Woody Debris Removal from Rivers and Streams
This web page is also available as a handout in PDF format: Removal of Woody Debris and Trash from Rivers and Streams (PDF) 1 MB.
Not All Woody Debris is a Problem
Woody debris, such as trees, branches and stumps, is an important part of natural and healthy stream systems. In the upper reaches of streams, such debris increases channel roughness, dissipates energy, slows floodwaters and reducing potential for flood damage downstream. This material also forms a basis for the entire aquatic ecosystem food chain. Woody debris that poses little risk to infrastructure is best left in place, thereby saving time and money for more critical work at other locations. Hanging trees, natural material wedged into banks, and stabilized woody debris within a stream should be left alone most of the time.
In some instances, however, significant debris can impact flows by blocking bridge and culvert openings, diverting streams and causing erosion of banks. When debris poses a risk to infrastructure such as bridges or homes, it should be removed.
Woody debris blocking bridge openings should be removed.
Woody debris that does not pose a hazard should be left in place.
Removal of Problem Woody Debris May Not Require a Permit
Provided fallen trees, limbs, debris and trash can be pulled, cabled or otherwise removed from a stream or streambanks without significant disruption to the streambed or banks, a permit from the Department of Environmental Conservation (DEC) is not required. Equipment may not be operated in the water, and any increase in stream turbidity stemming from the removal must be avoided. Consultation with DEC can help determine whether, when and how debris should be removed.
Any work that will disturb the bed or banks of a protected stream (gravel removal, stream restoration, bank stabilization, installation/repair/replacement of culverts or bridges, objects embedded in the stream that require excavation, etc.) requires an Article 15 permit from DEC.
General Guidelines for Debris Removal
Woody debris helps stabilize streams, reduce erosion, and slow down highly erosive storm-induced stream flows. Brush and fallen trees in a stream also provide food, shelter, and other benefits to fish and wildlife. Leave in place any woody debris that does not pose a hazard.
Woody debris and trash can be removed from a stream without the need for an Article 15 permit under the following guidelines:
- Fallen trees and debris may be pulled from a stream by vehicles and motorized equipment operating from the top of streambanks using winches, chains and or cables.
- Hand-held tools, such as chainsaws, axes, hand saws, etc. may be used to cut debris into smaller pieces.
- Downed trees still attached to streambanks should be cut off near their stumps. Do not grub (pull out) tree stumps from banks. Stumps keep streambanks from eroding.
- All trees, brush, and trash removed from a channel should be removed from the floodplain as well. Trash should be properly disposed at a waste management facility. Trees and brush can be used as firewood. To prevent the spread of invasive species such as the emerald ash borer, do not move firewood more than 50 miles from its point of origin. DEC has additional information on invasive insects.
When is a Permit Required?
Projects likely to disturb a streambed or banks-excavating sand and gravel, digging embedded debris from the streambed, or using motorized vehicular equipment such as a tractor, backhoe, bulldozer, log skidder, four-wheel-drive truck, etc. (any heavy equipment) in the stream channel or anywhere below the top of banks-require either a Protection of Waters Permit or an Excavation or Fill in Navigable Waters Permit.
If you have any questions about when a permit is required, or you want to discuss permitting requirements, please call the Division of Environmental Permits at the Regional Office for your listed County.