Phillips, J., Olis, M. and Veldhuisen, C., 2012. Channel and Fish Response to the East Fork Hooper Creek Culvert Removal. Skagit River System Cooperative, La Conner, WA. pp. 38.

Culverts on forest roads can impact movement of fish and sediment. They can block
upstream access and limit the migration of anadromous and resident fish if they are not
designed and installed to provide fish passage. This is often due to high flow velocities in
the culvert and/or large outfall drops that limit upstream movement. In recent decades,
there has been an ongoing effort by forest land managers in Washington to replace these
barriers with road crossing structures that allow for fish passage as well as high flows,
sediment and debris.
In October 2008, forest landowner Sierra Pacific Industries (SPI) elected to replace an
undersized fish passage barrier culvert with a bridge on the East Fork of Hooper Creek
(Figure 1). The road work was implemented as a part of their Road Maintenance and
Abandonment Plans (RMAP) work for this area.