For those who have already been flooded this winter, their future losses will be compounded by a lack of affordable height information. Ahead of privatisation, the Ordnance Survey has long sought to put profits ahead of public service by selling detailed information to insurance companies, while providing the public with wholly inadequate 5m contouring. Many continental maps show 2.5m intermediate contours in flatter areas. Belgium has a 1:10,000 series contoured to 1.25m intervals in some areas only costing €6.50 a sheet, while the Brandenburg state survey in Germany has printed even cheaper 10k maps with 0.25m intermediate contours in exceptional places, and spot heights and weirs to within one 10th of a metre. Compare this with the eye-watering prices for buying extrapolated digital elevation data to produce more detailed contouring from the Ordnance Survey, so that most researchers use Lidar topographic imaging data, if they can.
David Nowell
Fellow of the Geological Society, New Barnet, Hertfordshire
• Do local authorities still have emergency planning services (once called civil defence)? Or have these too been sacrificed by politicians, aware of the cost of everything and value of nothing?
Rod Warrington
Chester
More letters on the UK floods
• Time to get real about the UK’s flood defences
• Rewild the landscape to absorb storm waters
• Common sense on flood prevention is being swept aside
• Tories’ leaky policies on flooding leave us unprepared
• Floating structures go with the flow
• Join the debate – email guardian.letters@theguardian.com
