Designing Rehabilitation Projects Using LWD

LWD-boulder composites or jams can be used to restore or replace lost slamonid habitat as complex pools and runs. The technique that is chosen depends on the stream size, as LWD will affect small and large streams differently.

In small to intermediate size streams (up to 20m bankfull width) LWD is used for:

channel stabilization -energy dissipation -sediment storage
redirecting stream course
creating a stepped
channel profile
excavating floodplain channels for overwintering habitat
providing habitat and refuge from predators and strong flows

In large streams and rivers (>5th order and more than 20m bankfull width), LWD:

redirects flow into meander loops
forms off channel habitat

Before undertaking any project, please refer to the "instream window" for fisheries work, and, obtain the proper permit or permission. When planning a project using LWD techniques, certain guidelines should be noted:

address unstable slopes
watershed restoration efforts should begin in upslope areas where unnatural activities have been the cause of their instability
assess the dynamics of the stream i.e. order, velocity, gradient, width etc. and consider the goals of the activity when deciding on the appropriate technique
gather appropriate materials to be used like the type of wood and proper equipment

Choose native wood material that is:

durable and will stand up to wear over time, such as western red cedar and Douglas fir, or;
less durable such as, western hemlock, sitka spruce, pine, and other hardwoods that provide rapid canopy shading with increased litterfall.

Commonly used tools for LWD complexing include:

chainsaws
axes -peaveys
polaskis
shovels
rakes
hoes
winches
hammers
drills
wrenches
pliers
wire cutters

Commonly used fastening techniques include:

fastening to boulders using epoxy resin
galvanized cable or chain
rebar typically driven 2.8 m into substrate with the top 10-12cm bent and driven into the log

Natural anchoring or unfastened applications can be accomplished by positioning LWD in stream so that it will not drift i.e. wedge LWD between trees or rock or bury ends in the bank. Most channel spanning structures will seal with sediment and organic material over the first couple years.