Over the past two months we have been busy walking the watersheds bringing new members up to speed on the extent of our watersheds. During January we did some cabling of large first growth logs that had moved downstream from a large logjam further upstream.This was one of those tasks that if you leave it flood waters will create more erosion from the redirected flow against the bank creating a problem for the landowner or do what we did and secure the logs into a log structure that was constructed many years ago giving the structure more complexity while providing much needed habitat for fish.
The decision was made to move and secure the logs during a period of low flow when the logs where sitting out of the thalwag [flow]. First we tried the chain saw winch, which proved to be too much weight and resulted in the cable breaking after several attempts to move the larger of the two. We next rented a turfer, a hand winch capable of moving over 2,000 kilos, slowly the log began to move as it inched painfully slow towards the spot where we could cable it to the existing structure. Over two days we worked to move the log around 40 feet eventually bringing it in behind the large log sticking out of the downstream end of the structure.
For the second log we were able to use the chainsaw winch again as this log was less than half the size of the first, rigging up some blocks to increase the purchase of the winch we sucked the log in behind the first where we cabled them both into the existing structure creating some awesome habitat for the fish while allowing the flow to move back during periods of high water to the original thalwag. This was an awesome achievement without the help of machinery and most of all gave the volunteer a good sense of achievement making them proud of what they had accomplished.
Over the past month since we moved the logs we walked downstream and cabled into the bank another large chunk of first growth across the face of a existing log jam making it more stable and creating more cover for the fish especially when water levels drop and habitat with cover becomes scarce.
We also went back in and planted some Spruce trees behind the structures and on all the high spots on the gravel bars. This will create some stability to the stream by the action of the roots binding together the gravel in a matrix or roots thusly helping to further stabilize this area of the stream. When the Spruce take hold and begin to grow taller they will provide more shade for the stream while keeping the sun from warming the water during the hot summer months, which is critical to small juvenile fish trying to survive within the stream. Spruce seems to be Beaver resistant maybe due to its spiky trunk and branches not to say that they will not eat them as was the case with several trees down in the estuary. Now to clarify it was due mainly to a over zealous volunteer pruning off the lower branches causing them to bleed sap which in turn attracted the Beaver who not being one to miss a treat devoured the trees leaving only the stumps, another lesson learned we hope. We spent time repairing our fish fence at Swan Lake last month and now our next job is to repair the frame structure within the stream when flows over the next week go down and we can access the lower screws to pull the rails back into alignment after being knocked out of place by a large log which came downstream during the last big rain event. The last big rain caused our previously cabled logs to lift and move further onto the gravel bar further stabilizing them and protecting the bank from more undue erosion.
All this talk of erosion sounds like it is a bad thing for the stream in fact it is the natural process of hydrology as water flows down stream creating currents and back eddies carrying any eroded material downstream to eventually arrive at the sea to help make what we call a beach. Without erosion of stream and foreshore we would have no beach so as you can see to prevent all erosion would have negative effects on habitats miles away from the erosion site. This is no more evident along the foreshore where misinformed residents rushed to place truckloads of rock in front of their homes to so called prevent this natural erosion. Oh we are losing our lawn is the cry as the contractor places the rocks on the public beach giving the landowner more land while creating more erosion than they try to prevent. This time the erosion is not horizontal as the wave energy bounces along the beach it now has to hit a solid rock wall driving the energy in a downward direction. This results in the erosion of the beach substrate pushing it deeper and deeper until when the low tide goes out it just drops lower and still the water remains now along the base of the structure and if not deeply buried will lead to premature failure of the wall.
Next month we will be installing our fish fence to count the downward migration of the fry we placed in the lake last year. This is one of the exciting times when you go to check the box not knowing what or how many fish will be in the box.
Last week we took a hike up to the top of Nanoose Creek watershed, though a tough hike straight uphill the view at the top was spectacular to say the least.
We also planted more trees within the estuary at the head of the bay in our effort to return some of the riparian vegetation from when years ago most trees where cut down to allow more sun to the adjacent landowners property. This created a section of the stream bank with no vegetation to shade and cool the stream during the hot summer months. After years of planting trees of all species we have come to rely on the Sitka Spruce for being the most resilient and as mentioned prior not very attractive to Bucky the Beaver. As technically we are in the coastal Douglas fir zone I was told that no Spruce would grow this far south? I thought then just a minute are there not some very mature Spruce at Brandon Lake and several other areas around the mid Island. Of course Spruce will grow here and they do grow very well, the problem we have with Fir and Cedar in the estuary is during times when food is scarce the Voles and Mice feed on the bark and end up killing the trees by girdling them. The Cedar seems to get going then along comes a deer and browses off the tops. Then we get the Beaver who like all trees and shrubs even when we have driven Willow and Red Osier stakes along the banks to root if there is a Beaver lodge or tunnel under the bank they pull them down into the hole just like Bugs Bunny eating the Carrots from his den and chew them up giving a new meaning to take out delivery.