FLOOD campaigners say they are extremely concerned about plans for hundreds of homes around Morpeth.
Several major applications have been proposed for development on all sides of the town in recent months, which could see well in excess of 1,000 new homes being built.
However, the Morpeth Flood Action Group (MFAG) is worried that they would leave the town at greater risk of flooding from surface water and burns.
And it is planning to write to the Environment Agency setting out the concerns.
Chairman Alan Bell said: “We are not against reasonable developments that are sensitive to the environment in which they lie. However, we are concerned the combined effects of approximately 1,700 new dwellings will have a serious impact on the town.
“This is due to the fact that these developments are all planned to be built on higher ground surrounding Morpeth. Their drains and sewers will drain into a number of burns that have already been the cause of severe flooding in several communities over recent years.”
The group says proposed retention ponds, known as Sustainable Drainage Systems (SuDS), are relatively untested in the UK and it is difficult to predict how they would perform over the lifetime of developments. Members also fear that there is no clarity over maintenance responsibility for the ponds and silt could build up, reducing their capacity and leading to ineffective protection.
There is also concern about how run-off levels are calculated and the group has warned that in extreme weather such systems could exacerbate flooding problems.
Mr Bell said: “We worry about the scenario where the Environment Agency and the council have imposed for example a one in 100 plus climate change on all these developments. If we get a storm that exceeds those design criteria Morpeth would be worse off than it is today in the catchments of the burns because of the differing land use.
“It would be like a dam bursting as all the retention ponds would be overwhelmed simultaneously, rather than the phasing which occurs today.”
He said the group is also angry that opportunities for development on greenfield sites to actually reduce flood risk in the town are not being taken.
He added: “It is cumulative effect of these developments and their reliance on a fairly untested and ill-defined technology which really concerns the members of MFAG and the many residents that support the group.”