So-called sustainable urban drainage systems (Suds) incorporate measures designed to reduce surface water flooding.
As many as two-thirds of the 55,000 homes flooded in the devastating floods of summer 2007 were hit because conventional sewers and drains could not cope with heavy rainfall. But moves to encourage solutions have been repeatedly delayed, the Committee on Climate Change said.
It warned that the Government plans are significantly weaker than the steps recommended by the Pitt Review into the 2007 floods.
The CCC’s adaptation committee chairman Lord Krebs said the latest climate projections showed the chance of heavy summer rainfall in southern England had been underestimated and could increase five-fold by the 2080s.
In a letter to Environment Secretary Elizabeth Truss, Lord Krebs criticised the revised approach which relies on simply encouraging the use of Suds by creating an “expectation” they will be employed and excludes small-scale developments.
Friends of the Earth climate campaigner Guy Shrubsole said: “The Government needs to stop bowing to profiteering developers and bring in decent safeguards to protect households and businesses from floods.”