Sayers Meadow News

River Wensum Restoration Strategy - A view from Sayers Meadow

A LAYMANS VIEW:

NOTES ON THE RIVER WENSUM RESTORATION STRATEGY FACTSHEET (EA 2008)

Broadly speaking, I believe from an angling/environmental point of view any attempt to improve the general state of the river Wensum is to be welcomed.

 Sayers MeadowThe strategy as described in the fact sheet suggests certain key actions which fit very well with our interests – with certain caveats.

 1.       REDUCING THE EFFECTS OF IMPOUNDMENT BY MODIFYING THE MILL STRUCTURES: hopefully this would open up the possibilities for fish migration (maybe for the first time in hundreds of years). This would be particularly beneficial for those species which naturally spawn in the headwaters. A cautionary note: the mill pools immediately below the structures are often the “honey pot” areas for fish on the Wensum, sometimes also used for spawning/nursery areas, IT COULD BE COUNTER-PRODUCTIVE TO REMOVE THEM OR MODIFY THEM EXCESSIVELY.

2.       RAISING THE RIVER BED BY INTRODUCING (OR REPLACING!) GRAVEL: should give a more “natural” form to the channel, in conjunction with the above. Certain species of fish and other life-forms are known to prefer clean gravel in any event.

 3.       NARROWING OF THE RIVER CHANNEL: should result in increased current speeds, hopefully keeping some areas at least relatively free of silt/sand deposits.

4.       INCREASING THE AMOUNT OF WOODY DEBRIS IN THE CHANNEL: I understand this would encourage silt deposition in key areas, leading to further narrowing and consequent increased current speed.

The strategy fact sheet comments briefly and I feel somewhat dismissively on problems

With WATER QUALITY; WATER ABSTRACTION; and AGRICULTURAL RUN-OFF. Surely these are still very much live issues – whilst water quality is apparently improving, abstraction is being “reviewed”. Just what this means is unclear; I am deeply concerned that in the event of prolonged low rainfall in the future, the river will be just as vulnerable as in the past.

Regarding agricultural run-off, and probably run-off from roads, built-up areas etc. I am somewhat sceptical as to the effectiveness of the Catchment Sensitive Farming plan. After the last two wet years, if anything there is MORE silt, sand etc apparent on the river bed than ever. Precious spawning gravels are absolutely choked with the stuff and gravel-jetting is considered necessary every year in an attempt to deal with it in the short term. Maybe I’m being sceptical, but the only way I can see excessive land run-off being effectively dealt with in the long term is by ENFORCING BEST PRACTICE.

Moving back to the bigger picture, whilst we are concerned at this point mainly with the area around Lyng, it is worth commenting that the ideal scenario would logically be to tackle the ENTIRE river system FROM THE TOP DOWN. Thus any impacts caused either by existing problems upstream or indeed the work itself could be dealt with as the work moved down. Without this approach restored sections will ALWAYS be at risk from potential problems emanating from upstream. If the “top down” approach was applied to the ENTIRE River, ideally ALL structures impeding fish migration would be modified, from the highest point right down to the tidal limit at New Mills.

Regarding the proposed work at Lyng, as I understand it the main focus will be on the heavily impounded section upstream of Lyng Mill, and probably will include some modification of the existing sluice/weir structures, which are currently in poor repair anyway. There is also scope for some further work on the stretch downstream of the Mill, where the Sayers Meadow Project has pioneered habitat restoration/diversification within the river channel. More of such work would be beneficial to the stretch, also the modification of the sluice/weir structure at the downstream limit (Lenwade Mill) to allow fish freedom to move up- or downstream.

As any work on these areas will impact heavily on two NACA fisheries, one of which is generally considered to be our flagship/blueprint for such projects, we should be seriously involved from the outset, and detailed modelling of any effects on our fisheries should be seen and approved by us and our landlord BEFORE implementation.

Tim Ellis, March 2009