Newfield Bridge weir no more....

Twenty-five years ago, I walked the Pennine Way parallel to the River Aire and stopped below Newfield Bridge for lunch. I imagine my casting arm was twitching slightly at the sight of the limestone stream with its clear water, mossy stones, and marsh marigold fringe. The white-water cascading over the weir was framed neatly through the arch of the road bridge, picturesque yes, but certainly not natural….

Almost 20 years later and I returned to that very spot with local EA Fisheries Officer, Pete Turner. I’d not long arrived in Yorkshire with my WTT cap on, and he was giving me a whistle stop tour and introduction to the Upper Aire Project (more of which, later). I looked at it then objectively with my fish passage polaroids on. We both agreed it was one for the wish list of removals; a clear impedance to free fish passage up and downstream for ~11km, 1.3m high and 9m wide, and the flat, featureless surface of impounded water upstream was reflected on the bed by tonnes of accumulated sediment held in perpetuity by dressed limestone slabs ​‘stapled’ together with steel pins. 

Most WTT followers recognise how even relatively small, low-head structures can cause selective effects on river fish communities. If this is news to you, there are excellent blogs by Dr Paul Gaskell of WTT (here) and Dr Peter Jones of Swansea University and the AMBER project (here). This particular weir and associated water offtake infrastructure did not feature on the Ordnance Survey of 1846 but was recorded (with hydraulic ram) by 1896 so had been fragmenting natural river processes and fish populations for >100years.

Fast forward to early 2021 and various threads had started to coalesce. Anglers of Bowland Game Fisheries Association that regularly fished the beat were concerned about the weir structure as the bottom rows of dressed stone comprising the sloping face of the weir had fallen into the river like a glacier calving icebergs. I was keeping tabs on its deterioration whenever I passed to project sites further up the catchment. The land agent for the estate, and the tenant farmer were also concerned with perceived erosion around the structure. Hence, a WTT Project Proposal was put forward and accepted by all parties.

Funding was the next question. The Upper Aire (Land Management) Project to give it its full title was originally a partnership between the EA, Yorkshire Wildlife Trust, and Yorkshire Farming & Wildlife, to engage with landowners and reduce diffuse agricultural pollution. On the coat-tails of that excellent foundation, I represent WTT as the latest partner to kickstart ecological rehabilitation in some of the now protected channels and riparian zones. Tick!

The Aire at Newfield Bridge is designated Ordinary Watercourse and hence works to remove the weir required an application to North Yorkshire County Council. The EA Geomorphology specialists wrote a detailed report to accompany my WTT musings. My permit request stressed the rapid deterioration within the last 6 months documented via fixed-point photography, and to their credit NYCC were equally rapid in granting it. Their only proviso: if possible, to use some of the larger dressed stone slabs to shore-up scour protection around the bridge footings. No problem!

With virtually no rainfall reaching the channel at least for most of the summer, conditions were prefect for the removal toward the end of September (and ahead of the salmonid spawning season). As ever with these things, the stress and the time is in the build-up. The actual removal was a relatively simple job, despite the farmer leaving an amorous bull in the field which took a shine to my sedimats….turns out they are extremely absorbent! 

Before the plant entered the water, I raced around to record the status quo via nine fixed-point photography sites, set-up the time-lapse camera, electric fished the immediate vicinity of the weir to remove four larger and two young of year (YOY) trout to a safe distance >100m downstream, and then install the sedimats. Within 6 hours we had the weir dismantled and the larger stone blocks from the crest moved to shore up the footings of Newfield Bridge at the request and under the watchful eye of NYCC. There was no unnecessary manicuring; we wanted the river to redistribute the accumulated sediment naturally via rainfall events over time. 

After the plant had left the channel and the water cleared, I was checking on the relocated stone blocks at the bridge when a sizeable trout shot past my ankles, so I retraced my steps with the electric fishing kit. From a cursory sweep, I saw nine larger trout (three of which forged through where the weir had been), and ~20 YOYs. I assume that the larger fish had nosed upstream with the lift in water and slight discolouration, and the YOYs probably dropped in from the reach above. It was good to see almost immediate passage with ease!

Within days the Aire received a decent pulse of rainfall and the resultant increase in flow began to shift and sculpt the bed again. Obviously, this will evolve over time and continued fixed-point photography will be used to monitor change; some before and after images are posted above and below. Newfield Bridge weir was one of the last substantial barriers in the upper catchment and builds upon our work 3 years ago when we reinstated connectivity at Coniston Cold ~4.5km downstream. It also considerably extends the range of the DNAire project, which is reinstating fish passage between Leeds and Skipton