FLETCHING MILL WEIR:
Early History of the Site
Fletching Mill worked until 1939 before falling into disuse, leading to its demolition in 1951. East Sussex Record Office has a mortgage document dated 30 December 1703, but it is likely that the mill, and thus the pound above its weir, was built well before this date. When construction of the Sussex Ouse Navigation reached the Mill in around 1793 the pound was straightened and deepened in places, but the water level was retained since any change would have disrupted the mill’s water wheel. Thus the pound above Fletching Mill Weir was at a fixed level for well over three hundred years.
After the Navigation closed in around 1868 the upper lock gates were replaced by sluices that retained the water level for mill operation. These sluices allowed a considerable proportion of the flow of the river to be passed along the former navigation channel to the west and under the road through the former navigation bridge to retain the navigation channel as clear-flowing, unsilted stream. The original by-wash weir continued to carry the remainder of the flow through the narrow eastern channel and under the road in the far smaller arch bridge. More recently a concrete fish pass was built adjacent to the by-wash weir.
History from 2001 to 2008
Straw bales carried down the river on a flood in 2001 caused damage to the sluice, rendering it inoperable. A large steel plate was fitted between the upstream training walls of the lock chamber as a temporary cofferdam whilst repairs were organised. A large sum of money (believed to be in excess of £61,000) was spent on these repairs, including the provision of an electricity supply and associated control equipment to automate the operation of the replacement sluice gear. However, when the gates that had been ordered for the new sluice were delivered they were found to be incorrectly sized and would not fit. It seems that no additional money could be budgeted at that time to correct this error and the scheme was abandoned.
The temporary steel plate had a small hole cut in it (roughly 30cm square) to pass compensation water down the former navigation channel. However, it passed far less flow than had the sluice, with the result that more water now passed over the by-wash weir. This had the effect of causing scour damage to the northern bank downstream of and adjacent to the weir. It also overloaded the small arch bridge under the road, causing the road to flood more frequently than in the past and potentially endangering the stability of this smaller of the two road bridges.
In March 2008 Royal Haskoning, on behalf of the Environment Agency, issued a consultation leaflet “Fletching Mill - What are your views?” to a number of local interested organisations and individuals. This described the events above with the notable omission of the abandoned repair scheme. It correctly summarised the situation regarding the safety of the weir and the small, arched road bridge. It stated that the two solutions under consideration were “modification of the weir at the head of the bypass channel” and “re-grading of the by-pass channel” so “the water level would be gradually raised to that of the existing weir at the head of the by-pass channel”.
Roy Sutton, Honorary Consultant Engineer for the Inland Waterways Association, inspected the site, agreeing that the existing weir had been rendered unsafe and that the present arrangements put too much flow down the by-wash channel. His report dated April 2008 and sent to Royal Haskoning at that time, whilst supporting the general proposals made in the consultation document, also suggested a modification to enlarge the existing ditch across the site to divert a greater proportion of flow into the former navigation channel and under the larger bridge to the west, thus taking pressure off the by-wash channel road bridge.
At a public consultation meeting at Fletching Village Hall on 8 September 2008, Environment Agency and Royal Haskoning staff proposed a radically altered solution from that outlined in the original consultation leaflet. In this new proposal the weir would be completely destroyed, lowering the water level of the pound above the former lock and mill. EA staff present stated that the new proposal would improve fishing by removing a barrier to migration, that the new solution was ‘sustainable’ and that they were legally obliged to implement it. Bob Draper of the Sussex Ouse Restoration Trust and Roy Sutton were both present at the meeting and argued that this new proposal would (i) damage the ecology of the river and its surrounding land that has developed over more than three hundred years, and (ii) increase the flood risk in areas downstream of Fletching Mill, especially Uckfield and Lewes. Two riparian landowners and the farmer of the majority of the land, also present at the meeting, expressed their strong objections to the new proposal.
In an ill-tempered exchange it was stated that the situation had been made worse by EA inaction since 2001 whilst the full flow was passed over the by-wash weir and that the solution was contrary to EA’s own Catchment Flood Management Plan for the River Ouse and also their published national policy on the improvement of biodiversity and the importance of both the conservation and re-creation of meadows and wetlands for wildlife.
2008 Consultation - Former Ecology of the Surrounding Land
Before 2008 the riverside land upstream of Fletching Mill was water meadow. It was grazing land at small freeboard above the stable water level of the river. Significant areas were slightly below the retained river level, draining into a parallel ditch that joins the by-wash channel near the smaller, arched road bridge. There were ox-bows where former loops of the river retained water throughout much of the year. The low freeboard caused the land to be inundated by flooding several times a year. In the consultation SORT warned that if the pound above the weir were to be lowered this land would be permanently drained, destroying its fragile ecosystem and argued that before any proposal was taken forward a full environmental impact assessment should be undertaken, including a specialist survey of the species in the riparian land upstream of Fletching Mill.
2008 Consultation - Risk of Downstream Flooding (especially in Lewes)
Before 2008 the combination of the weir/sluice and the small freeboard to the pound ensured that even relatively small floods overtopped the banks above the weir, causing water to flood the water meadows, re-entering the river by flooding over the road or through the ditches leading to the by-wash. This system, described in “How Weirs Store Floodwater”, delayed the water in its journey downstream so it did not reach the confluence with the river Uck, Barcombe Mill or Lewes until the peak of flooding had passed and the flood was thereby attenuated. In the consultation SORT warned that, if the weir were removed, this water would form part of the peak flood, worsening the situation at Lewes. The EA proposal ran contrary to the need for upstream storage of floodwater presented in its own Catchment Flood Management Plan.
2008 Consultation - Ecology of the River
Before 2008 the river impounded above Fletching Mill had been a slow-moving, deep channel for over three hundred years. It had developed an ecosystem normal to a slow moving deep channel. SORT warned that lowering the water level would radically change it to become a fast-moving shallow river in a deeply incised channel and with a far poorer ecosystem very similar to that downstream of Sheffield Bridge. If (for instance) depressed freshwater mussel (a rare species typical of a slow moving deep channel) had existed in the pound above Fletching Mill would the water level still be lowered? SORT argued that a full species survey be undertaken before any change.
2008 Consultation - Effect on Fishing
Royal Haskoning’s consultation leaflet “Fletching Mill - What are your views?” stated that there was “limitation of fish passage at the site”, even though the fish-pass was in a good structural condition. It is uncertain on what facts this assertion was based. It is true that no salmonid migrations had been seen at this fish pass for a number of years. However, the local riparian landowners stated that this lack coincided precisely with engineering changes made to the weirs and associated structures at Barcombe Mill and the session of stocking sea trout smolts by the EA. Prior to those changes, regular salmonid migration activity was witnessed, apparently unhindered by the construction or condition of the existing fish pass. Thus, SORT argued removal of the weir would not aid fish migration but that the many obstructions to salmonid migration downstream of the Fletching is the main reason why so few fish reach the site. SORT argued that destruction of the weir would in fact lead to the draining of the deep-water pound above, completely removing this prime habitat for coarse fish and thus having a distinctly negative effect on the coarse fishing presently practiced (with fishing rights let to an Association).
2008 Consultation - River Naturalisation
In 2008 the Environment Agency argued that lowering the water level would make the river more natural and that the river would, over the course of time, develop its own natural width, shape and ecology. SORT responded that might be the case for some ‘river restorations’. However, past experience on the Ouse suggested that it would not happen here because the construction of the navigation in the late eighteenth century both straightened and deepened the river. The course of the flow is shorter and (unless it is restrained by barriers such as Fletching Mill weir) the river is steeper than it would naturally be. This results in the flow being faster and the river tending to incise itself far deeper than a natural river would. Once this has happened it cannot form the meanders that characterise a ‘natural’ river. Much of the course of the river between the site of Iron Gates Lock at Sheffield Park and Ardingly is straight, deeply incised, lacking ecology and passing flood flows extremely quickly and to most damaging effect. The removal of Fletching Mill weir and the lowering of the pound above it will lead to exactly the same effects here.
2008 Consultation - Alternative Solutions
SORT argued that Royal Haskoning’s proposals were completely unsupportable for all the reasons given above. SORT had tacitly supported their original proposal given in their leaflet “Fletching Mill - What are your views?” for riffles to be created to raise the level of the river bed below the weir up to the level of the current weir crest in a smooth slope between the arched road bridge and the weir, adding to this the suggestion that the existing ditch across the site could be re-profiled to pass a greater flow from the bypass channel to the old navigation channel and larger navigation bridge, to alleviate damage to the smaller arch bridge. A possible issue with this latter suggestion was raised at the public consultation meeting in that there were concerns from some quarters as to the archaeological importance of the old mill leat that the ditch crosses. However, SORT’s consultant archaeologist considered that the size of the leat in profile and its original construction should be recorded precisely by taking a section across it as a part of the re-profiling exercise. There was no specific archaeological value in one section of the earthwork itself.
In truth, of course, it would have been best had the Environment Agency completed the works that they planned and began in 2001. That is, manufacture the replacement sluice gates to the correct dimensions, fit them and make the sluice fully operational again.
2008 Consultation - Subsequent correspondence between SORT and the Environment Agency
A letter, containing the information given above, was sent to Environment Agency on 20 October, 2008.
2008 - Pictures
The following pictures were all taken by Bernard Snell on 30 October 2008 between Fletching Mill and Sheffield Park.
August & September 2010 - Demolition
On 30th September 2010 the Environment Agency “External Relations Officer (Committees) Southern Region Communications” issued a press release titled “Collapsed Weir Leads to River Restoration”. This stated that…
‘A weir known to be several hundred years old collapsed without warning in the middle of August, blocking the stream and becoming a hazard for visitors. After an agreement with the local farmer, fishing club, Environment Agency officer Andy Manville was tasked with removing the old structure from the channel and re-using the bricks from the weir to help reduce erosion to the river bank and direct the flow of the river down the centre of the channel.’
Andy said: “The construction process was relatively straightforward, but there are a number of factors to consider – the safety of local people, wildlife habitats, and the cost of maintaining the river in the future. We reused much of the old material, so there was no direct cost to the work. We also left the apron (the stone base below the weir) in place as we felt this would increase the level of water, which would aid the fishing club and create a small cascade to encourage fish passage to all species. Previously the weir prevented the movement of all fish to a large area of upstream habitat. The end result is that the area looks much more inviting and pleasant for local residents. The support we have received from those living nearby, landowners and the fishing club has been amazing.” The Environment Agency’s team of officers have now completed the work and the benefits to local wildlife are already clear.
October 2010 – SORT Response
On 3rd October SORT sent the following email in response to the press-release….
Your e-mailed press release has been passed on to me by Roy Sutton of IWA in my capacity as Chairman of the Sussex Ouse Restoration Trust (SORT).
Firstly, I must put on record how disappointed I am that this piece of news should reach us at SORT by such a circuitous route and after the work has been implemented as 'fait accompli'. As you should be aware, SORT spent a lot of time and effort in reviewing the original proposals for repairs to the weir at Fletching, including the preparation of a Report on your original proposals by Roy Sutton and participation in the consultations culminating in the presentations at Fletching Village Hall in September 2008. We then commented in writing on the sole remaining proposal given at that time and I have kept in touch from time to time since then given the lack of any formal communications from the EA on the matter. The last e-mail I had from Andy Manville dated 23rd April 2010 read as follows:
"Dear Mr Draper
Unfortunately progress has been slow as we have had to focus on other projects within the Agency... We have looked at various options for the site at Fletching
Mill but as yet we haven't made a decision on the way forward. As soon as a preferred option has been agreed we will inform all interested parties."
Perhaps you can see from this why I was so shocked to receive a copy of your press release via a third party.
Secondly, some of the statements and claims made in your press release prompt me to make my own observations or to seek clarification or additional supporting detail. "A weir known to be several hundred years old collapsed without warning in the middle of August, blocking the stream and becoming a hazard for visitors." So far as 1 am aware, the weir at Fletching is (or rather was) on private land with no public access. Could you please support your claim that the collapse of the weir was therefore "a hazard to visitors"? Since the deterioration of the fabric of the weir has been known to the EA since at least early 2008 (hence the consultations on proposals to repair it), it also seems a bit far-fetched to claim that the weir "collapsed without warning".
"After an agreement with the local farmer..." The local tenant farmer is Mr. Derek Lingham. We know from our discussions with him in 2008 that he was vehemently against the grinding-down of the weir and was demanding that it be repaired and kept in situ as it had been for hundreds of years. He valued the weir as the major contributing factor to the regular winter flooding of his water meadows,, together with the increased fertility and wildlife biodiersity that this twice- or thrice-annual inundation brought with it. He was greatly concerned that the proposed removal of the weir would either prevent entirely or at the very least reduce the frequency with which these floods occurred, with a detrimental effect on the meadowland and its increasingly rare habitat. What precisely was the nature of the "agreement with the local farmer", or was this not so much an agreement about the work that was to be undertaken, but simply an agreement to allow access to the site for the workforce? We shall be contacting Mr. Lingham to hear his side of the story in the next few days.
"We also left the apron (the stone base below the weir) in place as we felt this would increase the level of water, which would aid the fishing club and create a small cascade to encourage fish passage to all species. Previously the weir prevented the movement of all fish to a large area of upstream habitat." The weir already had a fish ladder in place to allow the passage of migrating fifa from below the weir to the deep-water reach above. Are the EA claiming that this fish pass was completely ineffective, and if so why had it not been looked at and improved in the past? SORT had a study done on all the fish-passes on the river about eight years ago and whilst some of them were not perfect and could be improved, none were found to be completely ineffective. We should be able to track down a copy of this report if anyone is interested in receiving one. From the photographs supplied, it appears that the attempt at increasing the level of water has failed completely, as in both the before and after images there is very little water depth and a strong enough flow to deter almost all coarse fish species from moving over the weir apron. It is possible that salmonids could travel upstream in the right conditions, but according to Mr. Lingham they used to successfully negotiate the fish ladder each year anyway, at least until the construction of the sump weir at Barcombe Mills. Since that time he has seen no trout jumping at Fletching weir at all.
The major environmental impact of the removal of the weir at Fletching is the destruction of the deepwater reach that existed above the weir, a perfect habitat for a large number of coarse fish, wildfowl and other species. That has gone to be replaced by a shallow stream running in the bottom of a deep cut. Is this what Andy Manville meant by "to consider..... wildlife habitats" ?
"The end result is that the area looks much more inviting and pleasant for local residents. The support we have received from those living nearby, landowners and the fishing club has been amazing." From perusing the photographs, I would say that this is a subjective matter and should not be a statement of fact. Personally, I find a deep-water river reach with abundant wildlife far more inviting and pleasant than a trickle of water in the bottom of a ditch with expanses of muddy banks. I then find the statement about the support received from those living nearby and landowners to be breathtaking in its audacity. There are two riparian landowners at Fletching weir. Mr. Lingham is the tenant farmer to one of them and we know his views on the destruction of the weir. The other is John Wynn of Mill Farm, who owns the west bank. He has always been vehemently against the destruction of thee weir. Here is the content of the e-mail on this subject that he sent to me a couple of days ago when I made contact with him - he was away from home when the work was actually done:
Have been away so have only just received your email. I can confirm that the weir has gone and with it most of the water in the river. What happened was that a couple of months ago the weir gave way from the bottom so that a large volume of water passed under the weir rather than over it. I had a visit from the Environment Agency who in effect said they had no money to be able to repair or replace it and therefore would have to demolish what was left and grind it into hardcore which would remain on the river bed. They also promised to put in some form of fixed barrier so some water would be contained in the river and diverted into the mill pond and mill stream. The first part has been carried out but we are still waiting for the barrier and in consequence there is little water in the river and even less flowing into the former millstream. The whole area now looks very sad.
As you can see, we and the local landowners are devastated by the EAs wilful destruction of the weir, which has only occurred through a systemic failure to maintain the structure properly in the past- a classic example of "a stitch in time saves nine".
"the benefits to local wildlife are already clear." Can you please provide some substantive detail for this claim?
"The redesigned river will save money on future maintenance costs...." Well, at least you come clean in the end and admit that this was really just a cost-saving exercise. It would have been better perhaps if you had been brave enough just to make that statement without dressing it up as a positive environmental improvement.
Only time will tell what impact the removal of this weir has on the speed of water movement in flood conditions and how it will affect the flooding of areas downstream, Uckfield and Lewes. The first winter storms this year could be interesting.
No response to this email has been received.
November 2010 – Fletching Parish Council
Below is an extract from the Fletching Parish Council Minutes of their meeting of 1st November 2010…..
1384. Fletching Mill Weir/Environment Agency: The Chairman welcomed to the meeting the three representatives of the Environment Agency who had responded to a request from the Council to discuss the dismantling of the weir at Fletching Mill.
There followed a detailed debate upon the complete removal in August of the weir at Fletching Weir. The main thrust of the Council was that it had not been consulted concerning the latest works despite an earlier 2008 consultation which promised more consultation prior to works being undertaken to the weir. The Council was also concerned that the complete destruction of the weir had been unnecessary and carried out without warning; particularly as there had been hope that the structure would be refurbished.
Issues raised by landowners and farmers included concern with the lack of flow in the navigation channel, which might well lead to silting; upstream erosion caused by a lower water level and loss of attenuation - there being a perceived increase in flood risk.
The Agency asserted that there would be no increased flood risk; it would keep an eye on erosion and that one stop board would be removed and probably a second.
It was alleged that a ten point letter to the Agency had not been replied to in writing and an undertaking to the effect that a response would be forthcoming was given.
Many differences of opinion were expressed with regard to the detrimental effect to the river arising from the removal of the weir; it was the general view of the meeting that there had been a complete breakdown of communication which had to be resolved.
For their part the Agency representatives undertook to give a written response to the ten points raised by landowners in March 2008 and gave a further undertaking to liaise more closely with the Parish Council and Landowners in the future.
The Chairman thanked all those who had attended the meeting and spoke on the subject.
January 2011 – EA Response to a local resident
The following letter was sent by EA on 19th January 2011to a local resident, who kindly forwarded it to SORT. It is a response to a formal ‘Information Request’ made by the resident (who is a barrister).
Information request; Fletching Mill
Thank you for email and your request for further information regarding the works carried out at Fletching Mill. I would like to take this opportunity to say we are very keen to work with you to resolve any outstanding issues that remain.
Please see below our response to the concerns you raised in your letter dated 5th January 2011. Our response to your comments (in bold) are as follows;
1. Mr Nunn's response of 25 October and earlier phone call failed to answer the vast majority of my information requests. Please can my requests be answered each specifically.
2. Para 2 he states the mill weir was not removed rather it collapsed. I understand that in fact it suffered partial collapse, but certain parts which survived the collapse were then deliberately demolished and removed by the EA. It is the information and considerations around the decision to remove the remaining parts of the weir that I am asking for, since this step appears to be have been done on scant information without consulting a number of interested organisations, including the Sussex Ouse Restoration Trust who have expressed a keen interest and shown considerable expertise relevant to the considerations.
3. Para 2 states that prior to the collapse / demolition works consultation had commenced as to the future of the Weir. I understand that this consultation did at one stage include the Sussex Ouse Restoration Trust, but latterly they had not been consulted or sent the draft CFMP, and the sudden and pre-emptive decision post collapse to demolish the remaining structures most certainly did not consult SORT. Why not?
The Weir failed on the 13th August 2010 a significant part of the structure and supporting river bed was washed away. This left the structure in an unsafe and unsupported state therefore work to remove these parts were undertaken by the Environment Agency. Had the structure been left in its failed condition uncontrolled erosion and potential damage would have been caused to the riverbanks and neighbouring land. These were emergency works, if immediate action had not been taken to make the remains of the weir safe, results could have included flooding, bridge blockage or even damage. Although consultation did take place the Environment Agency has permissive powers so there are no requirements for agreements to be met with landowners. The work carries out to make the structure safe is supported by the Town and Country Planning Act (General Permitted Development) Order 1995. Part 15 A(b).
4. The CFMP policy page 13 refers to "investigate removal of structures to restore rivers and floodplains to a naturally functioning state", and Para 2 of Mr Nunn's response claims certain structures for which removal would be beneficial. The SORT response of 2008 by Roy Sutton and document explaining how weirs held alleviate flooding (copies attached) explain why removal of the weir would not in fact further this objective. Please give full particulars of the appraisal conducted and conclusions reach that removal of the weir structure would further the aim of restoring floodplain to a naturally functioning state. Also, has the SORTs response of 2008 been taken into account in developing the CFMP? Does the EA accept Mr Sutton's comments? If not why not?
Much of the Ouse is "heavily modified" and these modifications include channel straightening and structures such as weirs, locks etc. Restoration of this stretch of river to a more naturally functioning state is policy under the CFMP and is also a mitigation measure under the Water Framework Directive. Full restoration would clearly include re-meandering the river's original platform, which is clearly not feasible in the context of current land use. Achievable aims therefore include localised restoration initiatives, including structure removal and bank work. We consider these localised initiatives contribute to biodiversity and natural river function, and local conservation bodies are in agreement with us on this. Our perspective clearly differs from that of Roy Sutton. With respect to appraisal work, in 2008/9 we undertook consultation on options, which included weir removal, as part of a non-statutory EEA exercise. Consultees included expert ecologists and the conclusion were that the river biodiversity would benefit from weir removal.
5. Para 5 states the ecological appraisal team was consulted, and para 6 claims biodiversity would be improved by dumping rubble in the stream. Please provide full particulars of the appraisal conducted, options considered and evidence taken into account around the consultation of ecological team and belief that biodiversity would be improved.
Waste from the failed/removed weir was reused in situ as an exemption under the Environmental Permitting ( England and Wales ) Regulations 2010, part 1 (4) and referring to Schedule 2. These regulations supersede, incorporate or have effectively transposed those in the question. Internal ecologists have been consulted since original project inception and regularly monitor the Ouse above and below Fletching Mill. Since weir failure/removal, fish catches above the Mill have increased. EA ecologists indicate that the upstream ecology will change from still water ecology more often associated with a lake or pond environment to that of a normal, flowing stream. Greater biodiversity is expected due to the wider range of niches and upstream flow regimes resulting from the failure/removal of the weir.
I have attached the first fisheries memo that was handed out at the parish meeting and both Ecological Reports completed with data from before the weir failed (pre report) and after the weir failed (post report), it is worth noting that for the post report. Analysis and Reporting have yet to sort through the invertebrate samples taken immediately after the weir failed. Further macrophyte, invertebrate and River Habitat Surveys (RHS) will be completed in May 2011 which is the appropriate time of year to carry out these surveys.
With regards to the comments about consultation. Both Analysis and Reporting (Ecological Appraisal) and Fisheries, Recreation and Biodiversity (FRB) have been key members in the project group since inception of the Fletching Mill project. As such, there advice and recommendations have been included in any works that have been progressed. There conclusion that biodiversity (encompassing fisheries) has benefitted is as a result of the environmental evidence (fisheries data) that the ecological reports have concluded. There is no longer an obstruction to all fish species at this site enabling a more diverse and natural community. This evidence is further backed up from anecdotal evidence provided by the local angling club to our team that match day results have shown a more diverse community of fish species caught.
The information is provided subject to the enclosed notices.
I hope the enclosed information is sufficient. If you require any further help please contact me.
External Relations Officer
Kent & East Sussex External Relations
Attached to this letter were…
Comments on this letter….
The letter deals solely with river ecology. It makes no reference to the ecology of the riparian water meadows that have now been drained and whose ecosystem (which has not been surveyed) will be lost. The figures given result from a series of surveys by environmental specialists, but their specialism will, of itself, create a bias.
The final paragraph 'Conclusions' of Jessie Durkota's Survey Report implies that removing the weir gives a river with greater diversity. However, what it does not say is that leaving the (pre-removal) 'lentic' ecology intact increases the overall diversity of the whole river, (ie The greatest diversity would be provided by some sections being lentic and some fast-flowing). It is ironic that the 'Fisheries Summary' identifies lillies as indicative of a degraded channel, yet the lillies in the Royal Military Canal are identified in the citation for that waterway being a SSSI!
Environment Agency and Royal Haskoning, as a first stage in the MORPH (Middle Ouse Restoration of Physical Habitat) project issued a ‘Case Study’ titled….
It was entirely about Fletching Mill, giving a very biased view that created a very sour start to what subsequently became a well-balanced MORPH project.