State of Our Watersheds: Culverts Blocking Fish Access in Kitsap

Culverts mess up fish habitat. And Kitsap County is filled with them.

In fact, there are enough culverts to partially or fully block salmon from accessing 78 miles of habitat in East Kitsap County, according to the 2016 State of Our Watersheds, recently released by the tribes of NWIFC.



Nearly 100 percent of the drainage units are impacted by high road densities while 37 percent are negatively impacted by stream crossings.

High road densities require stream crossings, culverts and other structures that constrain stream channels. The removal of fish passage restrictions in streams that provide important salmon habitat was identified as high priority in the East Kitsap Salmon Recovery Plan since they create physical obstructions that impede access to spawning and rearing habitats.

From the report:

Recently stream mapping work in East Kitsap suggests that culverts and other man-made obstructions block considerably more habitat than (the estimated 78 miles) indicates.”


This analysis shows that almost every watershed in the East Kitsap Study area is impacted by high road densities and a significant number are also impacted by stream crossings. The proper function of salmon-bearing streams may be at risk when road densities exceed 2 miles of road per square mile of area and cease to function properly at densities over 3 miles/square mile. Streams have also been shown to approach poor biological conditions when exceeding 3.2 crossings per mile of stream length.