Knottingley Hydro officially open

The Knottingley Weir hydro officially opened on Nov 5th 2017. The green contraption on the weir is the eel pass and the outflow from the hydro is in the immediate foreground just below the outflow from the fish pass.

The other photo shows Geoff Boycott (mike in hand) addressing the invitees just before he unveiled the plaque and switched on the hydro. The other person is Mark Simon, Chief Executive Officer of Barn Energy, the company whose project it is. 

 

Stopping flooding in Leeds – FAS2 consultation

Flooding on Kirkstall Road, Leeds at Xmas 2015Leeds FAS2 is the Leeds Flood Alleviation Scheme Phase 2. This major flood risk management scheme is being designed to substantially reduce the risk of any repeat of the Xmas 2015 flooding.

The Environment Agency and Leeds City Council have been working together for the last 18 months to come up with their outline proposals and these are laid out in this leaflet.

This is an interesting scheme, for at least three reasons:

  1. because of firstly the size (potentially £100 million)
  2. that they have taken a ‘whole catchment’ approach in which possible measure well upstream of Leeds have been explored and
  3. that ‘Natural Flood Management’methods, such as tree planting, land management, leaky dams etc have been considered.

The Aire Rivers trust has already been involved in a network of catchment-wide stakeholders put together to help inform the proposals and we look forward to the detail being released in due course. A scheme as big as this will inevitably have some short-term effects in the locale of the work and so we will be seeking appropriate compensatory and enhancement work to maintain and improve the river.

Meanwhile, you might want to read the leaflet and see what the proposals contain.

Harden Beck just got better!

Beckfoot Mill Weir on Harden Beck was independently identified by both Kevin Sunderland of the Aire RT and the Environment Agency as an obstruction to fish passage and an interruption to natural geomorphological process. EA fisheries data confirm that grayling are only recorded in the beck up to the weir, and since it is only ~750m from the confluence with the Aire, modification of the structure potentially opens up several kilometres of quality habitat for them, as well as improving connectivity for the local trout populations.

The weir no longer functions to supply a goit with water, and the owner was in favour of the ecological benefits of the proposed project from Professor Jonny Grey of the Wild Trout Trust. Jonny’s plan was to remove one or two of the large gritstone blocks and focus all the flow under low flow conditions through a gap, thereby removing the head drop of 40cm and the 50m impoundment of water upstream which has infilled with bed substrate over the years to become very shallow and of little use as habitat.

Beckfoot Golf Club, riparian owners on the right bank, was consulted by Kevin and gave its support. The project application was also assessed for flood risk by Bradford Metropolitan District Council (since the beck is not classified as main river) and approved. From a biosecurity perspective, the weir was identified as easily passable by invasive crayfish and hence not a potential barrier to their spread, by an EA crayfish expert, and Jon accompanied them on a torchlight survey on June 21st to determine their presence above and below the weir; none were found thankfully.

Last week, in a gap of good weather and hence low flow, work began. To minimise disturbance to the bed above, and the riparian trees, a 5-tonne digger was substituted by a jack-hammer, a Stihl saw, a 2m wrecking bar, and a lot of brute force! One block was broken up and all the material moved downstream to contribute to the natural substrate. A second block was loosened and will be moved further into the former weir pool to widen the gap, once the bed upstream has adjusted.

Fig 1: Pre works, flow is spread across the full width of the weir. Note shallow impoundment upstream

 

By the late afternoon, the beck was actively cutting down into gravels, cobbles and boulders that have probably not seen the light of day in decades. What was a shallow, almost stagnant pool above the weir is now a meandering riffle and there was a noticeable drop from the impounded level of ~10cm as measured by watermarks on large boulders almost 70m upstream. At the weir itself, there is no longer any requirement for fish to leap, and there is now a focal flow of deep water instead of the energy being dissipated across the full width of the weir and resulting in a v shallow skim of water which fish find difficult to negotiate in either direction.

Fig 2: tree branches are tied back to allow access for the Stihl saw to cut the stone blocks
Fig 3: One block removed and all the flow passes through the gap. Note the positioning of the remains of the block downstream as a feature to dissipate flow

 

This is just one of a series of low-head weirs throughout the catchment to be made more passable using funding held by Aire RT, and in partnership with the Wild Trout Trust and the Environment Agency.

CSO at Apperley Bridge spews out rags again

Yorkshire Water has cleared teh CSO gate at Apperley Bridge of the sanitary towels, wet wipes and other unflushables that were almost completely blocking it, a few weeks ago. A visit at the end of July produced photo’s that demonstrate that the system is disfunctional: from package labelling to humans’ flushing behaviour to filtering and then into our river. It’s rubbish!

Tree works on rivers

Earlier this year many of us expressed serious concern about the way in which the Environment Agency were undertaking tree clearance/improvement work on the Upper Aire. No need to repeat the details of the saga here because the important point is that the EA have learned from what they acknowledge was a pretty dire performance. The attached note outlines the results of in internal review which as led to improved planning and liaison before work is undertaken.

There is a difficult balance to reach between flood alleviation works and the needs of the ecosystem but we know that most of these recommendations have already been applied successfully in other catchments and look forward to working with the EA, the Wild Trout Trust and the angling clubs in the future to get the best for everyone.

More weirs made swimmable!

Aire Rivers Trust has agreed to fund work to improve fish passage and reinstate connectivity on several small to medium-sized weirs on tributaries between Bingley and Malham. The work is being coordinated by Professor Jonny Grey, Research & Conservation Officer for the Wild Trout Trust, in partnership with the Environment Agency and various other organisations and land-owners.

Ideally, these redundant weirs would be removed completely to reinstate a more natural channel form and flow of water, plus transport of material (cobbles / gravel) downstream, and reduce flood risk. However, other surrounding infrastructure that potentially could be affected by complete removal requires some thought. The proposed solution at each weir varies slightly because of the differing nature of each beck and immediate environs. Most will be ‘notched’ in some format, i.e. the crest of the weir will be lowered in a specific location to create a focus of flow during low flow conditions.

Eastburn Beck has been a particular focus for related work (see blog post, here). The last in a series of privately owned weirs just below Glusburn Bridge was notched in May. Jonny noted that there were trout fry in abundance during the works – a good sign of the population bouncing back from the previous year’s unprecedented flooding that effectively scoured out all the eggs and juveniles. The weir owner was delighted! The notch will allow them better access both up and downstream, and also reduce the amount of stagnant water and silted sediment upstream in the formerly impounded section.

Image (1&2): Eastburn Beck weir, pre and post notching

Kirkby Beck is much smaller than Eastburn, and much higher in the Aire catchment at Hanlith. The weir is less than 10m upstream from the confluence and hence is an immediate obstruction on the system. The local farmer agreed to a notch and several hundred metres of fencing to prevent livestock access from degrading the beck banks, thereby improving the habitat at the land water interface for birds, mammals, insects and plants, as well as fish. The work was carried out in May when the beck had all but dried up! The aquatic organisms living in such ephemeral streams have evolved to cope with occasional dry periods in all sorts of ways; with a notched weir, now the fish can recolonise more easily after having migrated downstream to avoid the low flows.

Turbines at Chapel Haddlesey and Knottingley

Two hydros and fish passes are under construction on the lower Aire.

Chapel Haddlesey

The turbines have already been installed and the baffles for the fish pass will be delivered in early June 2017. The fish pass and the two Archimedes Screws are expected to be in use by the end of June.

Knottingley

The two Kaplan turbines should be delivered in the near future. Work is still being carried out on the walls of the chambers. The photo shows the huge size of the chambers. Some earthwork has been prepared for the site of the fish pass but, as yet, the concrete base has not been laid. The fish pass will be a two flight one having a single resting pool. The latest date for expected completion will be some time in the autumn of 2017.

Walks around Bradford’s Becks

Friends of Bradford’s Becks have just published a (FREE!) guide to a series of walks around Bradford’s Becks. The booklet contains detailed guides to several walks around the area as well as background information on the becks, the wildlife to be found, the history of the beck and how to keep our watercourses clean. You ccan download a copy by clicking on the image to the left or by sending your name and address along with a 56p stamp to:

Friends of Bradford’s Becks
c/o Kirkgate Centre
39A Kirkgate,
Shipley BD18 3EH

 

Catchment Improvement Lead – an opportunity

The Aire and Calder Catchment Partnership, which is hosted by The Aire Rivers Trust, is  advertising a role to help lead the Partnership to the next stage of our development.
With funding from Defra we are now looking to issue a contract for someone to lead the initial stages of delivering our Actionable Plan and for extending that plan to include the views of additional stakeholders. The successful candidate will lay the foundations of the Plan ensuring that partners and others are fully engaged with the process and, in a better position to deliver ACCP goals.
Details can be found here and applications/expressions of interest are requested urgently.

A Place for SUDS

Sustainable Urban Drainage Systems (SUDS) are much talked about these days, but  what are they and what is the point of them?

Sustainable drainage mimics natural processes and reduces flooding by managing rainfall close to its source and wherever possible at, or near the surface. By building in permeable paving, channels, green roofs, swales, soakaways or ponds, sustainable drainage becomes a “city circulatory system”, slowing, storing and treating water that could cause damage. Well-designed SuDS should incorporate the four elements of water quantity, water quality, amenity and biodiversity wherever possible. They are fundamentally a way of slowing and reducing surface runoff in order to reduce flood risk, whilst at the same time improving the look of the urban environment.

Now CIWEM (Chartered Institution of Water and Environmental Management) recently published a very well-researched and informative study on the subject which supports their wider implementation:

Incorporating SuDS into developments can maintain local water balances and treat water pollution, whilst also supporting wildlife and delivering attractive community spaces

 

It’s well worth a read, so here’s a link to a copy for you to download.