The project will construct full-spanning logjams to reduce stream energy, trap sediment, & increase cover, holding pools, tail-out spawning areas, & off-channel & side-channel habitat. Independent instream LWD will be placed downstream from the jams where needed to reduce bank destabilization. Early aerial photos were analyzed to identify log jam & side channel locations on the lower Sekiu River mainstem before the area was logged. When heavy logging began, old-growth timber was rafted down-river. Existing jams were removed & the channel was scoured. The old jams no longer exist, & the river has largely abandoned its side channels. Past activities & on-going disturbance have created a stream channel that lacks large woody debris & short-term sources for wood input. The Sekiu Rivers high flow during winter months allows it to flush most wood that comes into the channel. The proposed jams will trap wood until the riparian timber grows large enough to resist flushing. The project will rebuild large complex jams and bars like those present before intensive logging began. The jams will provide significant habitat for salmonids & their prey. Logjams will be built around 1-4 key pieces (dbh . 48) with rootwads that meet size criteria to resist mobilization in the channel during high flows. Roughly 15 - 20 smaller trees (dbh 16 - 30) will be placed amongst the key pieces to build up the jam. We expect that other LWD will also be recruited over time.
