low-cost, fish-friendly means of addressing
sediment loading and degraded salmonid habitat.
•»*««*-•«"•••«••*<
plantings area
Through strategic in-stream placement of rock barbs,
followed by riparian plantings, the Project aims to improve
salmonid habitat by achieving the following objectives:
• stabilizing stream banks,
• improving stream channel structural diversity, and
• improving or establishing riparian vegetation.
The concept is simple; rocks are placed in the stream to alter
flow and create new habitats. Specifically, a barb is
constructed pointing into the stream, diverting the stream's
thalvveg (area of highest velocity flow) away from eroded
streambanks, and creating slack water on the barb side of the
stream. Sediment collects behind the barb while scouring
occurs off its point. As sediment continues to fall out in the
slack water, a bar forms which is then stabilized by willow
plantings.
The engineering of the barb depends on the nature of the
river segment. The velocity of the stream determines the
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size of the rock used, while channel morphology
determines the angle of the barb. Once the composition
and shape of the barb are established, the rocks are built
into the channel bed and stream bank to avoid
destabilization and a layer of riprap is placed on the bank
upstream and downstream from the barb.
After the barb and riprap are in place, the streambank is
graded and vegetated. The upper bank is planted with
willow posts and the top with conifers. When enough
sediment has collected behind the barb, the newly-formed
bar and lower bank are planted with willow posts or other
flood-tolerant species. Willow posts range in size from two
to four niches hi diameter and four to five feet in length.
Success Stories:
Stream restoration practices
are often criticized for
incurring high costs, while
producing negligible
returns. Planting trees to
stabilize banks without first
altering stream flow is
generally not successful in
areas of high velocity
flows. Stream bank
stabilization using riprap is
costly and does not add to
the diversity of the stream.
The barb project succeeded
in meeting both of these
concerns. The cost of the
barbs varied, depending on
a number of factors, but
generally ran between
$2,000 - $3,000 per
structure.
«
The Tillamook County Soil
and Water Conservation
District began the Barb
Project in the spring of
1996 by constructing seven barbs in the Kilchis River.
After the first two years, which included several
significant winter flood events, the barbs produced
noticeable benefits. In addition to reducing sediment
loads from eroded banks, the barbs protected vegetation
introduced on the bar and in the riparian zone. As the
vegetation becomes more established, it will contribute to
a more natural stream channel and further dissipate the
energy of the system. This system uses the natural flows
and recruitment of the stream to establish the channel.
The barbs trapped sediments, which increased the size
and elevation of the bar and created a deeper, narrower
stream channel at low flows than had previously existed.
The increase in depth and reduction in water surface area
at low flows resulted in maintained stream temperatures.
For summer- and fall-run (as well as local) fish, these
deep, lower-temperature areas offer refuge. At higher
flows, when the bar was flooded or overtopped, the
plantings served as refuge for fry.
Finally, the barbs returned stream morphology and
channel diversity to a more natural state. Increased
meander and newly-created scour areas increased
salmonid habitat while reviving some of the Kilchis'
natural sinuosity. Spring and Fall Chinook now take
refuge in the deep scour pools off the tip of the barb as
well as the eddies which form
behind it. The barbs trapped a
great deal of organic material,
which is good for river channel
complexity and, when plantings
take hold, the area will receive
increased organic matter. This
increase will, in turn, create more
habitat. In addition to the
increased supply of coarse woody
debris, riparian vegetation will
also provide canopy cover which
will maintain low stream
temperatures.
In sum, the barbs have begun to
achieve their stated goals of
stabilizing stream banks,
improving stream channel
structure, and adding salmonid
habitat. Riparian plantings
withstood high water levels due
to the barb's flow diversion and
are expected to flourish in newly-
stabilized banks. Adult Chinook
salmon were seen using the
newly-created scour pools for
refuge while smolts used the
slack water behind the barb for
cover. Over tune, the barbs and
vegetative plantings will continue
to produce the following benefits:
• re-establishment of meander geometry and scour pools,
• diversion of flows from high erosion areas resulting in
reduced sediment loading,
• reduced water surface area at low flows resulting in
maintained water temperatures and deeper pools,
• increased stream structural diversity through
reintroduction of gravel bars and loadings of coarse
woody debris,
• increased aquatic refugia at high and low flows,
• increased stream shading/cover, and
• increased natural nutrient input.
pre-planting bar shape
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Of the twelve barbs constructed as part of the
demonstration project, all but one held entirely in place.
The one failure yielded an important lesson. Depending on
the condition of the bank, the flow rate, and angle of the
current, it is critical to use lar^e enough rocks and "key"
the bjj|£i*fr enough into the tggje: Experience helps in
recogntrihg the size arid amount of rock needed in any
gfeeR localSon and" there' Is no formula for what is . --'-\
appittjirlate. As a rule of thumb however, at least -1 Q% 'b,f' - -:
llS.bjirli's |2|a| J£I»gih should Se tmild'k info the bank'. i ' ''' _
=Art0^5f'Useful rule' is, wKen placing npn^'upsTreanT, bring ,
itjg',2''point even with" tfie upjpeFierid'of'the barb. This will "
;"tSniUre that tlie bank doesn't erode and displace the riprap
, , : , , ',
Bill1
Report Title
National Estuary Program bate Publication #
Biological Nutrients Removal Project
Buttermilk Bay Coliform Control Project
Georgetown Stormwater Management Project
Texas Coastal Preserves Project
Shell Creek Stormwater Diversion Project
City Island Habitat Restoration Project
Buzzards Bay "Sep Track" Initiative
New Options for Dredging in Barataria-Terrebonne
Coquina Bay Walk at Leffis Key
"Pilot Project Goes Airborne"
The National Estuary Program: A Ten-Year Perspective
Long Island Sound, CT/NY 1995 EPA842-F-95-0001A
Buzzards Bay, MA 1995 EPA842-F-95-0001B
Delaware Inland Bays, DE 1995 EPA842-F-95-0001C
Galveston Bays, TX 1995 EPA842-F-95-0001D
Puget Sound, WA 1995 EPA842-F-95-0001E
Sarasota Bay, FL 1995 EPA842-F-95-0001F
Buzzards Bay, MA 1997 EPA842-F-97-0002G
Barataria-Terrebonne Basin, LA 1997 EPA842-F-97-0002H
Sarasota Bay, FL 1997 EPA842-F-97-0002I
Narragansett Bay, RI 1997 EPA842-F-97-0002J
General NEP Discussion 1998 EPA842-F-98-0003K
SFor Copies_of any of these publications contact: :
National Clearinghouse for Environmental Publications
Telephone: (513)489-8190
Facsimile: (513)489-8695
United States
Environmental Protection Agency
(4504F)
Washington, DC 20460
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