By Nathan Wilbur, Director, ASF Programs in New Brunswick
ASF and the New Brunswick Salmon Council (NBSC) remain concerned about alteration work that was completed on the lower reach of Two Brooks near its confluence with the Tobique River.
At this location, there is a major salmon holding pool and Two Brooks used to provide cold water to the head of the pool, thereby creating thermal refuge conditions for the length of the pool.
A wetland and Watercourse Alteration (WAWA) permit was granted by the provincial Department of Environment and Local Government (DELG) and federal permission from the Department of Fisheries and Oceans (DFO) to infill an active channel of the brook and divert it into a floodplain channel.
Original confluence of Two Brooks and the Tobique. Also showing is the campground and exposed pipes.
The brook now flows into the Tobique River near the tail end of the salmon pool, approximately 140 m downriver of the original outflow. In addition to the diversion of the brook and bank hardening using boulders, the old Two
Brooks channel was in-filled. This work was approved as part of a campground construction on the floodplain of Two Brooks and the Tobique River. Flood marks on trees are evidence that during high flows, river levels regularly overtop the bank level.
We are concerned about this on several levels:
- The development's sewage system will be flooded whenever the river overtops its banks (expected during most spring freshets)
- The new location of the brook outflow decreases the capacity of the pool to serve as a thermal refuge for Atlantic salmon
- The hardened bank on the brook will continue to create problems, such as bank erosion and scour/incising within the channel itself. There is evidence of this already as material has been scoured, transported down to the mouth of the brook, and deposited. From there, it will make its way into the salmon pool.
What is most alarming about this situation is that a permit was issued to undertake the work without addressing necessary issues impacting salmon habitat. Without a geomorphic assessment, there was inadequate understanding of flood risks, erosion risks, and repercussions of alteration in general.
To avoid a situation of this nature in the future, ASF and the NBSC strongly suggest that DELG and DFO incorporate a professional geomorphic assessment requirement into the WAWA permitting process for projects of this nature. Major works, such as at Two Brooks, should be professionally assessed in terms of the hydrology of the site, the hydraulics of the watercourse, flooding potential, natural channel morphology, erosion thresholds, and so on. A geomorphic assessment would benefit both the regulators and the permit applicant to make better informed and sustainable decisions, with a reduced risk to the environment.
ASF and the NBSC are willing to work with DELG and DFO on the details of such a requirement and to which types of projects it may apply.