Sir – Around the Millennium, under an anti-environmental Labour government, the Environment Agency blew £110m building the “Jubilee River”, taking floodwater from above Maidenhead to below Eton. Residents downriver say it moved floods downstream.

In 2001, Black & Veatch proposed various relief options for Oxford. The EA, Oxford Flood Alliance and others all want a “western conveyance channel”. Costs, estimated at £100m in 2005, have risen to £160m now. But on floodplains only part of the flood water uses channels. The rest spreads, saturates the plain and takes longer to flow along its breadth.

Dick Wolff (Letters, January 23) asks if medieval deforestation of West Oxfordshire increased flooding. Possibly, but Wychwood was far bigger than now until the mid-19th century, when much of it was cleared for farmland. Did that increase flooding of the Evenlode, Windrush and Isis?

Binsey, Botley, Hinksey, Osney and Rewley are old islands inhabited since the Middle Ages. But Victorian and later speculators built recklessly along Abingdon and Botley roads that kept flooding. David Horner (Letters, January 23) mentions floods in 1852. They recurred in 1875, 1912, and increasingly now as our climate changes. Building Osney Mead industrial estate and Botley Road superstores sealed another 70 acres of floodland under concrete and asphalt. And Botley Road is effectively a dam across the floodplain.

Actuaries know many floodplain buildings are bad risks, but Defra wants insurers to continue covering them. Flood defences and state intervention in insurance are permanent financial liabilities. Defra wants our good money thrown after bad. Defra admits some coastal defences are futile and has returned some coastland to salt marsh. It ought to admit some inland flood defence is irrational and misguided.

Compensate New Botley homes and businesses to move to safer ground. Put enough culverts under Botley Road. Work with nature. Clear the land. Let it flood.

Hugh Jaeger, Oxford