We spent Wednesday and Thursday last week learning how to construct leaky barriers at three different locations across the cluster; each where channels begin to flow in the wetter months.
The idea is to let ‘normal flow’ pass through unobstructed, but temporarily hold water back during periods of high rainfall. This water is then released more slowly into the Arkle, thereby reducing the peak flow of the beck.
The barriers are constructed by laying a large foundation log across the channel, bedding it into each side, and staking it to hold it firm. Subsequent logs are laid in an X-shape on top of this; before smaller branches and brash are woven through — plugging any gaps, and making the barrier more solid. (A simple ‘shake test’ soon showed whether or not our barriers would stand up to increased water pressure!)
Where suitable trees were located along the side of the channel, we used hinge cuts to lay ‘living logs’ as the foundations. We also harvested willow from elsewhere on the cluster, staked this in at either end and interwove it throughout the layers of logs and brash, adding another regenerative element to our leaky barriers.
It was very rewarding — and enjoyable! — to see the constructions take shape, and in several places the water began to pool almost immediately.
The irony is not lost however that 10 people spent a considerable number of hours across two days on a job that a native semi-aquatic mammal would do naturally…
We wonder what mark they’d give us out of ten?
A huge thank you to Rhiannon O’Connell from the Yorkshire Dales Rivers Trust, for leading the works, and to all the volunteers who helped on the days.
Look out for our next installment of Natural Flood Management works…coming soon…