Groynes Downstream of Blue Bridge (1999)

Interesting things are happening to Wessex rivers. New fences are restraining cattle from damaging the banks; ingenious methods, mainly using local timber and materials are being devised to narrow the river and thus to speed up its currents; and perhaps most crucially, underwater groynes are being installed to restore some of the diversity that was lost when dredging programmes straightened these rivers and badly damaged their natural habitats.

Dorchester Fishing club is not asleep. Already, you may have noticed the new cattle fences that line many of our stretches along the Frome and the upper Stinsford. Watch out for further, much-needed fencing that will run the length of Poundbury and which waits only for drier ground conditions.

However, you are less likely to have seen the five groynes installed downstream of the Blue Bridge. Last season this important stretch was a disaster area: the current was uniform, very shallow yet sluggish; the riverbed was silted and covered in silkweed; there was an absence of Ranunculus; and very few sizeable trout remained in it. Few members bothered to visit it. John Grindle and John Aplin decided that things had to change so they studied ways to turn this featureless stretch, into a diverse, productive ecosystem, settling for a series of groynes, made out of willow stakes and hazel faggots.

In the three months since these groynes were installed, astonishing changes are underway. Already, deeper runs are found alongside gravel shallows; currents vary from powerful, surging and fast, to gentle and steady; eddies and backcurrents throw up new banks of silt, which add important habitat; fish are moving back in numbers and size. As if to enter into the spirit of conservation, the heavy winter rains have ensured waving beds of bright green Ranunculus. From last season’s travesty of a trout stream, this stretch is changing towards what it must have been like in 1877, when the Blue Bridge was built and our Club established.

Who have done all this work? Who hammered all those willow stakes deep into the river bed, in a line at an upstream angle of 45 degrees? Who tied in the hazel faggots, to complete the groynes that cleverly criss-cross the Frome right down to Mayo’s boundary? I’ll tell you. John Secretary and John Keeper were the planners, inspiration, and workers, crucially supported by the muscle and ideas of members, Peter Leatherdale, Rod Crane, Trev Stroud & Adrian Simmons. They are owed the warmest of thanks from all members.

This is just the beginning of an important project. Weekly, we are checking that the groynes do not damage the banks and riverside fences. Already, we have modified the first groyne to improve the direction of the main flow and to eliminate erosion of the steep, crumbly bank, where the groyne creates a back eddy. A systematic note is being made of any observed changes to the river, fish life, plants and bankside habitat. Perhaps equally important, we intend to put into practice what we learn, on other stretches of our waters, which we have identified for similar improvements.

The only bad news is that the fishing won’t get easier – just better!
John Ginifer

July 5, 1999 by Filed under: History, River Work