Better hydrology, better habitat, better fish!
We at Redd Fish Restoration are in the process of building a series of big engineered in-stream wood structures in hiłsyaqƛis (Tranquil Creek) in Tla-o-qui-aht First Nation territory, using second growth trees to replicate the types of structures that would’ve been present with old growth ones prior to industrial logging, and we’re doing so to create channel complexity and habitat for fish.
Historically, big old growth trees and their roots acted as hard points along the riverbanks, diverting water flow away and downwards to create a narrow, deep and cool channel. When those trees fell into the river, they diverted the water to create pools, eddies, and all sorts of habitat complexity that fish love. Yet when these riparian forests were clearcut logged back in the 60s, and then the surrounding hillsides clearcut logged in the 70s, the complexity of this river collapsed.
The lack of mature trees and roots on the hillsides, riverbanks and floodplains created widespread erosion, sedimentation, rapid channel migration and simplification of the stream channel with less structure and habitat features for fish.
To help this watershed recover those ecological processes and to help give our wild salmon more habitat to help them survive, we’re building these structures that have all been specifically designed to work with this river in a particular way. Using detailed engineering plans for each structure, we arrange second growth trees with root wads facing forwards and secure then with vertically driven logs to drive water downwards, scouring a pool before flowing around the structure to create a deep, meandering channel.
These structures and all the restoration work being done is no substitute for a healthy river, and it’s a heck of a lot easier to protect and conserve than it is to restore, but this work provides a bandaid of immediate habitat to help bolster the rapidly declining salmon populations in this watershed, whose nutrients will help feed the surrounding forests themselves so that they may one day be big enough to maintain this process in their own.
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