Natural debris in the creek -- branches, logs, and root wads --
creates food and shelter for fish and wildlife. Woody debris may need to
be repositioned, removed or partially removed if it threatens life or
property. Because removing woody debris can degrade fish habitat, it is
important to observe a situation before taking action. It is often best to
take small, incremental steps toward resolving a problem.
Woody debris should be left in the creek, unless it causes flooding or
erosion that threatens life or property (a house, utility pole, or other
structure), or speeds up natural erosion processes.
Woody debris may have to be repositioned or removed if it obstructs
creek flow and causes upstream flooding, or if it causes streambank
erosion by redirecting flow.
If fallen trees or branches are causing bank erosion, trim the portion of
the woody debris that is above the water. Try to leave the main stem or
root wad intact.
Most fish can swim through or around debris barriers. If you know that
fish cannot swim through a barrier, contact the California Department
of Fish and Game (916.445.0411). Removing barriers requires a Section 1603 Streambed
Alteration Agreement.
Brush, grass clippings, or other materials must not be thrown into a
creek or stored near creek banks to be carried downstream by wind or
rain. The brush may create a debris jam downstream on someone else’s
property or block a culvert.
If you are unsure about managing woody debris, contact the Natural
Resources Conservation Service at 925.371.0154.
Source:Creek Care: A Guide for Residents in the San Lorenzo Creek Watershed (Alameda County Public Works Agency)