EPA-660/3-74-009
JUNE 1974
Ecological Research
Environmental Guidelines for Develop
ment Roads in the Subarctic
National Environmental Research Center
U.S. Environmental Protection Agency
Office of Research and Development
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ECOLOGICAL
RESEARCH series. This series describes research
on the effects of pollution on humans, plant and
animal species, and materials. Problems are
assessed for their long- and short-term
influences. Investigations include formation,
transport, and pathway studies to determine the
fate of pollutants and their effects. This work
provides the technical basis for setting standards
to minimize undesirable changes in living
organisms in the aquatic, terrestrial and
atmospheric environments.
For gale by the Superintendent of Documents, U.S. Government Printing Office, Washington, B.C. 20402 - Price $1.15
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EPA-660/3-74-009
June 1974
ENVIRONMENTAL GUIDELINES
FOR
DEVELOPMENT ROADS IN THE SUBARCTIC
by
Frederick B. Lotspeich
Arctic Environmental Research Laboratory
College, Alaska 99701
and
Austin E. Helmers
U.S. Forest Service
Institute of Northern Forestry
Pacific Northwest Forest and Range Experimental Station
Fairbanks, Alaska 99701
Project 21ARX
Program Element 1BA021
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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ABSTRACT
This set of guidelines Is based on Federal and State regulations
that set standards to protect the total environment. Although major
highway construction 1s under stringent regulation, pioneer type access
roads such as are needeftsbjHaggers, miners, land developers, etc. have
been neglected. These-"smaller roads frequently pose serious erosion
hazards because pianmrig,-design, and construction of them is not
thorough, as it is for major roads; this results in erosion, fire and
insect traps, and generally unattractive roadways.
Suggestions and recommendations contained in these guidelines are
for the use of operators with limited engineering and planning staffs.
Although all examples of poor practices are from the vicinity of Fairbanks,
all suggested treatments are taken from the literature from the conterminous
United States, with some modifications for subarctic conditions. Most of
these recommendations are simple in concept, and 1f properly applied, do
prevent erosion and result in superior access roads which are esthetically
pleasing.
ii
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CONTENTS
Page
Abstract i i
List of Figures v
Acknowledgments vi i
Preface viii
Conclusions 1
Introduction 2
Objectives 2
Scope 2
The Substrate 3
Recent Federal Legislation 3
Planning and Route Selection 7
Road Design 12
.Road Prism and Gradient 12
Spur Roads 20
Drainage 20
Erosion Control 27
Construction 35
Surveying and Right-of-Way Clearing 35
Earthwork 40
Support Activities 42
Restoration 43
Road Maintenance 46
Putting Roads to Bed 49
Guidelines for Putting Roads to Bed 49
iii
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Page
Roads on Muskegs 52
Introduction 52
Muskeg Properties 52
Road Construction 52
Ice Bridges 55
References 60
iv
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LIST OF FIGURES^
N£« Page
1 Access Road Erosion 4
2 Erosion of a Roadside Ditch 5
3 Winter Haul Road 8
4 Summer Haul Road 9
5 Short Log Yarding 10
6 Haul Road Erosion 13
7 Haul Road Erosion 14
8 Cross Drainage 15
9 Rilling of Outsloped Reach 16
10 Cross Drainage 17
11 Low Gradient Logging Roads 18
12 Old Maintenance Road 18
13 Road Drainage Diversion 19
14 Erosion Control Devices 21
15 Skidtrail 21
16 Erosion of Skidtrail 22
17 Improperly Designed Access Road 23
18 Deep Gully in Access Road 24
i
19 Improperly Installed Culvert 24
20 Erosion Control Devices 25
21 Culvert Installation 26
22 Open-top Culverts 27
J/All photographs except Figures 40-42 are by the authors.
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Ho. Page
23 Construction Techniques 27
24 Control Measures 29
25 Drains 30
26 Logging Debris 31
27 Debris 32
28 Vegetation Mat 33
29 Ice Bridge 34
30 Proper Right-of-Way Clearing 36
31 Berm Piles Left by Bulldozer Clearing 37
32 Forest Haul Road 38
33 Haul Road 39
34 Erosion 41
35 Stabilization 44
36 Rock Armor in Ditches 45
37 Mechanical Clearing of Brush 47
38 Selective Cutting 50
39 Re-establishment of Trees on Old Road 51
40 Ice Bridge 56
41 Timber Reinforcement 57
42 Pumping Water 58
vi
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ACKNOWLEDGMENTS
Many people contributed to this report through discussions and
ideas. Particular thanks are due to Mr. Royal Hanson (State of
Alaska Division of Lands, Fairbanks), who outlined specific recom-
mendations, Mr. Roger Bolstad (Bureau of Land Management, U.S.
Department of the Interior), who added his experiences with erosion
control and with slope stabilization, Dr. John Zasada (Institute of
Northern Forestry, Fairbanks), who provided first-hand observations
on logging road construction and maintenance, Mr. Dean Cummings
(Delta Junction), who discussed winter logging with the authors,
and Mr. Patrick Finnegan, Land Use Specialist, Fairbanks North Star
Borough Planning and Zoning Department.
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PREFACE
"Environmental Guidelines for Road Construction in Alaska," by
Dr. Frederick B. Lotspeich, was published in 1971 to "...describe
the best practical measures required to assure environmental pro-
tection during road construction under cold climate conditions."
The report that follows has a similar purpose, but with particular
emphasis on logging and other pioneer type development roads.
This report is essentially a collection of guidelines that, it is
hoped, will serve to emphasize the need to consider road planning
at the same time that resource developments are planned. The
suggestions provided here are not based on research in Alaska.
Instead, they are an amalgam of observations, ideas, and recommen-
dations from a number of people involved in timber sales, zoning
and planning, and land management; intended to be a helpful guide
until definitive road standards for Alaskan conditions can be
developed through research and experience.
The authors hope that resource managers and timber sale administrators
alike will share ideas for improved access road construction and
maintenance—in the interest of beneficial resource use while main-
taining a quality environment for all other resource uses.
vili
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CONCLUSIONS
Ecological systems in the subarctic characteristically are in a state
of delicate balance. Small changes in one environment can profoundly
affect many other factors, and for a long time. Accordingly, disturbances
such as pioneer access roads, common to most rapidly developing areas,
must be carefully planned to prevent undesirable environmental damage.
In the sensitive ecosystems of the subarctic, such damage can be of large
scale, far-reaching in its effects, and sometimes virtually irreversible.
Key points in access road design, construction, and maintenance relate
to site and road drainage, to right-of-way clearing, and to maintenance:
1. Road planning should include consideration of long-range area
management objectives, and should take advantage of planning tools
such as maps, aerial photography, and engineering advice.
2. Permafrost should be avoided, or crossed high on slopes, where
bedrock is near the mantle surface.
3. Right-of-way timber should be cut close to the ground, into the
right-of-way, and away from streams. The surface material disturbance
caused by bulldozers can be avoided with hand clearing. The cleared
width should be a minimum. The organic mat should be undisturbed,
if possible. This is very important over muskegs and permafrost,
where the cleared material also should be placed under the fill.
Heavy equipment should be kept off the right-of-way.
4. Proper drainage is one of the most important factors. Design
an outsloped roadway, if possible, consistent with loads to be
moved. If drain ditches must be used, runoff should be inter-
cepted at frequent intervals to avoid build-up of erosive power.
Runoff should be carried across the road to stable slopes. Designs
such as open-tops, rolled grades, cross drains, or shallow ditches
usually are suitable drainage structures.
5. The road should be maintained during use, to preserve adequate
drainage, and thus to reduce erosion and sedimentation.
6. Wood and culverts should be removed when road use is finished.
Open-tops should be removed and replaced with gravel cross drains.
Erodible areas should be stabilized by planting and fertilizing.
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INTRODUCTION
OBJECTIVES
In 1971 "Environmental Guidelines for Road Construction in Alaska,"
by Dr. Frederick B. Lotspeich, was published to "...describe the
best practical measures required to assure environmental protection
during road construction under cold climate conditions." The
report that follows has a similar purpose.
The objectives of these guidelines are to collect, compile, and make
available to resource managers and operators, and to others who need
development roads in the subarctic, the methods, procedures, and engi-
neering principles that will permit road access with minimum damage
to the resource base. The principal aim is to focus on unique problems
associated with the cold-dominated environment as they would influence
access road building. An ancillary purpose is to distribute such
information to other segments of the public to inform them about
acceptable pioneer road practices and why and how such activities can
be performed without undue damage to the environment.
SCOPE
This report is a collection and summary of road related practices,
with emphasis on resource development roads which meet environmental
protection requirements. Many acceptable practices in warmer climates
can be used where permafrost occurs if proper restrictions or modifi-
cations are used to prevent unwanted thawing and thermal erosion. It
is not enough to prevent erosion as a soils-saving measure; it also
must be controlled to prevent water degradation by sedimentation.
Engineering efforts associated with pioneer road construction are
usually minimal because many developments are small. This guide
contains—and refers to—engineering experience, procedures, and
criteria to assist the small operator in applying sound procedures
to route selection and to building pioneer access roads.
The suggestions provided here are not based on our research in the
subarctic. Instead, they are an amalgam of observations, ideas, and
recommendations from a number of people involved in timber sales,
zoning and planning, and land management; and are intended to be
a guide until definitive road standards for northern conditions can
be developed through research and experience. The authors hope that
resource managers, timber sale administrators, miners, and contractors
alike will share ideas for improved access road construction and
maintenance—in the interest of beneficial resource use while main-
taining a quality environment.
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THE SUBSTRATE
All of interior Alaska is within the zone of discontinuous permafrost.
Many south slopes and valley areas are frost-free, but many low-lying
areas and all colder slopes are underlain by discontinuous to con-
tinuous permafrost. Roads built on such terrain may be unusable
during the summer season and can erode rapidly.
Mature forests have a well-developed duff layer that adequately pro-
tects the soils from erosion if undisturbed. However, logging, mining,
and subdivision development, with their associated road building,
uncover the mineral soil by removing the organic layer and expose
the poorly aggregated soil to water erosion. Most of these operations
are small and isolated from public view, and erosion may be active
during and following a development operation unless corrective steps
are taken. Land subdivision access roads are exposed to view but
often with no erosion prevention practices (Figures 1 and 2).
RECENT FEDERAL LEGISLATION
Water pollution legislation before 1965 was largely ineffectual and
emphasized water supply and sewage treatment. The Water Quality Act
of 1965 created a new organization within the Department of Health,
Education, and Welfare devoted to pollution control and set up a
system for state water quality standards subject to Federal approval.
The Act of 1965 amended the Act of 1956 and also provided for research
and made funds available through grants for construction of treatment
plants and demonstration projects. This organization was transferred
to the Department of the Interior in 1966.
In 1966 the Clean Water Restoration Act was passed, which emphasized
the need for immediate cleanup with provisions for Federal assistance
to municipalities in funding treatment plants. The Water Quality
Improvement Act was passed by Congress in 1970, which strengthened
the previous laws. A complete reorganization of a number of agencies
in the Executive Branch having environmental responsibilities was
accomplished in 1970, with the formation of the Environmental Protection
Agency. This reorganization placed the responsibility for most environ-
mental activities within one agency and includes water, air, solid
waste, radiation, pesticides, and noise pollution.
The Federal Water Pollution Control Act of 1972 includes water controls
and sets dates for compliance to standards.
These actions by Congress and the President were in response to a
growing awareness that environmental damage is severe and that
preventive measures are urgently needed. It also indicates that
an informed, articulate public recognizes that the environment is
composed of many interrelated, interacting elements that must be treated
as a system instead'of individual elements.
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.
Figure 1. An access road for a private subdivision a few miles north of Fairbanks. Two serious
deficiencies are evident in this photo: no effort at proper drainage and no road main-
tenance, even though this photo was taken near the end of the summer in 1973.
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en
Figure 2. Another example of erosion of a roadside ditch on another private subdivision off Steele
Creek Road north of Fairbanks. Proper drainage would have prevented this unsightly gully
from forming.
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The National Environmental Policy Act of 1969 (NEPA), while not directly
emphasizing pollution, states the broad objectives of our national
policy toward the environment and establishes a permanent Council on
Environmental Quality. A very important provision of the NEPA is the
requirement that if any major action by a Federal agency is likely to
significantly affect the environment, the agency shall prepare a
detailed statement on the impact of this action. Moreover, it includes
the stipulation that major action of other organizations supported by
Federal funds shall also require an environmental impact statement.
Thus, it becomes apparent that a large percentage of proposed activities
require environmental impact statements, either because it is a direct
Federal activity or is federally funded.
Since most of man's activities disrupt the environment to some degree,
any planned action should be conducted with forethought toward mini-
mizing this damage. Various measures to implement, regulate, and set
standards are mentioned in the cited Acts. What now remains to be
accomplished is to devise, with these tools, the methods, guidelines,
and procedures that will accomplish the task without undue impediment
to operators. This can best be done when the individuals responsible
are convinced that the environmental way is the preferred way and
that regulations are not intended to restrict, but to expedite, a
better way of life for all, now and in the future.
With the new public awareness of the need for environmental protection,
an increasing number of road construction contracts probably will
include stipulations and recommended procedures to prevent erosion
damage to water and soil resources.
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PLANNING AND ROUTE SELECTION
Planning for a development operation must consider the long-range
management goals, because these goals will influence road layout.
A logging contract, for example, should include a brief statement
of management policies. Early mention of these will prevent mis-
understanding and help to achieve the proper resource management.
Plans for harvesting small timber stands adjacent to access roads
(Figures 3, 4, and 5) may not require more than a few notes. More
complex, longer-term logging or land development operations require
detailed road layouts as part of the contract, or plan, to avoid
confusion and comply with environmental requirements. The Industrial
Waste Guide on Logging Practices (FWPCA 1970) contains many suggestions
on timber harvesting which can be applied to Alaska.
Both aerial photos and topographic maps are useful in planning
road layouts, with all routes checked by ground reconnaissance. This
last step is important and will pay off in avoiding problem areas that
do not appear on maps. The complete road net should be planned sys-
tematically instead of one step at a time; it has been shown that
haphazard road planning results in more mileage and greater damage
from erosion and sedimentation.
Areas having soils that are susceptible to slides and slumps, excessive
settlement, severe erosion, and soil creep should be avoided wherever
possible. Areas of permafrost should be avoided if at all possible,
and alternate routes explored even if some additional distances are
involved. A short section of thawing permafrost may cause serious
maintenance problems, damage to resources, and increased operating
costs. Generally the costs of building on sloping, frozen ground,
and the attendant damages, outweigh most benefits. When the resource
to be used is located on slopes, the main roads should be located as
far upslope as possible. There the soils usually are shallow over
bedrock and/or more resistant to erosion. North slopes should be
avoided since most of these exposures are frozen, even near the
ridge crests. Intensive thermal, or permafrost, reconnaissance may
show that some north slopes can be used for roads near the crests
if bedrock is near the surface.
i
A completed route map based on map and ground reconnaissance
should accompany any contract application and be approved before cutting
or construction commences. This route map need not be based on a
sophisticated survey; frequently an Abney level traverse is sufficient,
but grades, drainage, and borrow areas should be clearly indicated.
In locating roads, consideration must be made of the equipment which
will use them, and sufficient radius allowed on turns to accomodate
the longest vehicle. Long steady grades are to be avoided; if they ara
present, they should be broken with short sections of level or reverse
grades. These measures prevent the accumulation of excess drainage water
at points likely to erode and permit wider distribution of runoff
with concentrations at only a few points.
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00
.., •
>
r
Figure 3. Winter haul road on a flood plain. Such a road requires minimum engineering and con-
struction effort. Erosion is minor, even without treatments, because the terrain is
flat. (Gerstle River)
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Figure 4. Summer log haul road traversing a 10-20 percent slope. It is an example of adequate
right-of-way clearing and of construction standard for winter or dry weather hauling,
(Bonanza Creek Experimental Forest, west of Fairbanks)
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Figure 5. Late winter short log yarding in a flood plain forest. Keeping yarding distance to a minimum
results in more distance in truck trails. Compensation occurs through short logs, smaller loads,
and winter logging. The significance of yarding distance is due to lodgement of alluvial silts in
the bark of logs, and consequent rapid saw wear. Winter logging reduces the silt load, but even
wind deposited silts are a problem. (Gerstle River)
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Each operation or development will be unique, and protective measures
must be located and designed for each project or contract. Also
included in the plan should be descriptions of protective measures
to be accomplished to avoid erosion and unnecessary disturbance of
the soil.
11
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ROAD DESIGN
Several factors control the design of access roads. A well-selected
route will avoid obvious problem areas, although some unforeseen
problems may arise. Design of a road located far from problem areas
is routine, because natural drainage characteristics can be determined
from maps, and proper drainage structures can be engineered to provide
for disposal of water. Field observations show that the most serious
oversight in planning access roads is inadequate drainage. Melt and
rain water must not be permitted to accumulate in bar ditches or on
the roadway. However, even the best route may have sections requiring
special designs.
Projected loads, size of the operation, and anticipated use of the
road all influence ultimate design. The road should be designed with
these in mind and extra attention given to problem areas because all
portions of the road must meet the same load requirements. Long-log
hauling with "semi's," for example, will have different curve require-
ments than will short-log hauling. Small operations with few vehicles
may not need a two-way road; one with many vehicles may require wide
roads or many turnouts for passing. Design specifications should be
apparent in the contract and resource management plan.
Final disposition of the road after the development is completed must
be considered; is it to be put to bed, or will it remain in use, for
example, as public access to new recreation areas.
ROAD PRISM AND GRADIENT
Although gradient is controlled by location and topography, local
variations should consider drainage structure requirements.
1.- Have fill slopes with less gradient than the angle of repose
for the given material.
2. Design a gentle outs!ope on roads that do not have Inner drainage
ditches (Figures 6, 7, 8, 9, 10, and 11). Outsloplng permits
drainage of melt water over the outside edge of the roadway
without channelling parallel to the roadway. On cut and fill
in wind-deposited silts, design vertical cuts, intercept runoff
above the cuts and conduct it to natural drainageways that provide
adequate erosion protection. Figure 12 shows a potentially
dangerous, but in this case, successful design. Figure 13 shows
a water diversion successful for entrenched roads, such as shown
in Figure 12. '
i
3. Keep grades to less than 6 percent, except for short distances
where as high as 10 percent may be allowed for unusual conditions,
such as entering a natural drainage.
12
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Figure 6. Erosion of this log haul road was rapid despite the gravel content of the soil--runoff
from spring breakup was concentrated on the inner edge of the road. Cross drainage is
needed. Near Fairbanks, Alaska.
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-
Figure 7,
Erosion in silt soil; same road
would have prevented the gully.
as in Figure 6. Cross drainage
Near Fairbanks, Alaska.
14
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Figure 8. Cross drainage by outsloping. Slight rillinq shows that, the outslope gradient is more than
is needed. However, no sediment was transported beyond the road clearing. Near Fairbanks,
Alaska.
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*%£'•£.••'••*-" '• - --.."• 5 "• ~-
kv^-' L.;.i', - ---• ft
%-~-- - - ~^$^'"' '^0^
Jr.- •-^f'^^^^^^'^ifr^-
Figure 9. This rilling of an outsloped reach was due to water accumulation
could be of less gradient; more cross drainage would prevent the
Alaska.
from above. The outslope
rilling. Near Fairbanks,
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Figure 10. Good cross drainage by outsloping a gravel road surface. Near Fairbanks, Alaska
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SMALL LOGS A'NO
SfL/SH HIHO#OHf
/IT TOC Of f/LL
GOOD
OH /WX ROAD
Figure 11.
A cross-sectional design for low gradient logging
roads. (From Packer and Christensen, p. 37)
Figure 12. An old forest maintenance road that was built on the "fall line"
in highly erodible soil. Erosion is minor, however, because a
drainage structure upslope prevented the accumulation of water
on the road surface. Bonanza Creek Experimental Forest, near
Fairbanks, Alaska.
18
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Figure 13. This view of a road drainage shows a diversion accomplished upslope from the road section
shown in Figure 12. This diversion leads water into the adjacent forest. On this road
such diversions were installed some years after the road was built. This water control
has greatly reduced road erosion.
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4. Cross streams at right angles and install culverts on the natural
gradient of the stream. Adjustments of road alignment may permit
crossing a stream at a reach with less gradient.
5. When crossing permafrost areas is unavoidable, design to preserve
the permafrost. One acceptable design is to place fill material
directly on the undisturbed vegetation layer using endhaul tech-
niques. Vehicular traffic should be kept off permafrost areas
except on established roadways.
6. On valley bottoms, crown roads for proper drainage.
7. Road location and design plans should be approved by the appropriate
agency before construction commences.
SPUR ROADS
Locate spur roads to take advantage of stable soils and where possible
stay on the topographic contour. Design spur roads with the same
objectives as those for main haul road. Design roads leading away
from landings in such a way as to prevent accumulated water at landings
from entering the roads. Design spurs, such as logging skidtrails, to
give a systematic network, not a random one. Planning and designing for
systematic spurs results in fewer trails with less mileage. Plan
the spur roads within the total management plan. Be prepared to take
measures to prevent erosion (Figure 14). Design skidtrails to avoid
crossing ravines; skid from both sides to reduce erosion. Figures 15
and 16 compare two skidtrails, one of which is eroding.
DRAINAGE
Proper drainage is without doubt the most important single factor to
consider in designing and building small access roads; yet it is often
neglected, as Figures 17 and 18 clearly show. Design of structures
for proper drainage is controlled primarily by topography and the
nature and quantity of precipitation; also important are soil proper-
ties and forest floor materials.
1. Install culverts on the same gradient as the drainage profile,
and, if the stream is perennial and contains fish, select a reach
with low gradient. Figure 19 shows an improperly installed culvert
that failed. In such situations, a broad gravel ford might be a
better crossing method.
2. Use culverts large enough to carry snowmelt runoff; this is fre-
quently the season of maximum drainage. Avoid small-diameter,
culverts, because they clog easily with debris or ice and are
ihen useless as drainage structures. '
3. Protect intakes and outlets of culverts from erosion by riprap
or other suitable methods where needed (Figure 20).
20
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SKID TRAIL EKOSION CONTROL DEVICES
©
DIG TeENCH WITH MA TTOCK.
AT 5L/GtfTAXGLE
TO T£A/L DEIPEE/
THAN BOTTOM r>
OF sff/o re AIL '
PLACE STAKES
SOCKS ov
MLL 5/DC TO HOLD
LOG M Te£NCH PXOWDE
Figure 14. This series of
diagrams portrays a sequence
of operations during the
installation of erosion con-
trol devices on skid trails.
Such devices will not be
effective on permafrost areas
because thermal erosion is not
controlled (another reason for
avoiding permafrost where
possible). (From Haussman
1960, p. 38)
AT LOG LANDINGS''
PLACE 6m POLES ACROSS •-
LAMXMGS WITH STAKES TO
VOLQ. SPREAD LEAVES, WEEDS.
HA Y 0/e /*jlA/(/££ ACROSS 1 ANDtNG.
Figure 15. Skid trail over which whole trees were skidded from the clear-
cut in the background. Skidding unlimbed logs does not appear
to disturb the surface of the forest floor as much as does
trimmed logs. This skid trail still had a sufficient organic
mat that should prevent erosion because no water will be con-
centrated from upslope to induct erosion.
21
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Figure 16. Erosion of a skid trail from an earlier logging operation where
silty soil was exposed and no drainage was provided. Erosion here
can still be controlled by drainage but may become serious if
control is not initiated.
22
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r\j
OJ
Figure 17. An example of Improper design for a residential access road running nearly on the fall
No drainage structures were put in, with the results shown here. Off Goldstrtvim Road.
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Figure 18. Deep gully in a
powerline access road, caused
by improper drainage. The
arrow points to a man standing
in a 5- to 6-ft. deep reach.
Figure 19. An improperly installed culvert that not only plugged wit.i ice,
but was undermined by water accumulated above the fill. This
drainage is probably a perennial stream and a bridge or a broad
gravel ford appear to be better solutions to this situation.
24
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Figure 20, A & B.
These diagrams illustrate devices designed to prevent
erosion on deep fills. (From Packer and Christensen,
p. 40)
4. For streams containing fish, use culvert designs (Figure 21)
approved by fishery biologists to permit passage of fish (Metsker
1970, Woodworth 1967).
5. Approach all crossings at right angles if at all possible.
6. Consider bridging as an alternative if proper culvert design
results in too high a cost. When bridges are required, consult
with the land management agency engineers for recommended struc-
tures to fit the conditions, loads, and materials.
7. Use open-top culverts (Figure 22), spaced to prevent accumulations
of drainage water, between natural drainages. Protect the area
receiving outflow from these culverts by some method to prevent
erosion and to spread the water over enough area to allow it to
enter the undisturbed forest floor without erosion. Haussman (1960)
gives some recommendations for spacing and installing these cul-
verts, although modifications may be required for subarctic
conditions.
8. Install culverts near main dralnageways to intercept any water
that might enter the stream near the main culvert or bridge
25
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Center of Gnbion
Depressed or
NoU-hed
Figure 21, A-E. This series of diagrams shows several methods of cul-
vert installation; some are satisfactory, others act
as barriers to migratory fish, (from Metsker 1970,
pp. 5-7, 9, 14) A, Protection of downstream channel
bottom is often required. Sectional view showing back-
flood pool and gabion. B, Fish passage may be provided
in streams that experience wide ranges of flowing by,
providing culverts at different elevations. C, Dia-
grammatic view showing fish in the slack water area.
D, Diagrammatic sectional view demonstrating the diffi-
cult, or often impossible, jump facing the migrating
fish. E, Diagrammatic sectional view of deep plunge
pool.
26
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BOX CULVERT
.Grovel fill
7 Wo«h«r
NOTE'. All culvwtl should fall
not lest than !/• to th« foot
-^ 'RIPRAP OF STONE
Figure 22.
These diagrams show two open-top culvert designs with
suggested dimensions and recommended procedures for
installations. (From Haussman 1960, p. 1 and 9)
(Figure 17A); divert this water from the stream bank or protect
the outlet.
EROSION CONTROL
Proper location and design of roads will reduce erosion, but some
portions of the system may require special measures. Figure 23 diagrams
two ways to prevent" road erosion without installing culverts.
CONS7RUCTCO
CffOSS DBA IN
Figure 23. Two construction techniques that effectively prevent accumu-
lation of runoff without the need for additional materials
such as culverts or bridges. A, rolled grade, and B, con-
structed cross drain. (Packer and Christensen, p. 34)
27
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Figure 24 illustrates some of the factors that control spread of sediment
or erosion of road surfaces and some methods for controlling these
factors. Slash from the right-of-way clearing piled on the lower edge
of fresh fills will intercept and spread sediments until new vegetation
is established (Figures 25, 26, 27, and 28). Three effective attempts
and one failure to prevent erosion are shown in Figures 25-28. In
logging operations where skidding down slopes is required, structures
should be designed to divert runoff from the skidtrail to the undisturbed
forest litter layer. Kidd (1963) gives some recommendations to reduce
erosion from skidtrails. Use logging debris to control erosion along
abandoned skidtrails as the logging operation proceeds.
Protect areas below open-top culverts from erosion by placing rock
basins or logging debris to dissipate the energy of the falling
runoff water (Figures 20 and 22).
When flowing streams are to be bridged in winter with ice bridges,
avoid high banks that would require deep cutting for the approach
(Figure 29).
28
-------
s«
*r.
M/ODLC TQPOOIWPHIC
POSlTiCN
/ /NCH
ff'tt OtPTH
SOUTH FACtNS 4
Figure 24. These diagrams illustrate some factors that control the spread of
sediment and erosion of road surfaces and some measures that may
retard sedimentation of nearby streams: A. Factors that affect
distance sediment moves downslope; B. Sediment movement downslope
from a road cross drain; C. Factors affecting erosion of road sur-
face; D. Rill erosion on a road surface below a cross drain. (From
Packer and Christensen, pp. 8, 3, 6, and 2, respectively)
29
-------
CO
o
_
Figure 25. A good example of debris on the toe of a fill slope that acts as a sediment trap,
-------
•-"..-.
*^;-* :' .>•: '
N**
Hli
Figure 2f,. Logging debris can effectively protect cut slopes if the cut is not too
-------
00
no
Figure 27. An example where debris from road clearing was not utilized as erosion control material. In
this instance, no forethought was given to erosion control of fill slopes during road con-
struction, and debris was moved too far downslope to be of value in erosion control.
-------
CO
CO
figure ?8. The forest floor vegetation mat is an effective erosion control agent for cuts
Stumps on the edge of the cuts are an important part of this mat and should he
unless they actively interfere with the hauling operation.
if not disturbed,
left in place
-------
-.
Figure 29. An ice bridge across the Chena River with a proper approach made without extensive bank
cutting. The water under the pickup was about 8 feet deep during the summer.
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CONSTRUCTION
It 1s during the actual construction process that most environmental
damage is likely to occur. All the proper safeguards designed into
the plan are useless unless the operator follows a good operation
procedure. Contracts should include provisions for temporary sedi-
ment control while construction is under way. Costs for this control
are to be included in the total estimate, just as other construction
costs. When interim measures to prevent erosion during the construc-
tion period are neglected, considerable sedimentation can result.
High quality road construction should be insisted upon by the land
owner or his representative. Regular inspections should be made
during construction by a qualified official with authority to assure
that road construction meets design requirements.
Before construction starts, preferably after the planning document
has been approved, conferences between the equipment operators and
the resource manager should be held. If the operators are made aware
of the need for environmental protection, and are actively partici-
pating in it, detailed inspections may not be so necessary. Unless
the operator, his crew, and the resource manager enter into the spirit
of environmental protection, no amount of inspection can prevent damage.
The ultimate objective is to motivate each person concerned so that his
efforts to protect the environment will result in a. better place to
live.
SURVEYING AND RIGHT-OF-WAY CLEARING
1. Before and during construction activities, the operator should be
briefed on particular environmental problem areas by appropriate
specialists. These briefings should include fire prevention and
suppression training for all personnel.
2. During establishment of center!ine, grades, and boundaries, equip-
ment should be kept on the right-of-way whenever possible. Utili-
zation of equipment off established routes leads to erosion and
uncontrolled permafrost melting.
3. All timber should be cut close to the ground to preclude unsightly
stumps remaining after completion of the project. Timber should
be felled into the right-of-way and away from water courses.
Standing timber should not be cleared by bulldozing. The results
of such a practice are unsightly and can be a fire and insect
hazard (compare Figures 30 and 31). Clearing width should be
kept to the minimum required for the right-of-way in order to
maintain esthetic values. Contrasting clearing widths are com-
pared in Figures 32 and 33. Figure 32 shows an ample width.
4. The organic mat should be preserved where the design calls for
overlay. This procedure is the most effective method to control
permafrost melting.
35
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CO
cr>
Figure 30. Proper right-of-way clearing. Slash disposal was probably by burning; it could also be handled
by chipping. If the subgrade is muskeg, permafrost, or poorly drained, the slash could be hand
placed as a mat under the fill.
-------
CO
—I
T~ <¥ &£.$
.
. >
Figure 31. Clearing by bulldozer leaves berm piles such as these. New Minto Road, 1973.
-------
Vf%
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OJ
00
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0— a
,- ,; / '** M*^' *
*"~^ *:**! ,. &'•• ' .--,'ir-
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Figure 32. Completed clearing for a forest haul road before hauling had commenced. Although this clearing
removed a minimum number of trees, it is amply wide to accomodate trucks hauling 80-ft. logs.
Such a road is recommended to prevent erosion, as a minimum amount of the forest is disturbed.
-------
Figure 33. Another portion of the haul road shown in
view illustrates excessive clearing for a
hauling; this cleared zone is about twice
factory otherwise.
Figure 32 that was built the previous summer. This
haul road to achieve the limited objective of log
as wide as necessary for such a road, but is satis-
-------
5. Logs should not be skidded or yarded across any stream without
prior approval and log landings should not be located on the banks
of any live stream. Where use of heavy equipment would be detri-
mental to existing conditions, hand clearing operations should be
used (Burns 1972).
6. All debris from clearing operations should be disposed of by
windrowing at the toe of the fill to act as sediment traps (Figures
11 and 25).
EARTHWORK
1. Where the road design calls for full bench construction, the full
cut is made, excess excavation is end-hauled from the cut, and it
is deposited in stable locations well above high-water levels.
Waste materials should not be deposited directly into stream
channels. Where necessary, all fill should be compacted to reduce
the entry of water and to prevent the fill material from settling.
2. Construction-area drainage should be collected and kept out of
streams. Seepage pits or other confinement measures can be used
to prevent diesel oil, fuel oil, or other liquids from running
into streams. Use drip collectors on oil -transporting vehicles.
3. Soil disturbances can be kept to a minimum by constructing roads
only when soil moisture conditions are favorable. New roads should
be rough graded only as far as can be completely finished during
the current season. Ditches and drainage installations should be
finished on the section being worked on before another section is
opened up or before shutting down for the season. Figure 34 shows
a new logging road that was stable during the fall and winter,
but eroded during breakup before construction was completed.
Figure 27 shows similar results on bar ditches running straight
the slope on a small residential development near Fairbanks.
4. Each graded section should be fully backs! oped, except where
vertical cut banks are more stable than sloping ones. In critical
slump areas, large cuts should be graded to slopes of not more
than 2 to 1 and horizontal drain pipes used. Also, all large
fill areas should be protected with surface drainage diversion
systems. Culverts should be placed to cause the minimum possible
channel disturbance and fill materials kept away from culvert
inlets and outlets. During road construction, earth moving
activities should not be permitted when the soils are saturated.
Road machines are allowed to work in streambeds only for laying
-culverts or constructing bridge abutments, and then only in the
absence of spawning fish. Streamflow should be diverted from( ;
the construction site whenever possible to prevent or reduce
turbidity.
5. Drainageways should be clear of all woody debris generated during
road clearing or construction. Clearing debris should be windrowed
40
-------
K) "S x
: '•' v
•» x*-
d
^
Figure 34. Erosion caused by melt water from spring breakup (1972); some of those gullies are 3-4 feet deep
and could have been prevented if drainage had been provided the previous season in anticipation
of just such a situation as this.
-------
outside the road prism, except where burning of the debris is
necessary to reduce fire hazard, prevent insect Infestations, or
to improve esthetics.
6. All vegetal mat possible should be left on the edge of the cut.
This mat is effective in protecting the cut and improves stability
during breakup.
7. Upland materials and existing material sites should be utilized
in place of clearwater stream materials if additional road
materials are required.
8. Installation of culverts on fish streams should be at low gradient
with the bottom of the outlet below the natural streambed to
prevent erosion at the downstream end of the culvert.
9. When necessary, because of outfall erosion, an approved stilling
basin should be constructed at the downstream end of the culvert.
Stabilize the pool sides with riprap or other appropriate material
to prevent erosion.
10. Water may be diverted around the work area in the streambed during
the installation of the culvert to reduce sedimentation, but only
when the diversion would not affect fish passage or spawning. A
conduit may be needed to avoid erosion.
11. Water diversion ditches or pumps should be screened with an approved
device to prevent harm to migrating fish.
12. Abandoned water diversion structures should be removed, if at
all possible, or be plugged and stabilized to prevent trapping
fish or impeding fish passage.
13. Erosion control structures, such as water bars, contour furrows,
water spreaders, diversion ditches, or gully plugs, should be
constructed to avoid induced and accelerated erosion and to lessen
the possibility of forming new drainage channels. Control measures
should be designed and constructed to minimize disturbance to the
thermal equilibrium, thus reducing the adverse effects of perma-
frost degradation.
14. Unless otherwise approved, temporary access over streambeds
should be made through use of fill ramps made of coarse materials,
rather than by excavating through stream banks. Such ramps should
be removed upon termination of seasonal use or abandonment.
SUPPORT ACTIVITIES
1. The operator should assure that all persons take appropriate
measures for the prevention and suppression of fires on right-of-
way areas and other lands, and comply with all applicable laws and
42
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regulations and with instructions and directions concerning the
prevention and suppression of fires.
2. Area-wide pest control should not be attempted; such action fre-
quently leads to ecological unbalance. Pesticides and herbicides
are limited to nonpersistent (such as parathion, malathion, or
pyrethrum) and immobile types. When pesticides are used, only
those from an approved list should be applied, and then according
to Federal, State, and local regulations.
3. Camp wastes of all kinds should be disposed of by approved methods.
Effluents from treatment systems should not pollute receiving waters.
4. Petroleum wastes should not be disposed of so that they damage the
environment or enter a body of water; these wastes include oil
changes, spilled fuel, and antifreeze.
5. Mobile ground equipment should be kept out of water courses, except
for crossings within the right-of-way, and then only in a manner
that minimizes disturbances.
RESTORATION
1. All slopes should be left in a stable condition.
2. Haul ramps, berms, dikes, and other earthen structures should be
leveled unless otherwise directed by the resource manager.
3. Connect material pits in stream and river bottoms and channels
to the stream by channels constructed to allow flow of water through
the pit, if approved by a fisheries biologist.
4. Vegetation, overburden, and other materials removed from surfaces
of borrow and waste sites should be disposed of in an approved
manner at termination of use of the site. Chipped vegetative debris
can be spread evenly over these sites, together with other organic
materials and topsoil. If possible, during construction or
immediately following terminal use of the site, the area should
be revegetated. A vegetative guide was recently published by the
Soil Conservation Service (1972) that recommends seed mixtures
for the major climatic zones and soils of Alaska. Seeding on the
snow is one procedure that should be considered and used, if feasible,
to take advantage of early moisture for seed germination.
5. Upon abandonment or relocation of a campsite, the area should be
cleaned up and restored to a condition satisfactory to the regula-
tory agency.
6. All disturbed.areas should be left in a stabilized condition.
Stabilization practices may include seeding, planting, mulching,
and the placement of mat binders, soil binders, rock or gravel
blankets, or structures, as determined by the conditions at the
site. Figures 35 and 36 show two stabilization practices.
43
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*-• w-S$7£*S^^~r~ •
Sr£}*»^ .•••'-•••.•"" '.. .v -
•' •-' .;-;\,: -":-." -:-/•; -• .^V""'
' '' ' .:•• •,-;; . -----
SS?
Figure 35. Seeding to stabilize cuts in silty soil. Mote the native vegetation overhanging the cut.
Road machinery was kept off the right-of-way above the cut, which further tends to stabilize
these slopes. Gold Stream Road, 1973.
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f*£3N&fe?a&£
Figure 36. Rock armor in roadside ditches effectively prevents erosion on erodible silt. Note here the
sharp line between the rock and the grass-covered silt of the cut; such treatment can be
emplaced with road machinery and requires little maintenance. (Gold Stream Road north of
Fairbanks)
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ROAD MAINTENANCE
Proper maintenance is essential if a road is to remain usable.
Long after construction activity ceases, and as long as the road is
being used, maintenance must continue in an efficient and timely
manner. The accrued maintenance cost may equal or exceed the original
cost of construction. These costs can be reduced if the route is well
selected and the problem areas are properly handled during design.
Permafrost and long, severe winters cause unusuep problems in the
subarctic that add to those of road maintenance encountered in milder
climates. Seepage zones can cause icings that may build up to several
feet if steps are not taken to keep small channels thawed to remove
liquid water and prevent it from freezing on the road surface.
Full and thorough maintenance of all portions of the road system is
necessary to prevent water quality degradation owing to accelerated
erosion during heavy rainstorms. This includes the regular main-
tenance of drainage diversions, such as cleaning culvert inlets before
freezeup and keeping them clean during the rainy season to diminish
the danger of clogging and the possibility of washouts. It also
includes the inspection of revegetation on obliterated spur roads and
reseeding where necessary. As specified above for construction ac-
tivities, all excavated material should be end-hauled and deposited
in safe bench or cove locations well above high-water levels. This
material should nev.er be deposited directly into flowing streams.
Some additional suggestions are:
1. Spur roads that outslope should be cross-drained and berms on
the outside edge removed, except those intentionally constructed
for the protection of road grade fills.
2. Outsloped road drainage can be retained by performing proper main-
tenance grading. This precludes both the undercutting of newly
or partially stabilized cut slopes and the leaving of a berm
(except for fill protection) along the outside edge of the road,
which might concentrate drainage on the road.
3. Extreme caution is necessary in the selection and application of
herbicides for controlling brush encroachment along road edges.
These chemicals should not be allowed to drift or run off into
streams to cause objectionable tastes or odors in the waters or
to create adverse conditions for aquatic life or human consumption.
Mechanical equipment is preferred to herbicides for control of
roadside brush (Figure 37 shows one such unit). ,
' j
4. Maintenance should be planned and scheduled on a continuous basis
for routine work.
46
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DANGER
ATCH OUT FOR
ROTATING BOOM
AND FLYING DEBRIS
Figure 37. Mechanical clearing along roads by shredding without the need
Such a method improves driving visibility and avoids the need
to get into roadside
for herbicides.
di tches,
-------
5. All personnel should be asked to report unusual maintenance needs,
such as a new frost boll or sedimented culvert, before it becomes
a serious problem.
6. Cuts and fills subject to erosion should be stabilized with vege-
tation or other material.
7. Stabilized slopes should not be disturbed by maintenance equipment.
The road should be kept crowned and free of ridges along the edges
to maintain lateral drainage. Material cleared from ditches should
not be moved to where it can wash into water courses.
8. Vertical cuts are usually the most stable slope for wind-deposited
silts. For these cuts, drainage must be provided and maintained
to prevent water from running over the upper edge of the cut banks.
9. On haul roads used in winter, snow berms should be removed before
breakup to permit lateral drainage and prevent concentrating water
between berms and running down center!ines.
48
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PUTTING ROADS TO BED
The overall management plan for resource development in a particular
area determines whether or not roads will be maintained or abandoned
(put to bed) CFigure 38). On logging areas, for example, most of the
main haul and all spur and skid roads usually will be abandoned and
allowed to revert to native vegetation. If roads are put to bed,
it may be years before they are again used. A well-planned, properly
constructed road system can be cheaply put back into use if certain
measures are taken in putting the roads to bed. Because of the long
time between abandonment and re-use, many natural materials may rot
and be useless when again needed. Therefore, structures using these
materials should be removed. Since active erosion prevention measures
will no longer be available, utmost care must be taken at this time to
provide proper, well-protected drainage and establishment of vegetation
on all disturbed areas.
GUIDELINES FOR PUTTING ROADS TO BED
1. All open-top culverts should be removed and sufficient cross-road
drainages provided to accomodate runoff at breakup. Culverts
placed in natural drainages should also be removed, as their inlets
collect debris and gradually plug, resulting in washouts over the
road. These drainages can be stabilized with gravel, and native
vegetation allowed to establish. Native tree species are quickly
re-established, even on old compacted roads, once traffic is elimi-
nated (Figure 39).
2. For several years after abandonment, the road should be inspected
immediately after breakup for evidence of erosion. Eroded portions
should be repaired immediately to prevent further erosion and sedi-
mentation.
3. Disturbed, bare areas should be seeded with recommended grass
species and fertilized with NPK mixture to insure initial quick
growth to protect bare soil (Soil Conservation Service 1972).
4. Petroleum products, containers, and abandoned equipment should be
removed from landings, service areas, and roadsides before the
roads are put to bed.
5. On old haul roads and main skidtrails, special attention should
be paid to cross draining at points just above steep sections
and to the credibility of the soil.
6. Vegetative debris is usable to stabilize sections likely to erode
after abandonment. Haupt (1959) gives some good recommendations
on spacing of drainages when putting roads to bed, and Kidd (1963)
does the same for skidtrails.
49
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on
O
Figure 38.
An area on the Chena River logged by selective cutting. Several haul roads and yarding areas appear
in this photo that will probably be "put to bed" and allowed to return to forest. This level terrain
should not develop problem areas caused by erosion or thawing; no permafrost is present here.
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Figure 39. Abandoned roads soon become revegetated even though they were gravel and thoroughly compacted. This
photo shows an abandoned portion of the old Steese Highway about a mile west of Cleary Summit, abandoned
1n 1964. The brush shown here is alder, which appears to be the initial invader of abandoned roads
(spring 1973).
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ROADS ON MUSKEGS
INTRODUCTION
Muskeg is an organic terrain consisting of living vegetation over
peat or plant detritus of any depth 'over a mineral sublayer. Muskeg
is similar to bog, except that the latter is confined to smaller area
units.
Many properties of muskeg make customary road designs of limited appli-
cability and must be considered when developing access across these
areas. Such properties include vegetation cover, peat depth, type of
mineral sublayer, peat structure, peat density, shear strength, peat
water content, drainage pattern, permeability, frequency of open water,
permafrost, etc. (MacFarlane 1969).
The problems with construction over muskeg are many and may represent
severe environmental disturbances. Muskeg, like permafrost, should
be avoided wherever possible. This sometimes can be done by adequate
planning through on-the-ground exploration and study of aerial photo-
graphs. Where muskeg crossing is unavoidable, great care should be
taken to construct stable roads compatible with the engineering charac-
teristics of muskeg.
MUSKEG PROPERTIES
On muskeg, the vegetation cover can vary from trees through shrubs,
herbs, grasses and sedges, mosses and lichens. Depths may range from
2 or 3 inches to over 80 feet. Structure is a function of the vege-
tation type that built up the peat; it may range from coarse and
fibrous to fine and smooth. The density of saturated peat is about
the same as the density of water, with higher densities usually associated
with higher inorganic content. Drainage patterns can indicate subsurface
topography and the extent to which the muskeg is confined. Open water
usually indicates places that must be filled or bridged. Permeability
varies widely, but many peat types are relatively impermeable. Construc-
tion over frozen muskeg is a special problem and largely one of main-
taining thermal stability.
The significance of physical properties in road construction is developed
in considerable detail by MacFarlane (1969). Because such detail is
beyond the scope of this paper, only some general' principles in develop-
ment road construction over muskeg will be considered.
ROAD CONSTRUCTION
Carbon dating indicates that the oldest known roads in muskeg were
built between 4,000 and 4,800 years ago. These were corduroy road-
ways of planks tied together (MacFarlane 1969). This method of
construction is still used today, usually with a soil fill for a
smooth surface.
52
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The method of road construction selected depends upon the frequency
and weight of traffic. For some purposes, considerable settlement,
undulation, and distortion of the roadway can be tolerated. For such
low standard roads, the availability and cost of materials such as
corduroy, sawdust, gravel, etc., will determine the type of construction.
The most inexpensive method of constructing roads on muskeg and at
the same time creating the least environmental disturbance is
to float the road directly on top of the vegetation mat if the muskeg
is less than about a meter in depth. If the peat exceeds a yard in
depth, a corduroy is used over the vegetation mat before laying the
road fill.
Right-of-way clearing should be done by hand in order to keep equip-
ment traffic off the muskeg surface. All woody vegetation should
be cut off at ground level with the cut material placed as a mat on
the surface. Under no circumstances should the surface mat of the
muskeg be disturbed (MacFarlane 1969).The fill, preferably sand
and gravel, may be placed alone over shallow peat, or over corduroy,
brush, sawdust, wire mesh, straw bundles, or dried peat (MacFarlane
1969).
Corduroy is laid with longitudinal stringers, with staggered joints,
across which are spiked decking logs. Branches and smaller trees
are placed on top of the logs.
Another type of construction is laying the cleared trees side by side
(without linking) across the centerline of the road. Small trees and
brush make up the next course. In both cases, the mat should be com-
pletely covered by fill so that air is excluded. If air is excluded,
the mat should remain sound indefinitely (MacFarlane 1969).
Dralnageways should not be constructed if drainage can be avoided. If
drainage is necessary, it should be planned to create the least possible
disturbance to the natural drainage pattern. Lowering the water table
will cause deterioration in the structural strength of the natural
muskeg mat (MacFarlane 1969).
Embankment of fill should be granular and can be larger than four
inches for the base course and up to 3/4 inch for its top course. In
southeast Alaska, for heavy loads, logging spurs in muskeg are built
up of coarse rock over a corduroy and topped with a surfacing course
of finer material. The fill, or embankment, may need to be from 1 1/2
to several feet thick, according to traffic demands.
In frozen muskeg or permafrost areas, the road design is based on pre-
serving the frozen state (MacFarlane 1969). Right-of-way clearing
should barely precede the fill, and the fill should be up to 6 feet
thick to maintain the permafrost.
53
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Perhaps the simplest way to deal with muskegs is to use light-duty,
winter haul roads. Vegetation is cleared to prepare a surface that
is easily leveled once freezing has started. Hand clearing
creates the least disturbance to the surface mat. However, dozing
is sometimes done after freeze-up and in the season before the road
will be used. Harrison (1955} reported that the uneven surface will
partially "settle down" during the summer. The greatest depth of
freezing is obtained by removing or packing the snow cover. It has
been reported (Harrison 1955) that even snowshoeing is helpful, followed
by snowmobiles packing until the freeze depth is enough to support
heavier equipment for smoothing the road surface.
54
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ICE BRIDGES
During winter operations in valley bottoms, it is frequently necessary
to cross over the stream ice which, to be reliable, should be streng-
thened by ice bridging. Ice 4 to 6 feet thick will support heavy
loads that continue to move, but tends to deform and crack under
static loads. Army tanks crossed the Imkin River in Korea on a total
ice thickness of only 20 inches with timber pads under the tracks,
so it is apparent that ice freshly frozen is amply strong to carry
moving loads.
Although many ice bridges include timber, limbs, and other materials,
there is another philosophy which reasons that proper construction
of an ice bridge without extraneous materials gives adequate strength.
It is generally agreed that the ice at crossings must be strengthened
by building up natural 1ce in broad, thin layers. Some say that
additional materials only add to the total work and cost and do not
contribute additional strength. Prior to pumping water over the ice
to freeze, all snow should be removed from the crossing, which permits
thicker ice naturally because of the absence of insulating snow.
In building the 1,500-ft. ice bridges across the Yukon River in the
winter of 1969-1970, a part of the Hickel Highway, the Alaska
State Highway Department used logs as reinforcing material before
pumping water to thicken the ice. Prior to laying the log materials,
snow was bulldozed into berms parallel to the road to expose clear
ice. This permitted deeper freezing and also helped to contain water
that was pumped onto the road to thicken the ice containing the
reinforcing log network. Water was added in thin layers to prevent
cavities that form if thick layers are pumped into place. The
final ice thickness was 5 feet. Instead of raising the roadway as
the ice thickness increased, the added ice thickness "flowed" downward
and the roadway was level with the nearby thinner ice that had formed
naturally. After the Yukon ice bridge was completed, the river stage
dropped almost 5 feet, yet the bridge remained solid and supported loads
as high as 100 tons on a single truck, semi-trailer unit. It is thought
that the reinforcing timber contained in this bridge did in fact pre-
vent its failure when the water level dropped.
i
Because a relatively large quantity of timber was used on the Yukon,
it was thought that, at breakup, this mass of floating timber would
cause jams downstream. However, most of the bridge melted before
breakup, releasing the timber, which gradually floated away above
the ice, and no jams were caused. Figures 40, 41, and 42 show the
Yukon ice bridge at various stages of construction and clearly demon-
strate that a large volume of timber went into its structure.
The ice bridge built across the Yukon in 1973-74 used ice built up in
thin layers, without reinforcing timber. If the water is pumped in
thin increments, there is no need to confine it, because it freezes
55
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01
en
*
Figure 40. Yukon River ice bridge site (1969) in the early stages of construction. Timber from the nearby
forest is being brought in by snow machine and a narrow strip across the river has been bladed
free of snow. This strip was later widened with a small bulldozer into berms parallel to the
road. Stripping off the snow permits thicker ice to form. (Photos in Figures 40-42 courtesy
of Fairbanks Daily News-Miner)
-------
en
*• %•. v/^ c
-5 . •/' •* ^
V •*< i •'
-------
en
CO
Figure 42. Pumping water from under the ice in
All timbers were solidly cemented
j_ -I _ . . — J .£".__. rrtO ~7 rt O L. d-. *
thin increments to give a total ice thickness of 5 feet
n,. UII..UC.;, »c,c *v,,v,j ^,,^,,^^ in place as the water froze. Temperatures during these
operations ranged from 50°-70° below zern.
-------
rapidly during cold weather. What is desired is a broad expanse of
thickened ice whose cross-section is similar to a convex lens. Hughes
(I960) cites some experiences using outboard motors as pumps to thicken
ice in Canada that should apply equally well for Alaska. Not using
extraneous materials in the bridge avoids the introduction of debris
when the bridge melts during spring breakup.
Whether or not reinforcing material is used, several suggestions are
offered for the construction of ice bridges. Snow should be removed
from the roadway, allowing quicker, deeper freezing. If the ice thick-
ness is increased by pumping water, water should be added in thin layers
to prevent formation of cavities, which weaken the ice. An un-reinforced
bridge should not be used if the water is not in contact with the ice.
Heavy loads should not be allowed to remain stationary on an ice bridge;
Breakage of ice has been experienced under parked planes. If the load
continues to move, the ice supported by water does not deform and will
continue to support the load.
59
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REFERENCES
1. Burns, J. W. Some Effects of Logging and Associated Road
Construction on Northern California Streams. Transactions
of American Fisheries Society. 1_01_:1-17. 1972.
The research reported here, although done in California, clearly
demonstrates that most damage is caused by logging road con-
struction and can be materially reduced by employing recommended
procedures during road construction and skid road layout.
2. Federal Water Pollution Control Administration (FWPCA).
Industrial Waste Guide on Logging Practices. Portland,
Oregon. 79 p. February 1970.
Although this guide deals with forests of the Northwest,
many recommendations apply equally well to Alaska.
3. Forest Service. A Research and Development Program for
Advanced Logging Systems (FALCON). U. S. Department of
Agriculture, Forest Service. 1972.
This pamphlet is included to indicate some new trends in
Forestry, Advanced Logging and CONservation and considers
such innovations as balloon and helicopter logging, among others.
4. Harrison, W. C. Primary and Secondary Access over Muskeg in
Forestry Practice. Proceedings of the Western Muskeg Resource
Meeting. National Research Council of Canada, Technical Memor-
andum No. 38, p. 6-13. 1955.
5. Haupt, H. F. A Method for Controlling Sediment from Logging
Roads. USDA Forest Service Miscellaneous Publication No. 22.
22 p. 1959.
Engineering and other technical data are presented that should
be helpful to any operator planning logging roads.
6. Haussman, R. F. Permanent Logging Roads for Better Woodlot
Management. USDA Forest Service, Northeast Region, Division
of State and Private Forestry. 1960.
Although directed at small operations far from Alaska, this
bulletin contains many sound recommendations on design and
construction that are useful everywhere.
60
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7. Hughes, J. R. The Outboard Motor—the New Ice-Making Machine.
Canadian Pulp & Paper Association, Woodlands Section, Index No.
1949 CB-10), p. 1-5. 1949.
Hughes describes the use of small outboard motors (10 hp) as
efficient means of pumping and spreading large volumes of water
to thicken ice and provide sufficient strength to support heavy
loads.
8. Hutchison, 0. K. Alaska's Forest Resource. USDA Forest Service
Resource Bulletin PNW-19. 74 p. 1968.
The most accurate and up-to-date appraisal of forest resources of
Alaska. Interior forests are well covered.
9. Kay, A. R. and Lewis, R. B. Passage of Anadromous Fish through
Highway Drainage Structures. State of California, Division of
Highways, Highway Research Report No. 629110. June 1970.
Concludes that properly built drainage structures do not interfere
with fish passage, presents technical data for design.
10. Kidd, W. J., Jr. Soil Erosion Control Structures on Skidtrails.
USDA Forest Service Research Paper INT-1. 8 p. 1963.
Presents many design considerations on controlling sediments
derived from skidtrails; most recommendations are applicable
in Alaska.
11. Lantz, R. L. Guidelines for Stream Protection in Logging Operations.
Oregon State Game Commission, Report of Research Division. 1971.
This excellent report not only presents a good set of guidelines
to protect streams, but also gives a brief description of prin-
ciples and rationale of biological needs for protection; based
on research done recently in western Oregon but applicable in
Alaska.
12. Lotspeich, F. B. Environmental Guidelines for Road Construction
in Alaska. Environmental Protection Agency, Alaska Water
Laboratory, College, Ak. Report No. 1610-Fol, 127 p. August
1971.
Presents the environmental need for controlling sedimentation
during road building, how National Environmental Policy Act is
influencing new concepts, and offers recommendations for protec-
tion during the road building cycles. Includes photos illus-
trating good and bad examples.
13. MacFarlane, I. C. Muskeg Engineering Handbook. Division of
Building Research,-National Research Council of Canada, Canadian
Building Series No. 3. University of Toronto Press. 297 p. 1969.
61
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14. Metsker, H. E. Fish Versus Culverts: Some Considerations for
Resource Managers. USDA Forest Service Engineering Technical
Report ETR-7700-5. July 1970.
Gives a good review of biological requirements for well func-
tioning culverts and why certain conditions must be fulfilled
if fish are to pass through culverts.
15. Murchison, H. G. Preliminary Studies of An Air-Cushion Vehicle
for Logging in Eastern Canada. In Proceedings of 14th Muskeg
Research Conference. May 1971.
The vehicle described in this paper is an example innovation
to harvest trees in areas of boggy ground and permafrost without
disturbance; such a vehicle could well be used in Alaska, where
logging must be done where it is essential to cross permafrost
areas in summer.
16. Packer, P. E. and Christensen, G. F. Guides for Controlling
Sediment from Secondary Logging Roads. USDA Forest Service,
Intermountain Forest and Range Experiment Station, [n.d.]
This pocket-size guide is packed with useful information that
can be carried in the field by anyone involved with logging
roads and summarizes the results of extensive research on
sediment control.
17. Pearce, J. K. Forest Engineering Handbook. U. S. Department of
the Interior, Bureau of Land Management, Oregon State Office.
June 1961.
This handbook was prepared under a contract with BLM and contains
a wealth of engineering information on all phases of logging in
the Pacific Northwest. Many principles are just as applicable to
the Alaskan scene with suitable modifications for environmental
differences.
18. Soil Conservation Service. A Vegetative Guide for Alaska.
Report No. M7-N-22612. 50 p. 1972.
19. U. S. Army Corps of Engineers. Environmental Protection
Measures for Construction Operations. Seattle, Wa. March
1971.
This pamphlet presents protective measures through line
drawings directed at the individual equipment operators,
showing how each can contribute to environmental protection.
62
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20. Woodworth, J. R. Statement of Policy Concerning Facilities
at Culvert Installations. State of Idaho, Idaho pish and
Game Department. August 1967.
This brief policy statement makes specific recommendations for
culvert installation to fit Idaho conditions, many of which are
similar to those of interior Alaska, with the aim of protecting
the fisheries.
63
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1
Accession Number
2
Subject Field & Group
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
I Organization
U.S. ENVIRONMENTAL PROTECTION AGENCY, OFFICE OF RESEARCH AND DEVELOPMENT, NERC-
CORVALLIS, ARCTIC ENVIRONMENTAL RESEARCH LABORATORY, COLLEGE, ALASKA
Title
ENVIRONMENTAL GUIDELINES FOR DEVELOPMENT ROADS IN THE SUBARCTIC
10
Authors)
FREDERICK
AUSTIN E.
B. LOTSPEICH
HELMERS
16
Project Designation
21ARX
2] 1 Note
22
Citation
Environmental Protection Agency report number, EPA-660/3-7^-009, June
23
Descriptors (Starred First)
*permafrost, *thermal erosion, *physical erosion, resource, access road,
environmental protection, water quality
25
Identifiers (Starred first)
*subarctic, *permafrost, *erosion, sedimentation
27
Abstract
This set of guidelines is based on Federal and State regulations that set standards
to protect the total environment. Although major highway construction is under
stringent regulation, pioneer type access roads such as are needed by loggers, miners,
land developers, etc., have been neglected. These smaller roads frequently pose
serious erosion hazards because planning, design, and construction of them is not
thorough, as it is for major roads; this results in erosion, fire and insect traps,
and generally unattractive roadways.
Suggestions and recommendations contained in these guidelines are for the use of
operators with limited engineering and planning staffs. Although all examples
of poor practices are from the vicinity of Fairbanks, all suggested treatments are
taken from the literature from the conterminous United State? with some modifications
for subarctic conditions. "Most of these recommendations are simple in concept, and
if properly applied, do prevent erosion and result in superior access roads which
are esthetically pleasing.
Abstractor
Institution
WR:I02 (REV. JULY I»6B)
YVRSIC
SEND TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. O. C. 20240
* SPO: 19S9-SS9-33S
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