A Guide to
With the implementation of the landmark Forests & Fish Law, Washington’s Forest Practices Rules were
strengthened to require all forest landowners to inventory and schedule needed road work to protect
fish habitat and water quality on 60,000 miles of streams across 9.3 million acres of Washington’s
forests. Thousands of miles of forest roads are used for management operations, as well as recreation
and emergency purposes like fire fighting. These roads serve an important function, and all forest
landowners are required to ensure roads are properly designed, constructed, and maintained, to avoid
negative impacts on forest soils, streams and fish habitat. This informative brochure illustrates the basic
concepts and an array of best management practices for properly constructing, designing, maintaining,
and abandoning forests roads as outlined in Washington’s Forest Practices Rules.
Forest Roads
An Overview of Washington’s
Construction and Maintenance Rules
Erosion Control
Stream Crossings
In locating a road, the forest manager
must take a number of factors into consideration – intended use of the road,
hill slope positioning and slope aspect,
avoiding unstable areas and a good
mix of sunlight and air flow to promote
surface drying.
Road Construction
Grade roads only when necessary to
maintain drainage and surface continuity. This can minimize disturbance of
vegetation that protects soil next to the
side of the road. Install frequent drains,
water bars, or rolling dips for proper
drainage to maintain the road surface.
Design and build roads to
accommodate the desired end use.
For permanent roads, use adequate
drainage and surfacing, shape and
compact the road sub-grade, and use
appropriate ballast.
Protection of exposed soils, vegetation,
mulching, catch basins and frequent
cross drains are all critical to minimizing
road erosion and the delivery of
sediment to streams.
Road Location
by the Washington Forest Protection Association
Road Maintenance
Road Abandonment
When a forest road crosses a stream,
the type and placement of the bridge
or culvert is of critical importance.
The forest manager must consider
such factors as fish migration, aquatic
habitat, water quality, and wetland
characteristics.
For roads that are high maintenance
or present undo environmental
challenges, consider deactivation,
abandonment, permanent closure
or gating. For one-time harvests, a
temporary, one-time road can be
considered.
Drainage
When road runoff is collected in
ditches, drainage structures can help
move the runoff onto the forest floor
while diverting sediment. These
structures such as cross drains and
water bars can minimize erosion of
ditches while reducing the amount of
sediment entering streams.
All forest landowners are responsible for
properly constructing and maintaining
roads to protect fish habitat and water
quality. The state’s Forests & Fish Law
strengthened Washington’s Forest
Practices Rules to require large forest
landowners to submit Road Maintenance
and Abandonment Plans (RMAPs) and
some small forest landowners to submit a
“Checklist RMAP.” Almost 10,000 RMAPs
and checklists have been approved by the
Department of Natural Resources (DNR),
covering more than 59,000 miles of forest
roads. State cost-sharing assistance is
available for small landowners to remove
in-stream barriers through the Family
Forest Fish Passage Program (FFFPP).
Road Maintenance and Abandonment Plans
Landowners are required to inventory roads and
schedule any road work that is needed, generally
focusing on fixing the worst first. Planning and
reporting requirements differ for large and small
landowners. Small forest landowners harvest an
annual average of 2 million board feet or less of
timber. Large landowners must have a DNR-approved
plan in place and complete all road work by July 1,
2016. Small landowners with more than 80 acres,
or individual parcels greater than 20 acres, must
complete an RMAP checklist with each forest practices
application. They are required to carry out the road
work necessary to bring forest roads up to standard.
Small landowners with 20 acre or smaller parcels (80
acres or less in total) have no RMAP requirement,
but are obligated to maintain their forest roads to
minimum rule standards to protect water quality.
Family Forest Fish Passage Program
A cost-share program is available for small forest
landowners with more than two acres. The state will
help defray up to 100 percent of the costs for replacing
barriers to fish passage such as old culverts, log
puncheons, and bridges. More details for this program
can be found at www.dnr.wa.gov/sflo/fffpp.
Road Location and Design
Stream Crossings
Erosion Control
Road Maintenance
Drainage Structures and Landings
Road Construction
Road Abandonment
Goal: To the extent possible, minimize water crossings
and separate forest road systems from streams and other
bodies of water.
Goal: Limit stream crossings and ensure that they meet
fish passage standards for all life stages of fish.
Goal: Control erosion by various means, such as
diverting water off the road, to minimize sediment
delivery to streams.
Goal: Protect fish habitat and water quality, as well as
your investment, by properly maintaining your roads.
Goal: Avoid sediment delivery to streams by controlling
water runoff and diverting it to the forest floor.
Goal: Minimize soil disturbance, so that road
construction activity creates little or no erosion or
sediment delivery to streams.
Goal: To avoid further maintenance, reestablish pre-road
conditions when abandoning forest roads that are no
longer in use.
Road location may have long-term effects on
construction and maintenance costs, safety, and public
resources. A well-located, designed, and constructed
road balances current needs with construction and
future maintenance costs.
Existing culverts in fish habitat streams often restrict
the passage of juvenile fish, and sometimes even block
adult fish movement. They can also increase water
velocity and inlet or outlet drops. The smaller the fish,
the more likely high velocity or drops will prevent
them from moving through the culvert. A general rule
to follow is the closer the installation resembles the
natural stream, the more likely it is to pass
juvenile fish.
When choosing the location for a road, emphasis
must be placed on reducing sediment entering streams
and wetlands. This means limiting water crossings,
choosing routes that can utilize the natural topography
to keep runoff out of streams, and minimizing the risk
of slope collapses or slides.
Best Management Practices
Locate roads to:
•Find optimal water crossings first
•Locate the best landing locations for the logging
operation
•Utilize topographic benches to connect stream
crossings and landings
•Use natural grade breaks to locate drainage structures
•Avoid crossing wetlands including forested wetlands
Avoid or minimize roads in the following locations:
•On side slopes greater than 60 percent
•On unstable slopes and landforms
•In areas with a history of road failures or slides
•Within 200 feet of typed waters or Type A & B
wetlands
•Where seeps or springs are evident
Design roads to:
•Include adequate drainage
•Ensure the sub-grade can support log and rock haul
•Avoid creating sunken roads, which are lower than
the surrounding ground level
•Design road shape (crowned, inslope, outslope)
to support the anticipated haul of timber, rock, or
forest products
In addition to hindering fish passage, any water
crossing represents a possible sedimentation source, so
the best prevention is to limit the number of times a
road crosses streams.
Best Management Practices
When a stream crossing is necessary, the following are
areas to avoid:
•Locations requiring steep road approaches
•Crossing over braided stream channels
•Flat stream gradients immediately downstream of
a steep stream gradient (these are locations where
gravel is deposited making crossings difficult to
maintain)
•Areas requiring deep fills
•Water crossings immediately below unstable slopes
The key to controlling sediment is to control erosion.
Erosion can occur on all parts of the road, but quality
road construction will create a drainage pattern that
minimizes sediment delivery to streams and wetlands.
Many chronic sediment problems can be readily
treated through proper location, maintenance, and
installation of cross drains. Well-placed cross drains
should take water off the road surface quickly, and
direct it onto stable, vegetated ground for filtering and
dissipation.
Other possible means of reducing sediment include
building check dams in ditch lines; installing slash
filter wind rows on fill slopes below the road; installing
a double ditch to carry water over stream crossings;
and placing straw waddles, silt fencing, or logs in road
ditches perpendicular to the slope to slow down
water flow.
Best Management Practices
•Avoid sediment delivery to all streams. Even
the smallest streams carry sediment down to
fish habitat
•Stabilize soils disturbed by construction, especially
near streams crossings
•Cover exposed soils with bio-matting, straw, tree
boughs, or hydro mulching to prevent rain drop
splashing and loosening soils
•Re-vegetate all exposed soils with non-invasive
locally native plants
•Schedule construction only during dry conditions
Timely road maintenance will protect roads and reduce
the risk of impacts to streams and fish. To protect the
sub-grade, grade a road before the surface reaches
severe stages of pothole formation, washboarding, or it
begins to pool water.
During drier months, routine maintenance should
include cleaning of culvert inlets, replacement or
addition of cross drains, adding rock surface where
there is the potential for surface runoff to reach
a stream, and control of roadside vegetation that
interferes with drainage. Then during wetter months,
inspection of roads should occur after large storm
events. In general, road systems that have a higher
level of use require more maintenance, while less-used
roads require less maintenance unless situated in a
high-risk location.
Road Vegetation Maintenance
Good maintenance of roadside vegetation helps
increase visibility, improve safety, and keep roots from
interfering with the roadbed. Management methods
include hand or mechanical brushing and roadside
chemical spraying.
Frequent cross drains or ditch relief culverts on
crowned or in-sloped roads are critical to diverting
water and sediment to the forest floor and away from
streams.
Landings can deliver sediment through run-off water
or through landslides. Minimizing the number of
landings, especially on steep slopes where large fills are
necessary will reduce costs and significantly reduce the
risk to public resources.
Steep slopes or erodible fill material should be
protected at drainage structure outfalls with flumes
to carry the water to a safe location and/or energy
dissipaters such as large rocks or heavy wood material.
Best Management Practices
Drainage structures should be installed in the
following areas:
•As close to the stream as possible
•In the natural drainage area for seeps and springs
•In a location that prevents piracy of water from
one basin to another
•At the bottom of vertical curves
•Where there is evidence of insufficient drainage
Construction techniques are important to providing
adequate resource protection and to minimize costs.
Roads should be constructed when moisture and
soil conditions are not likely to result in excessive
erosion or soil movement, but have sufficient
moisture to achieve proper compaction. Advance
planning and using the right equipment will minimize
the construction foot print and reduce the cost of
mitigating soil disturbance.
When building a road, the intended use must be
considered. Build the road to accommodate that
use. For example, an unsurfaced road is the most
economical option, but its use will be limited to dry
periods to avoid excessive rutting. Gravel surfacing
a road can significantly increase the cost, but will
provide all-weather access, reduce road maintenance
costs, and improve water quality protection because
the soil is covered with a weather resistant surface.
Abandonment should be considered if a road is not
neededfor management activities, if serious erosion is
likely, or excessive maintenance is required to protect
water quality in nearby streams. A properly abandoned
road has been left in a condition where four-wheel
drive vehicles cannot use the road and where adequate
drainage without further maintenance will prevent
future erosion.
Management Considerations
There are a range of options for abandonment, but
all abandonment plans should include these elements:
•Removal of unstable side-cast or fill material, placing
it against the cut slope or in another stable location
•Removal of water crossings, reestablishing the
natural streambed in its original location
uAdequate drainage without maintenance
uWater bars at natural drainage points
Best Management Practices
•Non-compacted roads should be given several weeks
to settle before log haul or other heavy truck use
•Compacting the road sub-grade:
uEnsures a solid earthen structure with minimal
potential for failure
uExtends the life of the running surface
uReduces sediment runoff
Additional Resources
This brochure is intended to give a general overview of road design, maintenance and abandonment as outlined
in Washington’s Forest Practices Rules. There are numerous state resources available to forest landowners. For a
more comprehensive illustrated guide on Washington’s Forest Practices Regulations for forest road construction,
maintenance, and abandonment published by the Department of Natural Resources, visit their website at www.
dnr.wa.gov/forestpractices/illustrated, or call 360-902-1400. Additional information is also available at the DNR’s
Small Forest Landowner Office: www.dnr.wa.gov/sflo or 360-902-1415.
Washington Forest Protection Association
724 Columbia Street NW, Suite 250
Olympia, Washington 98501
360-352-1500
www.wfpa.org
[email protected]
Printed on recycled paper