On the 2nd and 3rd of April Ed Mills and Frank Johnson carried out the following work on the beaver baffler:
We righted the barrel that protects the inflow to the three 6″ pipes, and placed a concrete block under the barrel to keep it upright. The water depth at that point was well over the tops of our waders, and we had to move sheets of ice away to gain clear access. Water temperature is about 4 degrees and the air temperature was above +5, although not by much.
We then cleaned out both of the barrels with a rake and a hook. A considerable amount of sticks and mud had been placed in both barrels by the beaver. A wire mesh (1″ square) was fashioned by Ed and installed at the tops of the barrels to mitigate further ingress by the beaver.
The next day we assembled 90 feet of chimney rod, equipped with a 3″ diameter tool designed to clear debris without getting stuck in the pipes. This was pushed through all six of the pipes from the downstream end (in addition to the 6″ pipes there are three 4″ pipes), and the pipes were cleared right through to the barrels. There were a number of blockages and the smaller pipes especially released a fair amount of silt.
After this work there seemed to be very good flow in all of the pipes.
We estimate that this system should now capable of reducing the lake level gently at a rate of about 10 mm per day. We shall monitor the state of the system as often as is possible, and plan to have a review in two weeks and again in four weeks’ time during which period most of the spring runoff should occur.