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Flooding: Lack of maintenance
It is as essential for landowners to maintain their infrastructure as it is for public and private bodies. This is frequently not the case. Whilst decoration and landscaping may be well maintained, gutters, down pipes and gullies (commonly known as 'drains'), taking rainfall are frequently overlooked.
Drainage mitigation measures
Gullies should regularly be cleared of accumulated debris and leaves, and not left until ponding appears. In a severe storm the small capacity of a domestic gully could be the difference between water entering a property or not.
Gutters and down pipes should similarly be cleared on a routine basis particularly where the connection to the storm sewer is via a closed connection. This will enable the rainfall that is harvested to be carried to a sewer as opposed to contributing to flooding around a property. This is particularly important with large roof areas such as terraced properties or large industrial buildings.
It is wise to test domestic drains from time to time. This could be done by tipping several buckets of water, preferably rainwater, down the gully to check that it flows away swiftly. If this is not the case cleaning or further investigation may be necessary.
Remember that all drainage has limited capacity and increasing the area that drains into it can put it under considerable strain. Traditional paving of small areas will have minimal effect however the current fashion for pressed concrete drives or tarmacing of large areas stops the natural drainage of rainfall into the ground. This puts a strain on domestic drains particularly if it is combined with building extensions or conservatories. It also affects the environment by preventing flows going into groundwater which ultimately support the lower level flows in rivers and brooks. Paving of drives with impermeable paving, concrete, tarmac etc now require planning consent.
Ditches and other watercourses the problem
Watercourses are in danger of being seen as part of the garden landscape and not as flood risks. It is only recently that some landowners have become more aware that there are flood risks associated with living with watercourses and a number of publications have been produced primarily following the 'Easter Floods'.
The types of problems encountered are typically structures crossing the watercourse and restrictions, man made or natural, on the watercourse. One of the worst examples of this encountered was a channel that was nominally a metre wide restricted to about 300 mm wide in an attempt to stop bank erosion. The resulting channel had insufficient capacity and blocked more readily with small debris that might otherwise have washed through.
The same problem is true of fencing across a watercourse that blocks, when flow levels rise, with the natural and domestic debris that is washed in by the high water levels. Fallen tree branches etc can have the same effect.
Ditches and other watercourses mitigation measures
Land owners must not construct bridges, fences or other permanent structures across watercourses nor should they restrict the flow capacity by constructing erosion protection within the channel. Such developments require consent under the Land Drainage Act anyway. If such work is proposed appropriate advice must be sought first and consent applied for. Temporary crossings, such as wheelbarrow bridges, must be removed after use. Nothing should be stored on the banks in such a place or way that it may be washed away or fall in.
Watercourses must not be used to dispose of debris, even seemingly innocuous materials such as grass cuttings. Such debris may combine with wind blown debris, twigs etc to cause blockage of grills and thus a flooding incident.
In addition to looking after their own watercourses members of the public should report blockages to the relevant land owning departments where public space is concerned. Most sites, playing fields, facilities etc. have sign boards with emergency numbers where problems can be reported and a list of useful numbers is appended to this report.