OFAS – clarifications and explanations

We’re aware that there are some misapprehensions around about the Oxford Flood Alleviation Scheme (OFAS). The items that follow aim to clarify some of these points. Where necessary we have sought answers from the Environment Agency to be sure our facts are as accurate as possible.  We’ll be adding to these points, so check back.

See also a later post on OFAS and development

And posts on gravel mining: Gravel mining – Be careful what you wish for and An Oxfordshire gravel mine, 2018

#1 Willow Walk

Misapprehension

“The proposed 60 metre bridge over the ‘channel’ in Willow Walk will destroy over one third of the Walk.”

Fact

The new bridge will continue from the existing Willow Walk track, just raised slightly higher, and will span 19 metres.

It is designed to take existing vehicles and future maintenance vehicles. It will meet cycleway and British Horse Society standards and be built for a 100-year life span.

Thirteen individual large trees (12 white willows and one ash) and part of two groups of smaller trees will be felled to install the new bridge over the new channel. Willow Walk is about 400m long and a stretch 170m long will be cleared in the middle of it. Once construction is complete 20 white willows (10 on each side of the path) will be planted to reinstate the avenue of trees.

#2 Monks Causeway

(called North Hinksey Causeway in the planning documents)

Misapprehension

“Monks’ Causeway to the Fishes will be no more.”

Fact

Both the formal public right of way (North Hinksey Causeway or Monks Causeway) and the informal right of way will be maintained near the Fishes pub. New footbridges will be installed on both to allow access across the new channel.

See Planning Statement: 4.3.3 Recreation and public access.

#3 Transport of excavated material

Misapprehension

“100,000 tons of gravel are planned for extraction and removal along the single track entry point for cyclists, pedestrians and cars for the rugby, archery and tennis clubs through North Hinksey Village. At 25 tons a truck that is 8000 journeys there and back.”

Fact

There are no plans to transport gravel or any other excavated material through North Hinksey village.

#4 Seacourt Stream

Misapprehension 

“The Seacourt Stream will be damaged as the new ‘channel’ takes the flow away. It will have the potential to become a weed choked and rat infested ditch running behind gardens and the garden of the Fishes pub.”

OFA Comment

The published map is, unfortunately, unclear. It makes it look as if what’s said above is indeed the case.

Correct version

The existing Seacourt Stream as it runs behind the gardens along North Hinksey Village and behind the Fishes will remain the main channel, there will be no change under normal conditions.

The new channel below Willow Walk is not a new first-stage channel, it is a flood relief channel (sometimes known as a swale) which will only come into play during a flood: thus it acts exactly like a second-stage channel for the Seacourt Stream but at a distance from it. The swale is raised compared to the Seacourt Stream so water will only enter the swale when levels get high in a flood. 

The Bulstake Stream is higher than the new swale, so there will be some back-flow from that stream into the swale, reaching about as far as Willow Walk (depending on conditions).

Sketch map to follow.

#5 Trees along North Hinksey Lane

“The Botley Road warehouses were allowed because of the tree cover to the view from North Hinksey Lane. These trees will now be removed.”

OFA Comment

We don’t know the planning history so can’t comment on that. 

As far as the present scheme is concerned it is true that the trees on the left bank (i.e. left as you go downstream) of Seacourt Stream in Hinksey Meadow would be removed – that’s in order to take as little of that meadow, with its special MG4 grassland, as possible, while still allowing a two-stage channel for flood relief. There’s been a lot of discussion about this and it seems the best compromise.

On the other hand the trees on the right bank of Seacourt Stream, beside North Hinksey Lane, will not be removed. 

In addition, new trees will be planted along the field boundary by the warehouses – and in the old paddock by the stone arch bridge on Willow Walk.

#6 Dredging 

“Please dredge and clear the rivers and streams which have not been dredged for 40 years”

OFA comment

Whilst dredging can be of some small benefit during normal flows, a river channel is simply not large enough to contain the high flows associated with extreme floods, even if it has been dredged. Dredging gives the impression that something useful’s being done but the reality is that it’d be largely fruitless here and certainly not enough to significantly reduce flooding from a major flood. Dredging’s not without its downsides either – for example, and not surprisingly, it seriously damages riverine ecosystems, especially when done repeatedly.

Dredging the Thames would not significantly reduce flood risk to Oxford. It’s also worth noting that surveying has shown that the River Thames bed is largely stable. Areas dredged deeper would soon silt up again. 

The low-gradient, slow-flowing, braided watercourses of the Oxford flood plain are particularly prone to silt up again quickly after dredging. Dredging would have to be done frequently to do anything at all and even then it would not answer. If it would we’d be all for it, but it won’t.

There are a few specific locations, mainly associated with bridges and culverts, where local silting does need to be dealt with (see #7 below).

#7 Flood plain outflow

“Please … unblock the outflow from the flood plain by the old Abingdon road”

OFA comment

We have been working for over 10 years to achieve just that. We have had considerable success – a new channel and weir at Towle’s Mill, large new culverts under the railway access road at Redbridge, removal of a redundant level crossing bridge, improvements at Munday’s bridge under the railway in Kennington, and clearance of  blocked culverts under the railway at Coldharbour. Certainly these together must have helped in low level flooding – but more is still needed for bigger floods. Climate change predictions suggest these will be more likely in future. 

OFAS in fact provides just such further measures. As a preliminary, a new culvert was installed (taking advantage of the line being closed anyway) under the mainline railway in 2016 – this will be brought into use as an integral part of OFAS. Still to come, OFAS proposes new large culverts under the southern bypass to pull water through the floodplain; the channel banks of Hinksey Drain will be widened right up to Munday’s bridge to increase capacity, and the channel under the bridge itself will be further cleared.

Together these will greatly improve the outflow from the flood plain.

#8 Trees

“The scheme will destroy up to 4000 trees, a fact hidden by the reference in the proposal to ‘groups of trees’ being removed”

We have consulted the EA on this.

The short answer is that the tree-planting proposal results in more woodland within the scheme after completion than at present.

The long answer is here.

Edit, 6 December 2018: there is now an update on trees and OFAS here.

#9 Two stage channel

Misapprehension

“The two stage channel makes very little difference and there are better options. “

OFA response

Modelling of the scheme, with the two stage channel south of Botley Rd down to Abingdon Rd bridge removed, was undertaken by the EA. This appears as Appendix Q in the planning documents. This shows that without the two stage channel, whilst water levels are reduced from the current conditions they do not reduce as much as with the two stage channel which helps improve flow through the flood plain. Without the two stage channel the levels could still cause flooding in Osney Mead, Osney Island, Earl and Duke St and in the area of offices just west of Seacourt Street (the Minns estate). In the scenario without the two stage channel water levels south of the Devil’s Backbone (footpath to South Hinksey) are lower than with the two stage channel due to the redistribution of flows, with more water passing down the River Thames and increasing flood risk in the New Hinksey area. The alternatives which have been suggested – putting more water into the Seacourt Stream where it leaves the Thames would add water to the area where flooding is happening and would make the situation worse. The option of more culverts under the Botley Rd would potentially help move water from the north side of the road into Hinksey Meadow and would reduce the scale of the channel modifications near the Minns Industrial Estate however this would not be as cost effective as the currently proposed scheme and would not reduce levels downstream of Willow Walk.

OFA believes the two stage channel is required for the scheme to work.

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Seacourt P&R expansion is, quite simply, not necessary (including 4 Dec parking data)

It’s easy to get lost in the long and complicated arguments over flooding and planning objections.

But one thing stands out, very, very clear, and very, very important:

There is no need to increase capacity at Seacourt P&R. Oxford has more than enough parking, including enough park and ride.

This is despite the opening of the new Westgate shopping area. If the parking isn’t needed then why does the Council want to spend over £4 million of your, public, money on it? Never mind that it will sit largely unused, and be subject to flooding, and expensive pumping out, maintenance and repair. No, we don’t understand it either.

We looked at online data two days ago, Monday 4 December, 3 weeks before Christmas. At the busiest time, 2pm, there were over 2,700 empty spaces, many in park and rides. Seacourt and nearby Redbridge had 538 empty spaces between them.

Click table to enlarge.


See also our letter to the Oxford Times

For more detail look at these reports:

minerva economics report

minerva further economics report

Westgate Transport Assessment Evidence

Objecting to Seacourt P&R extension – our latest comments

 

We remain strongly opposed to the planning application by Oxford City Council to extend its Seacourt Park and Ride into Oxford’s vital flood plain. There has been a nibble, nibble attrition of the flood plain over many years leading to worse flooding. That the City Council should itself be seeking to extend a car park into the flood plain that protects our city is quite extraordinary.

Here are our latest comments:

OFA comments on FRA Nov 2017 Final

OFA comment on PS Addendum Nov 2017 Final

Redbridge vs. Seacourt P&R from south + Maps

Letter to EA 30 November 2017_final

Lime stabilization considerations Nov17

Seacourt P&R in the Oxford Mail; smart signs, plus risk to life

This article in the Oxford Mail talks about the possibility of  ‘smart signs’ – electronic boards – on the ring road, to alert drivers to where there are empty park and ride spaces around Oxford. This could obviate the (claimed) need to increase the number of spaces at Seacourt, instead pointing drivers to (say) nearby Redbridge. According to an earlier report in the Oxford Mail there is apparently so much spare capacity at Redbridge that the City Council proposes to remove 270 parking spaces, and is quoted in the newspaper as saying that the loss of these spaces would be ‘marginal’.

It seems to us to be inconsistent for the City Council to argue that removing 270 spaces at Redbridge is perfectly ok, while at the same time arguing a burning need to build new spaces at Seacourt – in the floodplain, on Green Belt land, contrary to local and national planning guidance and, as far as the present application goes, creating a potential risk to life (see towards the end of the first newspaper article and our previous post). Never mind the cost, which has already risen from about £2million to over £4 million.

 

Another letter about Seacourt P&R

Our letter published in the Oxford Times, 29 December 2016

We wrote recently about Oxford City Council’s proposal to extend the Seacourt Park & Ride into the flood plain, providing 658 extra parking spaces.

Now we read that the very same council wishes to abolish 270 parking spaces at Redbridge in order to develop a recycling facility. The core argument put forward by the City Council to justify their proposal at Seacourt is that extra car parking is so badly needed that it should be allowed even though the expansion site is in Green Belt and functional floodplain, and despite the fact that it is clearly contrary to national planning guidance and could put vehicles and people at risk during a flood. The Redbridge plans now make nonsense of the special case being advanced for Seacourt.

If that is not enough, the budget for construction of an extension at Seacourt has recently doubled from about £2 million to £4.1 million. The City Council Executive Board papers for 15 December 2016 show projected net revenue from the Seacourt Park & Ride extension of £160,000 a year, and this relies on an increase in parking charges from £2 to £3 possibly starting in autumn 2017.

At this rate the investment would take more than 25 years to pay back. If this figure assumes that the car park remains fully operational and doesn’t ever flood, when in reality it will do so virtually every year causing closure and expensive maintenance, the payback time will be even longer than 25 years.

We are discussing our concerns with the City Council as we believe that their proposal is ill-conceived and unjustifiable and that it should be abandoned before any more money is spent.

Seacourt P&R planning application vs. proposals for Redbridge P&R – comment

We have made further comments (our fourth) on the Seacourt P&R planning application to the Planning Officer today, 19 December 2016:

Planning Application 16/02745/CT3

We wrote to you earlier with regard to the validity of the so called ‘sequential test’ carried out for the Seacourt P&R extension. In addition to our previous argument about the existence of an option of negotiating with the landlord to erect decking on the current site, we have further grounds for objection to the ‘sequential test’.

The City Council Executive Board papers for 15 December 2016 include proposals for removing 270 parking spaces at Redbridge to accommodate a new waste transfer facility. It appears there is excess capacity at Redbridge P&R. The analysis of occupancy of Redbridge and Seacourt P&Rs included in the Executive Board papers, show that there is existing spare capacity at Redbridge, and but for the planned waste facility this could relieve Seacourt during the week. There is also capacity at both car parks sufficient to adsorb expected increases in weekend traffic once the Westend development completes.

The Planning Statement for the Seacourt extention makes no mention of the surplus capacity available at Redbridge. The review of Redbridge in the ‘sequential test’ simple says that there is limited scope to ‘expand’ Redbridge. This is deeply misleading. There is clearly scope to redirect surplus traffic from Seacourt to Redbridge, which might be achieved at no cost simply by use of differential pricing – i.e. making Seacourt more expensive. In the Seacourt application we’re told Seacourt has to expand because there isn’t an option at Redbridge. But the Redbridge proposal is using the possible expansion of Seacourt to justify closing parts of Redbridge. So the need to expand Seacourt is at least in part being created by the Council’s wish to re-purpose part of the Redbridge site. This is clearly an unacceptable justification for the Seacourt extending into the floodplain on Green Belt land.

Given the existence of sufficient capacity to deal with any increased weekend traffic related to the Westend, the arguments for the extension, contained in 3.20 of the Planning Statement, appear extremely general. Is this really the best justification the Council can offer for breaching its own core strategy, national policy on Green Belt, and guidance on development in the floodplain? The justification for this move appears to rely wholly on longer term projections about potential increases in traffic resulting from a growth in the city and county during the next 15 years. Such needs should be addressed through a strategic planning process.

We understand that the Council has to increasingly rely on the revenue it earns, and perhaps the real, unstated reason why this proposal has come forward is financial. But even this doesn’t make sense. The capital cost has now doubled from the original budget to £4.1m. Extra income from the extension, assuming rates increase from £2 to £3 a day, is projected at £160,000 a year according to the Executive Board papers. Even assuming this revenue is achievable the investment would take more than 26 years to pay back, and that is without discounting for the cost of capital. If, as we believe is likely, the site floods regularly, has to be closed part of the year, and faces significant maintenance costs, the payback period will be much longer.

This scheme is a nonsense and should not proceed.

Thames Regional Flood & Coastal Committee visit Oxford

The Thames Regional Flood & Coastal Committee (RFCC) met in Oxford yesterday. Following the meeting, members visited sites in Oxford related to OFAS. Members of our steering group were on hand to welcome them and, with staff from the Environment Agency, showed the visitors some of the problems which need to be surmounted to alleviate Oxford’s recurrent flooding.

Flooding which, unchecked, is likely to threaten further the proper functioning, and the reputation, of the city in the future if (as a consensus of scientists predicts) climate change makes extreme weather more common. OFAS offers the only practicable way towards reducing this all too real danger in time.

2 Oxford FAS meetings

IMG_6013cropfloodplain2008

Oxford floodplain in 2008, a little water in the fields

27 October 2014
Two meetings.
First: we are represented on the Oxford Flood Alleviation Scheme (Oxford FAS) (‘the Scheme’) Sponsorship Group – the committee backing these proposals. A few points:
•    There is a long, rigorous assessment procedure to be gone through; it’s up to timetable.
•    The economic case stacks up.
•    The Scheme cannot risk making things worse downstream: this is key and must be established.  [FWIW our view has long been that a successful scheme must keep water moving, getting it away earlier and not allowing it to build up enough to flood roads and buildings. But this will not send MORE water downstream, it doesn’t ‘generate new water’, it will only alter the time course. (Note that our flood plain will still flood, just not quite so deep.) That seems to make sense, but more rigorous evidence will rightly be required re any possible downstream effects.]
•    The Scheme will enhance the natural environment.
•    Public access will be better (cycle paths, footpaths).
•    Climate change projections, if they come to pass, would make things very much worse than now, making the Scheme in our view even more imperative.
•    The Scheme will have as an integral part measures (such as property-level protection) to help local areas/properties that are not ‘saved’ by the removal of existing pinch-points and the more efficient water flow in a redesigned watercourse. (NB that is not a guarantee that every property will be protected.)

Our support for the Scheme is now stronger than ever. But we know others have doubts or other ideas – if you want to discuss these please do come to our APM on November 13th (see below, 16 Oct). We will be there (of course!) and so will the EA.

Second: three of us met with Richard Harding of the EA Project Team for the Scheme. John Mastroddi (of OFA) presented the data from his own observations during the 2013/14 floods: these show that, as in the 1947 and other floods, that there is a 60cm difference in flood levels across the railway near Kennington. This is therefore the serious pinch-point and overcoming it is essential. John also presented his novel ideas about what might be done at Sandford-on-Thames as part of the Scheme: his ideas will now be considered during the assessment process.

Pinchpoints

3 January 2013

River levels are still about 1m above normal in the west Oxford floodplain. This emphasises the difficulty water has in getting away from our area. It  has to get under the main-line railway to reach the Thames. There are three bridges under the railway downstream of the Botley Road.

We have been campaigning about the furthest downstream, Munday’s bridge, a 60ft bridge at Kennington, for some years. We are eagerly awaiting the start of a Thames Water project to greatly improve the flow of water under the bridge. There have been delays, but we are optimistic that the work will go ahead reasonably soon. This should reduce flooding of property and the railway line.

Annual Public Meeting of the Oxford Area Flood Partnership (OAFP)

27 October 2010

Annual Public Meeting of the Oxford Area Flood Partnership (OAFP). (This is not OFA.)

We attended and asked about:

  • Lamarsh Road as a flood route (we presented our report – October 2010)
  • The railway track at Redbridge
  • Munday’s underbridge at Redbridge
  • Why OAFP meetings are held in camera
  • Work that we have been pushing for on Osney Island.

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