The ancient meadows and green spaces of West Oxford already function as flood plains: how much will the new scheme add to their existing capacity?
How many houses will be protected by the scheme beyond the protection offered by the existing green spaces and what is the cost per house?
How many Compulsory Purchase Orders in the Green Belt does the revised scheme involve?
You hope to use rail to move some of the 365,000 tonnes of spoil involved in making the subsidiary channel for the newly excavated stream and other earth removals. In the worst case scenario (if rail impossible or the extra road between the South Hinksey compound and the Hinksey sidings it will require turns out not to be feasible) how many lorries would be needed to move this soil and along what routes?
Will the new stream have any effects (e.g. on flow or maintenance) of West Oxford’s existing three streams?
What proportion of the UK’s small remnant of MG4 grassland is represented by the 2 hectares you plan to remove and hope (but can not guarantee) to re-establish? Where are you taking it to?
What will happen to nesting birds and the bats, insects and other creatures that depend on the trees you are cutting down? How long will It take them to come back to the new habitats you plan to create?
You rightly say that it will be ‘many years’ before sapling trees can replace the established trees you will be cutting down, but how many is ‘many years’? How can replacing established trees and vegetation with saplings match existing bio-diversity, let alone enhance it? Does it not take about 25 years for the trees to come to maturity and something upwards of 50 for bio-diversity to be re-established?
You say that ‘over time’ the scheme will increase [the West Oxford area’s] biodiversity? You say the scheme is planned to have a life of 100 years: when abouts in its life do you envisage the ‘net gain’ in bio-diversity as being delivered?
How is the work of your proposed partnership with Earth Trust in providing a ‘long-term green legacy’ and maintenance (coppicing etc) for the new trees and habitats to be funded?
As the EA recognises in its climate crisis plans, we have about a decade to hold emissions below 2 degree warming. Is this the time to be cutting bio-diversity and hoping to replace it in the long term (which we well may not have)?
A scheme for pumping flood water through buried pipes would cut a much smaller swathe through what till now has been a major source of bio-diversity and a wild life corridor for Oxford: you rightly say a pumped scheme would cost energy to switch on and use during floods. But how does the carbon cost of doing that compare with the carbon cost of the amounts of spoil and trees involved up-front in your preferred scheme? In your plan for moving toward zero emissions in 2030, you say that the pumping you already do in flood schemes costs 17,000 tonnes per year, but that you will reduce this by using low carbon concrete for pump buildings, clean energy, electric motors etc, which mitigations would surely apply for a pumped scheme in West Oxford?
Why is two weeks (17th-31st May) for consultation considered enough time for people with busy family lives, (many of whom may have re-started work on the day the consultation was launched) for people to consider the scheme carefully?