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Comanche Creek Native Trout Habitat Restoration Project Appendix A 1
Appendix A
Toolbox for watershed restoration
Listed below are methods that have been developed for stabilization of watershed areas impacted by past
land uses. These methods have application in wetlands, dry uplands and in stream channels. One or more
of each of these methods may be used in treatment areas in the Comanche Creek watershed. Treatment
descriptions and diagrams are provided.
Grade Control Structures
Grade Control structures are used to prevent down-cutting of a channel or to raise the grade of a channel
or swale. These structures are grouped together as “grade controls”, and include the Rock Check Dam,
One Rock Dam, Filter Weir, Media Luna, Rock Plug, Sheet Piling dam, and Straw Bale Filter Dam. The
different names of the structures reflect the details of construction and the unique positioning and purpose
of each structure. In general, raising the grade of a channel raises the water table, wets a larger area and
encourages the growth of wetland vegetation. More vigorous vegetation, in turn, stabilizes the grade
control structure, and over time, the structure disappears beneath the expanding wetland.
With the exception of the Sheet Piling Dam, Check Dam and Straw Bales, each of the above structures
are constructed from various sizes of rocks placed one rock high, with the height of the structure limited
by the size of the largest rock. Placing the rocks only one rock high greatly reduces the chance of the
rocks rolling off the structure, and makes for a more stable grade control. Each structure is built so that
the lowest row of rocks acts as a splash pad and prevents scour erosion at the base of the structure. These
structures are built using hand tools such as shovels, picks, digging bars and utilize either wheel barrows
or pickup trucks to transport rock to work sites
Rock Check Dams may be either small to moderate in size (constructed with hand tools and/or with a
backhoe or small bulldozer) or may be built with a D6 bulldozer to include the full channel width (in
ephemeral drainages only) and include the first terrace floodplain bench. Typically only the smaller sized
check dam will be used for most restoration sites and could be constructed with native rock or soils. The
smaller dams are usually less than 2-ft in height and designed to be porous to allow for slow water
percolation through the structure. The larger dams would be designed to significantly slow water
movement, thereby increasing sediment capture and wetland vegetation recovery. The larger dams are not
designed for long-term water storage but are expected to fill in with sediment over time and be overtaken
by wetland vegetation recovery.
A Filter Weir (One Rock Check Dam/Boulder Weir) is designed to raise the bed of a gully by trapping
sediment. It is used when the channel bed is primarily gravel or cobble. These are built in three sections
from several parallel rows of boulders placed in a channel bed at right angles to the direction of water
flow.
A Media Luna is used to disperse water flow from sheet erosion. “Sheet flow spreaders” have the tips up
to disperse channelized flow while the “Sheet flow collectors” are constructed tips down to create a
transition between sheets flow and channelized flow at the heads of rills and gullies.
Straw Bale Filter Dams are used to re-establish wetlands by promoting wetland vegetation establishment
in areas that had been impacted by wetland soil loss. The straw dams are installed in the wetland channel
to help slow water flow, capture sediment, increase organic content and create a stable growth medium
for wetland grasses. When available, wetland coir logs and Carex sp. sod mats will be used in conjunction
with straw bales. Straw bales will often be used in conjunction with soil amendments to increase the
capacity of the treatment site to encourage wetland vegetation re-establishment. Fencing of this structure
Comanche Creek Native Trout Habitat Restoration Project Appendix A 2
may be necessary to prevent damage by trampling or consumption by large ungulate grazers (elk and
livestock).
Sheet Piling Dams are metal structures that are pounded into the drainage channel and adjacent floodplain
to establish a grade control height. These structures are installed by using heavy machinery and can be
adjusted in height over time either by cutting or adding to it. This treatment method would be used to
anchor the gradient change of a perennial stream channel where associated expansive wetlands are in
danger of permanent loss due to incision of the perennial water channel. Large rock rip rap and graded
aggregate would be used downstream of the sheet piling to dissipate water energy and to protect the sheet
piling structure. Construction would require an excavator to prep the site and install the large rock rip rap
and graded aggregate. Small dump trucks (10 yard capacity) would be used to deliver rock material.
Maintenance of these structures may be needed over time to repair the effectiveness of a given treatment.
Maintenance would include adding new material to the treatment site, rearranging existing materials,
and/or the addition of mulch or fencing to protect the site until it is stabilized.
Headcut treatments
Many of the gullies and eroded channels found in tributaries of Comanche Creek are started by a headcut
(headward, or upstream cut). A headcut is a steep, eroding cut through the wetland soil that concentrates
water flow and causes a plunge pool to develop at the base of the cut. Through a combination of splash
erosion of the falling water, freeze and thaw erosion, and soil piping, the soil at the face of the headcut is
constantly eroding and being carried downstream. As the headcut moves up-valley, the channel that has
eroded becomes a gully and the water table drops to the bottom elevation of the headcut. The headcut
causes the soil area upstream and adjacent to the headcut to become drier; the vegetation weakens due to
water stress, roots become exposed, desiccate, and dieback. The erosive face of the headcut expands
laterally and advances upslope because the root masses have died back and are no longer able to bind soil
particles.
A number of headcut treatments have been proposed to address the concentration of water at the headcut
and re-vegetate the bare soil at the slope of the headcut. These treatments include; Worm Ditch, Zuni
Bowl, Rock Mulch Rundown, Log and Rock Stepdown, Straw Bale Filter Dams, and Earthen/Aggregate
Fill and Mulch Cover. Each of these techniques repairs the headcut by a combination of effects that
redirect surface flow away from the headcut, by reducing the concentration of water at the headcut, and
removing the erosive force of the water drop from the top of the headcut to the bottom of it. The final goal
of all of these treatments is a wider, gently sloping channel that can grow wetland vegetation that resists
headcut erosion. In the case of Straw Bale Filter Dams, only weed free certified straw will be used.
Maintenance of these structures may be needed over time to repair the effectiveness of a given treatment.
Maintenance would include re-digging or cleaning out a worm ditch, adding new material to the treatment
site, rearranging existing materials, and/or the addition of mulch or fencing to protect the site until it is
stabilized.
Channel reinstatement techniques
In addition to the progression of headcuts, many of the swales, wetlands and channels in the Comanche
Creek drainage and tributaries are impaired by gullying and channel erosion due to old roads, cattle trails
or road crossings. Formerly healthy slope wetlands have downcut to a narrow gully channel with a trickle
of water, effectively dissecting the wetland and causing a net groundwater loss. The most effective and
productive restoration techniques involve restoring the water to its former channel and elevation by a
number of channel reinstatement techniques. These techniques include Channel Plug, Plug and Pond,
Worm Ditch, and Historic Meander Channel.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 3
Each situation is unique, but all involve blocking or restoring the headcut of the gully with a grade control
or headcut treatment, and a channel reinstatement technique to restore the water to its former channel
elevation. The channel reinstatement raises the water table to its pre-impact (historic) level and restores
groundwater storage capacity in the adjacent stream banks and wetlands. These techniques have the
capacity to create many acres of wetlands downstream of the treatment. The wetlands upstream of the
headcuts are also protected by these techniques, as the headcut is starved of the erosive forces.
Maintenance of these structures may be needed over time to repair the effectiveness of a given treatment.
Maintenance would include re-digging or cleaning out a worm ditch, relocating the treatment site as the
treated area responds to the treatment, adding new material to the treatment site, rearranging existing
materials, and/or the addition of mulch or fencing to protect the site until it is stabilized.
Deflector Treatments
The Induced Meandering stream restoration techniques use the power of flowing water and sediment to
re-meander a channel that has been straightened. Deflector treatments induce the channel to meander in a
Sine wave pattern. A meandering channel initiates the evolution of a healthy stream channel, creates and
expands floodplains, and increases alluvial storage. Sediment builds point bars, increasing the amount of
healthy riparian vegetation, leading to a reduction in water temperature due to shade. The force of
floodwaters is dispersed by the meandering form of the channel and by erosion against the outside
meander bends, and the downward force of the channel is reduced, preventing gullying and downcutting.
Meandering channels are found only when the slope is less than 4% and usually less than 2%. These
techniques will be used only in the flattest tributaries and the main channel of Comanche Creek. The
deflector treatments used include Post Vanes and Picket and Boulder Baffles.
Maintenance of these structures may be needed over time to repair the effectiveness of a given treatment.
Maintenance would include extending the treatment site as the treated area responds adding new material
to the treatment site, rearranging existing materials, and/or the addition of fencing to protect the site until
it is stabilized.
Live Vegetation
Many of the erosion features in the Comanche Creek watershed can be repaired in part or wholly by
planting live vegetation to anchor soil and arrest headcutting. This includes the use of wetland sod mats,
wetland sedge plugs, live willow fascines, live pole plantings. Most techniques used in the watershed will
include some live vegetation as “finishing material”. The vegetation will mostly be obtained on-site from
an area that will quickly re-grow by clonally propagated wetland vegetation. Source material could also
come from a USDA Plant Material Center and/or use of commercial sources of materials that fit within
the species composition that naturally occur in the area. Willows and cottonwoods will be obtained
nearby within the watershed from an area that has sufficient quantities.
Maintenance of these live vegetation plantings may be needed over time to replace material that died due
to planting shock and to effect the repair of a given treatment. Maintenance would include re-digging and
replanting live material on the treatment site, adding new material to the treatment site, rearrangement of
existing materials, and/or addition of mulch or fencing to protect the site until it is stabilized.
Seeding and Mulching
All the restoration techniques used in the Comanche Creek watershed may benefit from re-seeding and
mulching techniques. Seeding treatments include native seed mixes, and seed mats. Mulch will typically
be some form of certified weed free native straw or hay from a wetland grass hay source but may also
include woodchips, shredded wood fiber, jute netting, coarse woody material (crushed branches to small
Comanche Creek Native Trout Habitat Restoration Project Appendix A 4
logs) and even soil or aggregate cover. The seed mixture will include a number of species native to the
area.
Application of seed will use broadcast methods such as backpack or hand spreaders if the area is small in
size. All treatment sites are typically small (less than 0.5 acres) in size. The cumulative acreage of sites
treated in a given year could potentially justify use of a hydro seeder/mulcher. Use of a hydro
seeder/mulcher would likely be rare in occurrence and would be restricted in use due to road access
limitations.
The mulching techniques will provide shade, conserve soil moisture and protection from the elements so
that the seeds will germinate and survive easily. Mulching will also ultimately increase the organic
content of the soil at the treatment site and aid in restoration of the vegetation at the site. Mulch materials
will be weed free and may include a variety of either natural or manmade materials such as straw, hay
(from wetland or riparian pastures), jute netting, gravel, soil high in organic matter, coarse shredded wood
fiber/chips.
Maintenance of seeding and mulching areas may be needed over time to repair the effectiveness of a
given treatment. Maintenance would include re-seeding and/or re-mulching a site until it is stabilized.
Maintenance would also include monitoring of seeded sites for the presence of noxious weed species.
Wetland species that may be used include: Aquatic sedge (Carex aquatilis), Nebraska sedge (Carex
nebraskensis), Ovalhead sedge (Carex microptera) and Millet woodrush (Luzula parviflora). Riparian
species that may be used include: Alpine timothy (Phleum alpinum), Tufted hairgrass (Deschampsia
caespitosa), and Ovalhead sedge (C. microptera). Upland species that may be used include: Thurber
fescue (Festuca thurberi), Idaho fescue (Festuca idahoensis), Mountian muhly (Muhlenbergia montana),
Timothy (Phleum pratense), Muttongrass (Poa fendleriana), and Threadleaf sedge (Carex filifolia).
Fencing Treatments
Many of the erosion control and channel restoration treatments that will be implemented at Comanche
Creek will need to be surrounded by fencing to prevent elk and cattle from harming the treatment site or
eating the mulch or new vegetation that is responding to the restoration technique. In some cases fencing
alone would be the restoration treatment for the site to allow impacted soils and vegetation to recover
from historic impacts regardless of source of impact. Construction of fence sites may require either use of
hand tools and hand labor or may include use of a pickup truck, to deliver materials, and tractor or
backhoe to dig or fill post holes.
Some of the treatments may only require temporary fencing for a short duration (5 to 10 years) until the
restoration treatment is complete. Other fencing treatments may become a permanent feature since it
protects a key location of springs, seeps, or unique wetlands such as fens that are fragile to ungulate
impacts.
Drift Fencing will also be used as a restoration technique to protect stream meander bends from livestock
while they move between pastures. This technique forces grazing animals, elk and cattle, to meander their
trails and minimize the impact on landform and surface flow patterns. Short segments of fence placed
parallel to eroding banks deter trampling and encourage revegetation. The fencing techniques that will be
used at Comanche Creek include Post and Pole Fencing, Post and Wire Fencing, Drift Fencing, Hemi
Fencing and Exclosure Fencing.
Maintenance of these fence structures may be needed over time to keep them protecting a treatment area.
Maintenance would be needed to repair damage caused by normal weathering and by damage caused by
animals, humans, and flood events. Maintenance would include replacement of fence materials and posts
Comanche Creek Native Trout Habitat Restoration Project Appendix A 5
and may include changing the size and shape of a fencing area to adjust to: vegetation growth due to
treatment, change in trailing patterns by ungulates due to structure placement. Maintenance may also
include use of a tractor or backhoe to deliver materials and dig/fill posthole locations.
Road Treatments
The erosion found in the tributaries of Comanche Creek was caused by historic land uses that
concentrated water and created the conditions for headcutting and gully erosion. Many of the historic
trails and roads remain and continue to concentrate water and cause erosion downstream and upstream of
the trail or road. The solution to this water concentration is to control the grade of the erosion and re-
spread the water across the landform.
The road treatment techniques that will be used include Earthen/Aggregate Fill and Mulching (of road
cutbanks), Rolling Dip, Sediment Traps, and Road Crossing/Hardening Repair (Armored Cross Drains)
and Water Bars. These techniques have been used in many places in the Valle Vidal and have survived
seasons of erosion and runoff. The Earthen/Aggregate Fill and Mulch and Rolling Dip techniques are
typically built out of native soil, while the Road Crossing Repair technique generally requires an amount
of rock aggregate fill for stabilizing the roadbed within the drainage channel. Sediment traps are small
catch basins constructed to collect road drainage in areas where there is insufficient vegetative buffer to
filter road born sediments before it reaches perennial waters.
All of these techniques typically require the use of heavy equipment such as a light duty bulldozer and/or
a backhoe to transport material and shape it to meet the design of the site. On occasion, a heavy duty
trackhoe might be needed depending upon the size of the material needed and treatment site conditions. A
small 10-yard dump truck will be used to haul needed aggregate/soil material to the treatment sites.
Maintenance of these structures may be needed over time to repair the effectiveness of a given treatment.
Maintenance would include re-shaping rolling grade dips on roads, and repairing road drainage crossings
that may degrade over time due to water flowing in the drainage channel. Maintenance would typically
require using heavy equipment such as a light duty dozer, backhoe and/or a trackhoe for sites that need
major repair. Maintenance would also include adding new material aggregate material to the treatment
site, rearranging of existing materials, and/or the addition of mulch or fencing to protect the site until it is
stabilized.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 6
Treatment Diagrams
Grade Control Structures
Rock Check Dam
Rock Check Dams are used when it is necessary to slow the flow of water across a swale or channel. In
addition to slowing the velocity of concentrated flows, they also capture sediment from the drainage area.
These Rock Check Dams are most effective when used with other erosion control measures.
One Rock Dam
A One Rock Dam is a grade control structure that works to reduce water velocity, shear stress, and scour
depth. The structure is one rock deep, several rows wide, wide as bankfull width, and no taller than 1/3
the channel’s bankfull depth. Rocks are uniform in size, with gaps between rocks filled to the vertical
level of the structure with small rocks and gravel. This chinking helps stabilize the structure until the
interstice spaces fill with fine bedload particles. This final filling will provide a substrate for subsequent
vegetation which will further anchor the structure to the channel.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 7
A Filter Weir (Rock Check Dam/Boulder Weir) is designed to raise the bed of a gully by trapping
sediment. It is used when the channel bed is primarily gravel or cobble. These are built in three sections
from several parallel rows of boulders placed in a channel bed at right angles to the direction of water
flow.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 8
Media Luna
A Media Luna is used to disperse water flow from sheet erosion. “Sheet flow spreaders” have the tips up
to disperse channelized flow while the “Sheet flow collectors” are constructed tips down to create a
transition between sheet flow and channelized flow at the head of rills and gullies.
Straw Bale Filter Dams (Straw Bale Falls) are suitable for the remediation of small headcuts. These act
to reduce the impact of water by forcing it to move more slowly through the porous structure. The straw
bale is a suitable media for growth of wetland vegetation. Consider that wildlife and livestock will graze
the bales of the structure and plan to fence the site accordingly.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 9
Headcut Treatments
A Worm Ditch (also called a Bypass Channel) is constructed to starve a headcut of the water that is
causing excessive erosion. A Worm Ditch is started above the headcut in a valley broad enough to allow
for space for the Worm Ditch between the down-cutting channel and the hillslope. The length of the
worm ditch should be two times the length of the valley channel. The re-entry point to the down-cut
channel should be well armored with rock or a Zuni Bowl.
A Zuni Bowl is made of rock-lined step falls and plunge pools that prevent a headcut from
continuing to migrate upstream. They dissipate the energy of the falling water by forcing the
water to go over a series of smaller step falls.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 10
A Rock Mulch Rundown is a treatment that armors the channel and associated banks of a head cut with
rock. This treatment can be used when the vertical face of a headcut can be sloped back resulting in a
more gradual gradient that reconnects the flow of the stream in the channel.
The channel is armored with rock to dissipate energy, mitigate erosion of stream banks, and to prevent
further down cutting of the channel. This structure can also be used to prevent head cutting in a channel
segment that is over-steepened compared to the valley slope. Channel banks should be armored to at least
a point that is above bankfull and preferably to the break in slope onto the channel’s flood plain. The
mulching, moisture retention effect of the rock also promotes re-vegetation of exposed channel banks.
These are uses only in low-energy headcuts.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 11
The Log and Fabric Step Fall structure is designed to control headcuts that are advancing through
wetland or wet meadow soil. Establishment of vegetation will stabilize the edge of the headcut. Geotextile
fabric is optional and dependent upon soil type and headcut severity.
Straw Bale Filter Dam (see diagram and description above in Grade Control Structures section)
Comanche Creek Native Trout Habitat Restoration Project Appendix A 12
Sheet Piling Dam
The Sheet Piling Dam is used to control stream or channel gradient by establishing a fixed height to a
point in the channel. This type of treatment requires heavy equipment to install (to pound interlocking
sheets of metal) into the ground across the stream channel and tied back into the elevation of the 1st or 2
nd
terrace floodplain bench. These structures are adjustable and can accommodate changes in height. The
purpose of these dams are not to retain or dam up water but to stop in channel incisement and capture
sediments to re-establish upstream wetlands and increase groundwater accumulation.
Earthen Aggregate and Soil Mulch
The Earth Aggregate Soil and Mulch treatment addresses the erosion and progression of a head
cut by filling the eroded, incised channel up to the slope of the original channel and its floodplain
with a combination of rock, straw, or woody debris such as tree limbs. The surface area can be
seeded with native seed, seed mats, or left unseeded to allow natural re-seeding. This treatment’s
maintenance needs will the assessed by periodic site visits. Maintenance for this treatment
includes re-seeding, re-mulching, and re-filling of any treatment area experiencing erosion.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 13
Channel Reinstatement Treatments
Rock Plug
A Rock Plug is a rock or boulder structure installed in the incised channel which directs base stream flow
into a new channel or onto an abandoned wet meadow. The size of the material used is based on, and
seeks to match, depth of stream base flow. The structure will allow flood waters to enter the abandoned
channel resulting in increased flood plain and wetland area. Generally, one channel plug is installed at the
channel diversion and one at the downstream confluence with abandoned channel. The downstream Rock
Plug keeps the base flow from migrating up the abandoned channel. By allowing the stream access to its
original flood plain elevation, this treatment can also be used to treat headcuts upstream of the structure.
This effect is realized when the return to the original stream elevation eliminates or reduces the vertical
drop of the steam at and immediately below the spillover point of the headcut.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 14
Plug and Pond
The Plug and Pond treatment is a method of slowing channel flow enough with a channel fill plug that
will temporarily pond water upstream of the plug.
Worm Ditch (see see diagram and description above in Headcut Treatments section)
Comanche Creek Native Trout Habitat Restoration Project Appendix A 15
Historic Meander Channel Reinstatement
A Historic Meander Channel Reinstatement uses a single-layer rock or boulder structure installed in
the incised channel to direct base stream flow into the original channel or wetland. The size of the
material used is based on, and seeks to match, the depth of stream base flow. The structure will allow
flood waters to enter the abandoned incised channel resulting in increased flood plain and wetland area.
Generally, one channel plug is installed at the channel diversion and one at the downstream confluence
with abandoned channel. The downstream channel plug keeps the base flow from migrating up the
abandoned channel.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 16
Deflector Treatments
Post Vanes are used for two different results. They may be used to deflect high velocity flow away from
a cut bank of a meander bend in order to lessen bank erosion or they move the highest velocity of water
flow away from the bank. Another use of post vanes is to induce channel meandering by directing flow
into the opposite bank causing bank erosion and widening the channel in that direction.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 17
A Picket Baffle acts as a deflector to create lateral erosion of a streambank to widen the channel. It
concentrates flow on the opposite bank and increases stream velocity, thereby decreasing stream velocity
on the adjacent bank. This increases sediment deposition along the adjacent bank which initiates the
formation of a point bar.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 18
A Boulder Baffle acts as a deflector to create lateral erosion of a streambank to widen the channel. It
concentrates flow on the opposite bank and increases stream velocity, thereby decreasing stream velocity
on the adjacent bank. This increases sediment deposition along the adjacent bank which initiates the
formation of a point bar.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 19
Live Vegetation
Willow Plantings are used to increase or decrease the erosion or deposition of parts of the channel
depending upon the meander design objectives.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 20
Drawing from Riparian Management on the Bosque del Apache National Wildlife Refuge, J.P. Taylor
and K. C. McDaniel
Pole Plantings will be used to establish Narrowleaf cottonwood trees in select locations.
Willow Fascine
Diagram from http://prairiepiece.wordpress.com/
Willow Fascines are long bundles of willow stems buried in shallow trenches that run parallel to stream
flow. The bundles are constructed from live stems that are tied together. When the plant bundles sprout,
they develop a root mass that anchors the streambank.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 21
Fencing Treatments
Post and Wire Exclosure Fence
A Post and Wire Exclosure is constructed to keep large animals out of the riparian area while allowing
small animals to move through the exclosure. The exclosures keep both cattle and elk off the creek banks
to allow for recovery of native herbaceous vegetation and willows.
Channel Crossings are designed to allow for passage of water and flood-borne materials along the
stream channel without damaging the exclosure fence.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 22
From Zeedyk and Wells, 2006
Hemi Fence is placed on the outside edge of stream meanders to protect riparian vegetation from grazing
impacts by large ungulates. The design exploits the behavioral tendency of cattle to graze the vegetation
in these meander bends and riffle areas rather than areas with deep pools and steep banks. Another
advantage is that these can be used instead of full exclosures.
Drift Fence
Drift Fence, or livestock fence, prevents livestock movement into areas that that are restricted based on a
grazing management plan. A section of drift fence can be placed on the meander bend of a creek to
prevent cattle trampling the creek bank.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 23
Roads
Rolling Dip
Rolling Dips are created in roads to modify the drainage patterns. They allow surface flows to be
dispersed across the roads frequently enough to prevent large, concentrated flows.
Sediment Trap
A Sediment Trap is constructed for the temporary collection of storm water. Sediments in the storm
water settle during water infiltration in the trap.
Comanche Creek Native Trout Habitat Restoration Project Appendix A 24
Road Crossing/Hardening Repair (Armored Cross Drains)
Road Crossing/Hardening Repair (Armored Cross Drain) functions to capture water draining from
the road and release the water in a controlled manner. A dip in the road that is approximately the width of
the channel is armored to prevent scouring. These should be placed at intervals that are close enough to
diffuse concentrated volumes of water draining from the road surface.
Water Bar
From Moench and Fusaro, 2012, www.colostate.edu/Depts/CSF
Water Bars are soil or rock berms that channel water flow off roads and trails. The berms (or bars) are
angled downslope to the outlet side.