ENVIRONMENT AGENCY ACKNOWLEDGE VIABLE ALTERNATIVE TO OXFORD FLOOD SCHEME – BUT USE JUST ONE INFLATED COST-ESTIMATE TO REJECT
ENVIRONMENT Agency (EA) engineers have for the first time, acknowledged a Twin-Pipe Flood and Pump House System is a viable alternative to their controversial Oxford Flood Alleviation Scheme (OFAS). The Inquiry has also revealed that the EA rejected the alternative based solely on just one, overpriced cost estimate, without any specification, and did not go to ‘competitive tendering’.
The Twin-Pipe alternative is one of four currently being considered by a Public Inquiry at the King’s Centre in Osney Mead until December 18. The Inspector is expected to send a report to the Environment Secretary around Spring 2024. Alternative flood scheme proposers, Jonathan Madden and Kevin Larkin, told the Inquiry their scheme had the added benefit of being able to pump flood water away from vulnerable areas in the early stages of a flood, and not wait for a build-up. However, lawyers cross-examining EA engineers this week heard EA representatives admit that they had a “preferred scheme”, and everything else had to dovetail into that. In a reply to a question from the Inquiry Inspector, lawyers for the EA admitted: “It (OFAS) is only possible scheme to deliver the flood alleviation required for Oxford.”
The OFAS depends on the EA acquiring land though nearly 1,000 Compulsory Purchase Orders. For CPOs to be legal, the EA must have considered alternatives which do not require all/as extensive and area of land to be compulsorily purchased. Campaigners to the OFAS say the EA has failed to do that.
Mr Madden, who lives in Woodstock, is an exploration geophysicist, and client representative for marine engineering geophysical projects, whilst Mr Larkin is a practising architect who has designed major projects, including Heathrow Airport’s control tower.
Protestors of the OFAS tried for years to liaise with the EA over their scheme but were met with a brick wall. The EA simply asked one main contractor, VBA, to estimate the cost of the alternative twin-pipe system. Their initial assessment was £86 to106-million, against the proposer’s £22-million estimate. However, Mr Madden said at no time did the EA ask for a detailed ‘specification’ on which to obtain the estimate. He also said VBA was a major project contractor, and were perhaps not experienced at handling small, three-mile-long pipeline projects.
Mr Madden said: "This week, not only have the EA finally acknowledged our proposed alternative – which would avoid desecrating ancient meadowland, save £70 million of tax-payers money and reduce traffic disruption by two years was a ‘viable alternative’ – in cross examination the EA revealed the problem at the very heart of the OFAS.
“They simply rule out anything that did not conform to their ‘preferred option’, and so they did not give the alternatives the due diligence needed to reach the high legal threshold of CPOs.”
Mr Madden told the Inquiry that VBA’s overall estimate, per mile of pipeline, of ca. £30m per mile is 2.5 times that of the equivalent present-day cost of £12m per mile of the Thames Water London ring main, an underground, 2.5m diameter water pipe! He said: "Taking out the VBA’s estimate of the pump house cost of £36m (Hinksey & Osney Environmental Group estimate: ca. £5m), this still makes VBA/EA’s estimate of pipe-laying, across the flat Hinksey Meadows, £20m per mile, as against HOEG’s estimate of £5m per mile! He points out that this is a comparatively small pipeline project, in the very accessible and straightforward meadows environment."
Mr Larkin said the EA’s contractor proposed a pipe-laying methodology that would not be used in practice. They propose a very wide excavated working corridor for the pipes, whereas the alternative proposal is an 8m wide ‘cut and cover’ trench, as per industry norms. This added considerably to the EA’s cost estimate, he explained.
Mr Larkin added: "The EA asked for a cost estimate from VBA for an outline design that has not even reached the detailed design stage. For any project of this nature using public funds, one would expect the EA to ‘competitively tender’ the pumped proposal estimate, or quotation, to a number of independent contractors. If they did this, we estimate the cost would be reduced by a factor of three times or more. The EA’s main argument against the pipe proposal is on cost grounds. However, it hangs on a single estimate from their main contractor, i.e. not subject to tendering, and not on the basis of detailed design. Therefore, as per usual practice, it is far too high."
Mr Madden says opponents of the OFAS hope the Inquiry Chair will specifically order further quotes be obtained on the Twin-Pipe alternative, against clear specifications, so that a full assessment on the alternative’s efficacy and cost can be made. Then, and only then, can the matter of CPOs be considered.
The inquiry continues.
- Further details of the Twin-Pipes and Pump House scheme can be viewed atLatest News (hinkseyandosney.org)
For further information/Interview:
Canon Chris Sugden 07808297043 csugden@ocrpl.org;
(Chair – FHT)
Jonathan Madden jonathan.madden@prussia.globalnet.co.uk
(Alternative Pumping System Designer)
Paul Eddy 07923653781 paul@pauleddy.uk;
(Public Relations Consultant to FHT)
Editor’s Notes:
- On Tuesday 14 Nov (PM session) Phil Raynor for the Environment Agency, in his Evidence in Chief, stated that an optimized twin pipe system could be made to work technically, but he said thetrench for the pipes would have an effect on the flood plain and the meadows. However, he admitted it had not been tested in their modelling.
Clive Carpenter, a Consultant Hydrologist contracted by the Ferry Hinksey Trust, in his evidence to the Inquiry, told the Inspector that what was being presented by the EA was not a fully detailed project, but simply “a concept”.
The Twin-Pipe and Pump House proposal would largely remove the need for CPOs - with the exception of the pump house itself. The current OFAS is said to currently cost £176-million and includes creating a 5km long ‘channel’ which would run from just north of Botley Road, to south of the A423 southern bypass near Kennington, where it would re-join the River Thames. Leading independent ecologists say the dug channel would destroy 13 acres of the rich, rare species of the irreplaceable plant community of Hinksey Meadow. An estimated 4,000 mature trees and miles of hedgerows would also be lost in the West Oxford wildlife corridor and green belt.
The alternative Scheme has a pump house at the head-end to discharge water immediately downstream of Old Abingdon Road. A pair of parallel pipes, of 2-metre internal diameter would run from a pumping site in a small meadow at Seacourt, under the Botley Road and subsequently along the Hinksey Plain to the Old Abingdon Road.
The system has been designed to pump at a maximum flow velocity of 7-metres/second, with a total maximum flow volume of 3.8-million cubic metres per day, for the two pipes combined. This permits controlled flow, from minimum of near zero up to maximum flow, with a rapid system response. Vitally – and in stark comparison to the EA current proposal – pumping can begin during the early stages of a flood, thereby reducing peak water levels relative to OFAS.
The scheme protects ancient meadow by ending the pipeline with a spillway immediately downstream of Old Abingdon Road, making it a viable and cost-efficient alternative to the OFAS’s channel/swale combination. Beyond such spillway it would ideally combine with another alternative filed with the Inquiry (Alternative A3), adding the benefit of controlled pumping in the early stages of a damaging flood to exploit water-flow capacity downstream of the city. The scheme will largely remove the need for CPOs. Only temporary land disturbance will be required, with the exception of the pump house itself.
The alternative pumping system has an outline cost of £22.1 Million. It is within the overall £70-million cost-saving proposals presented by opponents of the OFAS to the Inquiry.