Crossing streams to minimize erosion
This web article explains
how loggers and landowners can cross streams during a timber harvest
while minimizing sediment runoff and protecting the stream's aquatic
1. Make every effort to avoid streams and minimize stream crossings
2. Cross streams directly when necessary
3. Build and maintain effective structures to protect the stream
bottom and banks
and loggers will often work around three kinds of streams:
- Creeks that flow
- Smaller streams that occasionally dry down or freeze over
- Dry channels that fill with intermittent flow from snowmelt
All three types of
streams require some kind of protection during logging. Because
they are variable, soil erosion can be unpredictable. Rutting
on the sides or bottom of streams is harmful and should be avoided.
Landowners are partly responsible for ensuring logging activities
do not cause environmental harm to streams and lake waters.
Best management practices
for crossing streams
Refrain from crossing
streams when possible.
During the planning stage, arrange the logging activity to cross
streams as few times as possible or not at all. Refrain from logging
in the vicinity of streams or stream crossings.
Obtain permits to
The first step is to call
the county Soil and Water Conservation District office and the
regional NYS DEC office and ask for staff who handle water quality
protection permits. A Protection Of Waters Permit
is required if the timber harvest somehow crosses these protected
streams, whether temporary or permanent.
According to the NYS
DEC, all waters of the state are provided a class and standard
designation based on existing or expected best usage of each water
or waterway segment.
- The classification
AA or A is assigned to waters used as a source of drinking water.
- Classification B
indicates a best usage for swimming and other contact recreation,
but not for drinking water.
- Classification C
is for waters supporting fisheries and suitable for non - contact
- The lowest classification
and standard is D.
Waters with classifications
A, B, and C may also have a standard of (T), indicating that it
may support a trout population, or (TS), indicating that it may
support trout spawning (TS). Special requirements apply to sustain
these waters that support these valuable and sensitive fisheries
resources. Streams and small water bodies located in the course
of a stream that are designated as C(T) or higher (i.e., C(TS),
B, or A) are collectively referred to as "protected streams,"
and are subject to the stream protection provisions of the Protection
of Waters regulations.
stream "C" in the Finger Lakes region
Small ponds and lakes
with a surface area of 10 acres or less, located within the course
of a stream, are considered to be part of a stream and are subject
to regulation under the stream protection category of Protection
To determine the classification
and standard of a given watercourse, contact the Department of
Environmental Conservation regional office responsible for the
area in which the watercourse is located.
The DEC can also issue a more straightforward
permit through the Standard Activity Permit Process (SAPP). These
are appropriate for simple logging jobs that do not involve many
stream crossings and will help ensure you are not at risk of violating
Environmental Conservation Laws. A DEC Forest Ranger, can assist
you with questions about SAPPs.
In some cases, the building of
new logging roads may be considered a construction activity,
depending on how long and wide the new roads are. If this applies
to the planned timber harvest site, a DEC permit related to Stormwater
Discharges from Construction Activities may be needed. This permit
calls for a stormwater pollution prevention plan in compliance
with New York's Environmental Conservation Law. Contact the permit
division at your regional DEC office, or check with county Soil
and Water Conservation District staff.
small streams if the season and weather conditions permit
Very small streams are sometimes dry or frozen, making crossing
less harmful. If the weather becomes warmer or rainy, refrain
from crossing small streams.
Cross stream directly,
not on an angle.
Do not skid logs down a stream course.
Cross streams where
the stream bottom is stable and the banks are low and intact.
If a stream crossing is necessary, install an appropriate structure
- a bridge, a culvert, or a pole ford - to minimize rutting and
bridges to minimize sediment erosion and maintain stream flow.
photograph a planned stream crossing, noting potential obstacles,
steep slopes, or other erosion hazards. Select materials that
will not harm aquatic life. If the landowner would like a permanent
bridge installed, construct it to withstand a 50 to 100-year rainstorm
or flash flood. Consult with the county Soil and Water Conservation
District technicians to assist with temporary or permanent bridge
crossings to minimize erosion.
culverts to maintain stream bottom form and reduce sedimentation.
Size the culvert(s) to handle current and storm flows of water.
Consult with the county Soil and Water Conservation District technicians
to assist with proper installation of culverts. Failure to properly
size a culvert can lead to washed out roads and inaccessible forest
fords with rock or pole timber.
Fords that cross
intermittent streams and dry washes can be protected with small
logs placed side-by-side, small diameter pipe, or clean rock.
These materials will prevent cross rutting and ponding within
the logging trail. They should be removed immediately following
the timber harvest.
Stabilize the sides
of culverts to prevent erosion from the road.
sure the sides of the culvert are compacted, and / or reinforced
with cull logs.
Chain the culvert or bridge to a nearby tree so it can be retrieved
if it is washed away.
Where a logging
trail approaches a stream crossing, divert water into the forest.
If water collects and flows down a logging trail, it should be
diverted off to the surrounding vegetation with a broad-based
or rolling dip before it reaches the culvert or bridge. Do not
allow water on a forest road to flow directly into a stream, as
it will inevitably carry sediment. If it flows off to the surrounding
vegetation, the water will filter through the streamside zone,
trapping the sediment. The deck of the bridge (or culvert cover)
should be higher than the approach road to improve drainage away
from the stream crossing. Cull
logs can be embedded in the bridge approach, perpendicular to
the roadway, reinforcing the sides.
crossing structures during low flow periods.
Use temporary bridges
to cross streams when appropriate.
If a selected forest road will be unmaintained after the harvest,
a temporary bridge will protect the stream banks without incurring
Monitor stream crossing
structures during the timber harvest for plugging.
Bridges and culverts should not become filled with sediment or
clogged with debris or beaver activity. This would create a significant
erosion hazard as the water would then flow around or over the
41 in the NYS Best Management
Practices Field Guide lists culvert size recommendations.