Lory called this afternoon saying the the dam had been lowered. We realized eventually that the missing filter had been replaced (which is necessary) but couldn’t understand why there was so much fresh mud on the dam. Then Jon realized that the city had ‘dug down’ the filter before securing it and tamped the mud and sticks back onto the dam. If the intake of the pipe is much lower, it means the pond can never return to its previous level, and runs the risk that there won’t be enough water for the beavers and they will simply start a new dam upstream.
Since April we have talked to public works about the need to restore the filter. We were advised by beaver management experts that it was problematic to let the beavers “learn” or have practice plugging the pipe. Worth A Dam suggested having Skip come out this January and restore the filter, but was assured that Skip had taught public works everything necessary to do the work themselves.
Unfortunately, looking at the effects of their January 13 efforts they appear to have lowered the filter height by ‘digging out’ the pond floor putting the mud on on the dam, presumably to keep the water level low. This means that no matter how hard they work the beavers can never get back their pond. And may not tolerate the change.
Skip was very clear that lowering the water level increased the risk that the beavers wouldn’t adapt to change and would instead simply rebuild another dam elsewhere upstream where they could have a better pond. Looking at the sunk filter it is hard to imagine that the pipe isn’t 6 inches lower or more, meaning the water height could never restabilize to last years level. Hopefully our flexible beavers will tolerate the abrupt change, but Worth A Dam will continue to monitor the situation.
Oh and for good measure they also ruined the secondary dam. Grr. Lets hope the beavers have more patience than I do!
