Unnatural Barriers can help but some can prevenet the safe passage of Steelhead and other aquatic species bothe up the creek and down.
The Creek was littered with small dams used for flood control in the winter and to impound and divert water during our dry summer months. Some of these damns were not built with the understanding of Fisheries Science we have now. Others have fallen into disrepair and their deterioration has created hazards and issues in the stream bed.
Entry at the Estuary
There is no bridge over the creek at Linda Mar Beach for human and surfers to cross. At time this is solved by making damns of boulders and logs to provide passage for people without getting their feet wet. This is problematic for the anadromous Steelhead and Pacific Lamprey as they try and make their way from the Pacific Ocean to the Creek to spawn.
In the upper reaches of the South Fork, the North Coast County Water District has a diversion dam to supplement Pacifica’s drinking water in the time of emergency. Currently, the dam makes the upper reaches of this fork inaccessible for spawning steelhead.
Culverts and Channelization
Parts of the creek, especially at road over crossings have created some steep gradients and hydraulic steps that prevent fish migration in certain conditions.