Pleased to say we have now had a helpful reply, via HOEG, from engineer Jonathan Madden about his proposal. We’ll be responding shortly with some further questions.
We’ve had no reply to our request to the “Hinksey & Osney Environment Group” on 25 January asking for details of their pipeline scheme, so we emailed them again yesterday.
There was an accompanying editorial in the Oxford Times of 26 January 2019.
At the moment the details of the pipeline proposal are not published. Here are some of the things we’d be interested to know about:
- The OFAS scheme is designed to increase flood flow though Oxford by 38,000 litres per second. What is the volume of water the HOEG pump(s) will pump per second?
- What size of pump is assumed for this job? How many?
- Where would the pumps be located?
- Will the pumps be secure against flooding themselves, and how would they be accessed for maintenance in a flood?
- What provision is there for intrinsic pump failure?
- If the pumps are electrically powered, how is the risk of failure of the electricity supply during a flood addressed. Would there be generators raised above any flood level with nearby fuel stores accessible during a flood?
- What is the route, how would pipes be put underground, how would the many services in the ground be navigated?
- Construction and disposal of spoil.
- How is downstream risk to Kennington in particular, and possibly also Abingdon, addressed?
- How were the costings were arrived at – what do they include?
[The suggestion of a second (albeit smaller) pipeline to Farmoor would be a very large project in itself and is so speculative and far removed from the present issue that we are not asking further about that.]
We wrote to the group concerned recently, on 25 January, asking if we may see their engineer’s plans and any other details; we look forward to their reply so we can better understand their proposal.
According to an article in the Oxford Times of 24 January 2019 the pipeline proposal has changed, so the pipeline would now involve “a pumping station at Seacourt, under Botley Road and then along the Hinksey Plain to the Old Abingdon Road.”
That would mean that the start of the pipeline is (wisely) no longer proposed to be at Port Meadow, and that it ends at Redbridge rather than Sandford Lock.
The cost has risen from “around half the cost” [of the Oxford Food Alleviation Scheme presumably – HOEG press release of 18 January] – which would be about £75 million – to £100 million in the press report on 24 January.
More to follow.
The ‘Hinksey & Osney Environment Group’ issued a press release on 18 January 2019 which included:
“The group is also proposing an alternative scheme, drawn up by a local engineer, which will deliver all the flood alleviation benefits for around half the cost and for a greatly reduced environmental impact.
The alternative proposal involves a pumping station at Port Meadow that will divert flood water through an underground pipe to Sandford Lock.
The pipe would safely carry the flood water around areas currently at risk.
Other advantages of this proposal include:
- Flood water can be pumped much faster than is possible when relying only on an open channel. This means Oxford would enjoy greater protection from flooding.
- It uses proven technology and is guaranteed to work.
- Using a second, smaller bore pipe, the pumping station can also be used to supply water to Farmoor reservoir.
- An underground pipe would have no long-term environmental impact.
- The destruction of local nature reserves, thousands of trees in the green belt and valuable flood meadows can all be prevented.”
This raised many questions and we were surprised that the proposal included a pumping station “at Port Meadow” – unlikely to be universally popular.
More to follow.