This has nothing to do with dredging. This is a project aiming to get fish downstream without being killed in electrical generation. As fish follow the greatest water flow, the intent is to attract them away from that with pumps (creating a stronger flow) to get them downstream past all the dams.

Dredging is very damaging to aquatic habitat.

North Fork Reservoir has never been dredged.

LydiaVmars said
It's basically a way to dredge the river. They want to improve the habitat by dredging the entire North Fork Reservoir/Lake. I'm pretty sure they just did this a few years ago, but this seems to be a much more massive mission. The entire North Fork Res. will be closed for a while. Shame, it brings a lot of business to the Estacada community in the summertime. 

I think maybe you're getting the recently completed (2013) project at Faraday Lake confused with this project. Only the marina and store at Promontory are slated to be closed until summer 2016. The reservoir will be available for recreation, according to the information from PGE.