Fletching Mill
SORT’s comments (marked in red italics) on Environment Agency’s Response

Pevensey Office. Coast Road, Pevensey Bay, East Sussex, BN24 6ND.
Customer services line: 08708 506 506
Email: enquiries@environment-agency.gov.uk
www.environment-agency.gov.uk

Mr R A Draper
Chairman
Sussex Ouse Restoration Trust

Date: 27 November 2008

Dear Mr Draper

Moving towards more sustainable management at Fletching Mill

Thank you for your letter dated the 20th October and for the time you have taken in preparing your detailed comments representing the views of the Sussex Ouse Restoration Trust. We have recorded your views within the consultation record that we have been maintaining throughout the Fletching Mill Feasibility Study and will take all consultee comments into account as part of the decision-making process regarding future management of the river and structures at Fletching Mill.

In the meantime, we felt your detailed submission merits a considered response, given in particular some of the issues and assertions raised. The comments detailed below are referenced to the numbered sections in your letter to enable the corresponding responses to be identified.

With regard to the history of the site (section 1) you state that "the pound above Fletching Mill weir has been at its present level for over three hundred years". This is not technically accurate taking into account the drop in water levels that was experienced following the failure between the sluices failing in 2001 and the installation of temporary works in 2002. [SORT’s statement does not say (or imply) “three hundred continuous years”. The pound has been drawn down for short periods many times (for maintenance of the mill and lock as well as the recent incidents). Short drawdowns do not significantly affect river or riparian ecology. EA now propose a permanent irreversible change.]

Regarding recent events in 2001 (section 2) I can confirm that it was in fact the newly installed replacement gates that were damaged at the time of the "straw bale" collecting at this point rendering them inoperable. Subject to this damage there was no temporary works carried out to re-instate the pounding upstream of the site until 2002. [Fletching could site a rising sector gate supported by corbels spanning from the original lock walls. Rising sector gates cannot be blocked by straw-bales (or other foreseeable debris). Let us hope that EA has fed-back details of this incident to its gate design and specification engineers.]

In reference to consultation leaflet (para 3a), the main purpose of issuing this to key stakeholders in March 2008 was to identify key stakeholder concerns and issues at the outset of the Feasibility Study, in order to inform the option appraisal process rather than to define what options were being proposed. The leaflet therefore stated that "Solutions being considered at this location include: modification of the weir at the head of the by-pass channel and regrading of the by-pass channel". This implies that these were not the only option under consideration as, at this early stage, we were still determining baseline conditions and the range of options for consideration. We accept that our consultation leaflet could have made it clearer that crushing of the weir in situ was an option, although "modification of the weir" could plainly include this outcome. [Had respondents to the consultation been informed immediately the approach had been changed EA would have received earlier feedback, before the public meeting, perhaps in time to have avoided becoming entrenched.]

We received the report prepared by Mr Sutton (para 3b) in April 2008 and agree with the substantive points of fact presented regarding the condition of the weir structure. Points in the report of relevance to the SORTs subsequent position include the following. (Para 1.5) "The Sussex Ouse Restoration Trust proposes to restore the Sussex Ouse to navigation. This report is prepared at their request to advise on options that might assist both navigation restoration and the preservation of historic structures..."(Para 3.2)" Regarding and introducing of riffles [in the by-pass channel] would improve the ecological potential of the present poor environment". With regard to the proposed consideration of diverting the flow from the by-wash channel (termed by the Environment Agency as the mill channel), we can confirm that we have included consideration of this option in our Feasibility Study.

With regard to the public consultation meeting at Fletching Village Hall on 8th September 2008 (para 3c), we agree on the whole with the record of events you describe but would differ on points of fact.

• With respect to the statement that "a radically altered solution" was proposed at the 8th September meeting, see comments above concerning the consultation leaflet. We would also stress that the purpose of the meeting was precisely to present proposals being considered in more detail to consultees to obtain their comments as part of the ongoing consultation process, following the initial consultation leaflet. [It seemed at the meeting that removal of the weir was a foregone conclusion.]
   

• With respect to your and Mr Sutton's assertion at the meeting that the new proposals would damage the ecology of the river, no evidence was provided for this. Ecological improvement is one of the key drivers for this project and our own ecology and biodiversity specialists are fully in support of the proposals. The position taken in your recent letter also differs to Mr Sutton's previous position in this original report (April 2008) relating to the positive . . benefits of introducing riffles (which would be an inherent element of the weir removal regime). [Riffles can provide benefit whether or not the weir is removed. Mr Sutton’s report worked on the basis of the information in the consultation leaflet and he therefore assumed the weir would be retained. He suggested riffles placed downstream of the retained weir, with the channel widened and the bed raised to reduce the fall over the weir to effectively nothing.]
   

• With respect to the assertion that the weir removal would increase flood risk in Uckfield and Lewes, there is no evidence to back this up with respect to either Lewes or Uckfield (see section below on flood risk). ). [Agreed there is no change in flood risk to Uckfield. See comments below on flood risk to Lewes.]
   

• The assertion that the proposed solution is contrary to the Agency's Catchment Flood Management Plan for the Sussex Ouse is incorrect. The proposed CFMP policy for the Middle Ouse is to "Take action to increase the frequency of flooding to deliver benefits locally or elsewhere" This policy is to be delivered at the catchment-scale for Middle Ouse as a result of combined action. We are currently developing our strategic approach to management of the River Ouse in line with this policy and the naturalisation of the river regime at above Fletching Mill is not inconsistent with delivery of this policy, as well as environmental benefits. [The CFMP policy is correctly stated above and we agree with EA that it is the correct policy. What it means is that EA will take action to increase the frequency of flooding in the Middle Ouse such that floodwater is temporarily retained in the Middle Ouse reaches (by spreading over flood meadows and adjacent farmland). The effect of this is that the size of the peak flood in Lewes is reduced, along with damage and risk. Removing Fletching Weir would cause the height of the flood upstream of the former weir to be reduced. So less water is spread over flood meadows. So EA’s proposed solution at Fletching would have the exact opposite effect to that required by EA’s CFMP.]
   

• The assertion that the proposed solution is contrary to the Agency's national policy on the improvement of biodiversity is incorrect. Biodiversity is a key aim of this project though naturalisation of the flow regime upstream of Fletching ! Mill and easement of fish passage. [See comments below under ‘ecology of the river’.]

With respect to comments concerning the ecology of the surrounding land (section 4) as a result of the proposed solution, we feel your assertions significantly exaggerate the risks. The area immediately upstream of Fletching Mill has been a floodplain since far before impoundment took place at the site and will continue to be a floodplain after the weir is removed. It is unreasonable to state that "this land will be permanently drained, destroying its fragile ecosystem" and there is no evidence to suggest this will happen. We have already consulted with Natural England regarding the habitats upstream of the weir and they do not see this as a constraint on our proposals. [Please take a look at the pictures on the web-pages, particularly those of the ox-bows in the flood meadows and the presently flooded tributary ditches. The ecological value of these sites will be entirely lost if they are drained (which is what will happen if the weir is removed). Proof of this outcome is given by inspecting the three former oxbows upstream of Iron Gates lock (midway between Fletching Mill and Sheffield Bridge). The weir at Iron Gates lock was removed many years ago and the upstream water level dropped accordingly. The three formerly waterlogged oxbows are now drained and devoid of ecological value. The National Trust would like to see them re-watered and sought advice from SORT on how water levels might be raised to achieve this.]

With regards the requirement for a "full Environmental Impact Assessment" (section 4), each project the Environment Agency undertakes undergoes a screening process to judge the level of Environmental Impact Assessment (EIA) required, using a risk-based approach above and beyond statutory requirements. The Agency's National Environment Assessment Service has been involved in this project from the outset and the project has been screened as not requiring full statutory EIA. However, we have identified key environmental risks and commissioned a series of specialist surveys as part of our EIA process. [Have the ox-bows and tributary streams been identified in this process? None of the EA personal at the Public Meeting seemed to be aware of them. Perhaps, had they been, a full EIA would have been undertaken. ]

[The statutory indicative threshold and criteria for an EIA are given by "Environmental Impact Assessment-A guide to procedures", (published by DETR) as for "Inland waterway construction, canalisation and flood relief work" (the nearest thing to what EA propose) "The area of works exceeds 1 hectare". "The likelihood of significant impacts is likely to depend primarily on the potential wider impacts on the surrounding hydrology and ecology. EIA is more likely to be required for development of over 2km of canal. The impact of flood relief works is especially dependent on the nature of the location and the potential effects on the surrounding ecology and hydrology. Schemes for which the area of the works would exceed 5 hectares or which are more than 2km in length would normally require EIA". The proposal will affect water levels over more than 2km of river and over more than 5hA of floodmeadow. But the length and area of "direct" works are less than 2km and 5hA. EA will therefore claim (as their letter does) that they are exempt. Were the situation reversed, with SORT reinstating navigation then EA would claim work was being done throughout and an EIA is a legal requirement.]

You will be aware that reducing flood risk (section 5) is a key goal in our Corporate Strategy. Nationally, with limited funding available for flood risk management projects, streamlining the management of individual assets is particularly important to making the best use of available resources. In this case, removing the requirement for re-construction and future maintenance of Fletching Mill weir is inline with this goal. Locally, flood risk is critical to the viability of any project at the waters edge and a detailed computer mathematical model has been built to simulate the effects of weir removal on water levels. Results show that flood risk is only locally affected, with a reduction in water level observable for less than 1 km upstream of the site. Catchment scale management is vital to achieving reduced flood risk in critical and flood prone areas like Lewes. The River Ouse Catchment Flood Management Plan defines and justifies strategic policies for different areas and the area around Fletching Mill is defined by a policy to increase flood risk. Whilst this project will locally reduce flood risk, it is being considered in conjunction with a number of local schemes, including reinstating old meanders cut-off from main river channel through historic navigational improvements. When combined these projects will align with strategic catchment objectives and also bring the river into a more natural ecological state. [This paragraph contains a number of topics:- (i) It starts by stating that finance is one driver for removing the weir. (ii) It then correctly states that this project will ‘locally reduce flood risk’, without directly acknowledging that the project is, therefore, contrary to EA’s own CFMP. (iii) It implies that this does not matter since water level is reduced over only one kilometre and that other ‘catchment scale management’ will make up for it. SORT expects, were anyone else to suggest such a change in water level is minor, EA would send them packing.]

Contrary to your comments concerning the ecology of the river (section 6), our study indicates that the proposed solution will in fact result in greater biodiversity and this is a key driver for the project. The proposals being discussed would restore river connectivity and a more natural flow regime within the river, in line with European legislation (in particular The Water Framework Directive), and the Environment Agency policies on sustainability, river restoration, flood risk management and biodiversity commitments. A report on options at Fletching Mill prepared by the River Restoration Centre (2002) also states that, under a low water regime: "The water flow regime will be much more dynamic than the previous still water ponded regime. The habitat diversity sustained by the new regime should be much greater than previous". With regard to the requirements for a detailed species survey, the need for detailed surveys would routinely be identified as part of ongoing EIA process that would continue through further stages of this project. [There are several issues in this paragraph:- (i) The River Restoration Centre is correct to say that ‘the water flow regime will be much more dynamic…’. That is because the energy of the water in falling through this reach is presently expended in falling over a weir. If the water level is dropped then the same energy must be spent by the water, which it does by moving faster thus overcoming greater bank and bed friction. In a ‘normal’ river, where the bed is close to land level, this creates a naturally sinuous wide course with riffles. However, the Ouse is not a ‘normal’ river. It has been deepened and straightened. The water’s energy in a deep straight channel creates very fast, shallow flow over a narrow bed several metres below ground level. The channel stays incised. It is too deep to start to meander. This type of channel can be seen between Iron Gates Lock and Sheffield Bridge where the course of the river continues to exactly follow the completely artificial course of the navigation after a hundred years of supposed ‘naturalisation’. (ii) The River Restoration Centre says that ‘habitat diversity sustained by the new regime should be much greater than previous…’. It may be that the diversity within a single reach is increased. However, what removal of the weir will do is change the habitat above Fletching to be the same as that between Iron Gates and Sheffield Park so the diversity of the river as a whole is reduced since the unique habitat at Fletching is being removed to be replaced by the same conditions as extend from Iron Gates to Ardingly.]

With respect to comments regarding the effect on fishing (section 7) the fact that there may be barriers to fish movement downstream does not negate the value of improving fish passage at the Mill. Otters are unlikely to be constrained by the proposed solution and are particularly dependent on adequate riparian vegetation, i which will not be affected by the proposed solution. With respect to otters, Sussex * Biodiversity notes that "Structures installed into waterways to control water levels, such as weirs, mills and locks often restrict the movement of this species".

At face value , flood risk and ecology are central to your arguments and we feel that evidence and submissions from flood risk specialists and professional ecologists contradict your points in these areas. With respect to restoration of the Ouse Navigation and preservation of historic structures - issues not mentioned in your submission but clearly at the heart of SORT'S opposition to this scheme - we share your concern about preservation of historic structures but are not in a position to contribute to your aims to restore navigation to the Ouse. [SORT does not ask EA to contribute to its aims. In due course SORT may initiate detailed proposals for restoration of navigation at parts of the Ouse. Such proposals will have to bear scrutiny, not least regarding ecological issues, and EA will have a role in determining their outcome. It seems that there may be prejudice against navigation based on presumptions about its effects. There is a body of research (notably John Eaton’s work) that shows limited navigation can benefit ecological diversity.]

I hope this letter has clarified the points you have raised.

Yours sincerely

Peter Amies
Asset System Management East Sussex Team leader

cc: Ms Joanna Eyquem, Royal Haskoning,
Allison Thorpe, Principle Officer, Recreation, EA Southern Region
Mr John Morgan, Waterways manager, EA Southern Region
Lewes Flood Action Group

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