An angler's journal

An angler's journal

Wednesday, 6 November 2013

Angling - Is there a future? (Part 1)

Like many, this season has been hit and miss on the angling front. In fact, as far as barbel are concerned it's been a near disaster. Only one double and fewer barbel than this time last year got me thinking. Granted, the summer's weather conditions were far from ideal with low, clear rivers the order of the day. However, with the rivers looking more ideal following our recent wet and mild conditions, the barbels' presence is still proving to be elusive. Therefore, are there other influences at work? Over the coming weeks I am going to discuss some of the main dangers to the fish population on our natural waterways and see if this season's form is a sign of things to come.

Hydro Power

Pershore's weir: a distant memory?
For those that are not aware, hydro power is a method of generating electricity using the water's flow. Of course, this is not a new idea with small water mills providing power in various guises all over the UK for many years. However, with the government applying pressure to source power from renewable sources, larger schemes are being planned and implemented on our rivers. There are number of issues that anglers and indeed any conservationist should be wary of. There is such a scheme being constructed a few miles away from me at Pershore, a small market town on the banks of the Warwickshire Avon. With this in mind I am going to highlight the key issues.

The plan has been proposed by the landowner, Mr C Hudson, and appears to have got the full backing of the Wychavon District Council. Indeed the development is now under construction. From an angling perspective there have been many concerns with regard to how the development will affect the flow and in turn how this will alter fish spawning grounds.  

Indeed, the Angling Trust's Alan Butterworth said, “I have commented on over 70 schemes on behalf of the Trust in the past year and this is by far the worse I’ve seen. The way that the EA has dealt with the proposal and acceptance of this scheme is nothing short of shocking.” 

In reply, the Environment Agency defended its stance by issuing the following statement: “In summer 2010 we issued an abstraction licence in Pershore with strict terms and conditions to protect fish, their migratory passage and the wider environment. These include ensuring a certain flow of water over the weir, especially during the fish spawning period, and a screening requirement to stop fish entering the turbine.”

The landowner's initial application to Wychavon District council is available online [here]. As part of the plan, a fisheries assessment was requested [here] and Fishtek Consulting carried out a detailed analysis together with computer aided models to predict and compare the effect of the hydro power scheme on the river's flow and its likely effect on the existing spawning grounds.

An aerial image of Pershore weir showing the location of the hydro turbines
You may recall I mentioned that the Angling Trust commented that this was poorly thought out scheme. Interestingly, Fishtek based their report on fisheries data dating back to the 1990s. This was because no surveys had been carried out since and the Environment Agency did not see fit to commission one. The table below shows the species present in various locations along the Warwickshire Avon but you will notice one notable omission: Pershore, the site of the scheme. This was because Pershore was not included in the 1990s survey. It was concluded that Evesham is a similar site and with it being only a few miles upstream then it would surely be the same. Quite a lot of assumptions here!

The 1990s survey used in the planning process
There is also another huge anomaly as far as fishing is concerned. That is the lack of a barbel population. During the 90s, barbel were beginning to show in some areas of the Avon. These days they are present in most areas of the river and are probably one of the main target species for anglers. They of course enjoy pacier, oxygenated river stretches typical of habitat found below weirs. This means assumptions have been made without considering one of the river's major species using data that is almost 20 years old. 'Poorly thought out,' perhaps the AT had a point.

Before works commenced, Pershore weir obviously contributed to increased flow of the river Avon in this area. This in turn resulted in increased oxygenated water and clean gravel areas which provide excellent spawning grounds and habitat for juvenile fish. The following diagrams show the current depths and flow speeds.

The weir's current flows
Projected depths following the turbine installation
With the weirpool's hydro turbines installed the river's flow was again analysed and predicted as follows:

Projected flows below the weir after turbine installation
Obviously, one of the biggest concerns amongst anglers is the effect on flow rates. Comparing the two images you can see that the effect is not as big as one might have imagined and the tail of the weir, important for spawning, remains largely unaffected. This leads nicely onto spawning. The increased flow and oxygenated water below any weir makes it an obvious spawning site on a river for many species that take advantage of the shallower water, clean gravel and plant growth. The diagrams below show the current spawning situation below the weir and what the effect of the turbines will be.

The current spawning situation at Pershore Weir
Projected spawning areas following works

The brown areas below the weir itself do not represent good spawning sites due to their depth and an unsuitable layer of fine substrates. This remains unchanged by the proposed hyrdo power turbines. You will notice that the tail of the weir provides some of the best spawning sites due to shallower, gravelly areas. Again, the proposed changes should not alter the effectiveness of these locations.

Fishtek Consulting (2012) offered the following key recommendations:

  • The turbine discharge is sited as close to the toe of the weir as possible maintaining the maximum distance from the region of spawning habitat identified.

  • The turbine discharges into the area of deep water in the left hand corner of the weir (looking downstream), forming an effective stilling basin to dissipate velocities.

  • The spawning habitat is mapped annually post installation to ensure that there is no  reduction. In the unlikely scenario of a reduction occurring, mitigation in the form of gravel addition or altering the flow should be considered.

  • The fish pass entrance should be located 1-2 m downstream from the turbine discharge point in order to reduce the potential masking effect that the turbulent outflow may have.

  • Compressible bumpers should be fitted to the turbine leading edges to eliminate fish damage.

  • It remains to be seen if Fishtek's recommendations have been implemented in full. However according to the study, negative damage as a result of the installation of hydro power turbines is negligible. Although it is worth noting that there were assumptions made on the species inhabiting the river following the use of old data that is not reflective of today's Warwickshire Avon. Therefore, the Angling Trust do have a point when they say a thorough study was not carried out. It does beg the question as to why a new survey was not carried out in the immediate area especially when the Environment Agency are supposedly the guardians of our waterways. Despite the fisheries analysis suggesting it's not all doom and gloom, only time will tell. The Birmingham Anglers Association (BAA) who lease the fishing rights from the landowner were not notified of the scheme. Since planning was granted, they are still waiting for any communication. As for how this will alter the access to the club's fishing rights, BAA's John Williams stated, "We will not know anything until the scheme is complete. Access to the fishing will be determined by the landowner's wishes." Not great news when the landowner has already demonstrated a lack of consideration for river users by failing to take part in any meaningful consultation. Basically, a landowner can do what they like regardless of what lease agreements have been previously put in place, or at least that's what is being suggested. It is a pity, in my opinion, that the landowner, the council or the Environment Agency could not have had a discussion with interested parties such as the BAA and the Angling Trust.  The BAA have seemingly lost fishing access to one of their prime spots without consultation and only future studies will determine whether the area's fish friendly habitat and attractive spawning grounds remain unharmed. I must admit there is something fishy (pardon the pun) with the ease in which this scheme found favour. Could it be that since the scheme will provide electricity for the nearby leisure centre, run by Wychavon District Council, it assisted in gaining full support? After all, this could cut the council's electricity bills so there is a slight conflict of interest. Did government incentives for green energy ensure this scheme was always going to be given the green light? There have been alleged accusations of money changing hands given the EA's lackadaisical attitude but of course this will only ever be rumour and conjecture. However remember, hydro power could be coming to a weir near you and you'll probably be the last to know!

    Pershore's locals have an online petition which you may wish to support [here].

    What is your opinion on such schemes? Would you be happy with the assurances made in the fisheries assessment? Would you welcome a scheme on a river near you?


    1. Look on the bright side, with all those chopped up silver fish the pike will pack the weight on!!


      1. Coops, the bit that really stands out for me is the lack of knowledge with regard to species. That survey from the 90s is so out of date that I find it impossible to predict an outcome when the range/distribution of species has changed.

    2. Wheres part two

    3. Work in progress, Anonymous. Thanks for looking.