Agenda item

(1)       Ms Katie Lewis, Drainage Manager introduced the report, which had originally been intended to focus on the capacity of the highway drainage system. She explained that this report had been expanded to take account of the fact that capacity issues were not the only causes of flooding on the Kent highways. Other issues were the damaged and ageing infrastructure, including ingressive tree roots; damage by third parties, where utility services had laid their services through KCC’s infrastructure; and the very large number of soakways that were now coming very close to the end of their twenty to thirty year life spans.

(2)       The two main capacity issues were connections into the drainage system as a result of the development taking place across the county; and also the number of local residents who were paving over their driveways, leading to more surface water running onto the road instead of draining away through permeable land.  The other issue arose when water had to be discharged into a third party sewer owned by Southern Water or Thames Water.  She said that KCC had no power to require them to increase the capacity of their water drainage system. Consequently, the only alternative (and usually costly) option was to divert water elsewhere. The most cost effective option was to build up the capacity of the highway by, for example, raising kerbs or by erecting permanent flood warning signs.

(3)       Ms Lewis said that land drainage had been a particular problem during the recent winter. Historically, KCC had tended to be over-lenient. A more robust approach was now being adopted.  Although KCC would always seek to work with the landowners, it was now becoming increasingly necessary to use Highway Authority powers by taking enforcement action or by undertaking the work themselves and recharging.

(4)       A one-off additional sum of £3m had been invested by KCC for work on drainage improvement schemes as well as 200 – 300 minor repairs, additional to the work that the County would normally undertake.  Whilst this was good news, it should be born in mind that there had been some 3.5k drainage enquiries which would require investment.

(5)       Mr Lewin referred to a very recent flash flooding event in Swale, Gravesham and Dartford. He suggested that the Kent Planning Officers Group could discuss the entire question of flooding arising out of short term causes in terms of design of residential and commercial development.

(6)        Ms Lewis replied by saying that the Severe Weather Plan was in the process of being re-written to respond to flash flooding occurrences.  It had been very fortunate on this occasion that senior officers had been available to assist.  The follow up discussions were considering the causes in greater depth as well as how to improve liaison arrangements for a rapid response. This discussion would involve Southern Water, the EA and the Emergency Planning Team.  In terms of planning development, much consideration was being given to sustainable drainage.  KCC would soon be in a position to require developers to have their drainage schemes approved. This would help to alleviate the current problems.

(7)       Mr Harwood said that there was a widely held view (which had been particularly evident during the recent flash flooding event) that the creation of dropped kerbs enabled water to follow gravity and seep into people’s houses.  Although dropping kerbs might seem like a relatively minor change, more diligence would be needed to ensure that their design did not produce this result.

(8)       The Chairman expressed concern that many flood warning signs were too small and flimsy to be effective and put the view forward that they should be resistant to the effects of heavy winds.

(9)       Mr Vickery-Jones said that Ashford BC had undertaken a lot of work on retaining water on site, so that it did not discharge anywhere near the natural flow. This might be worthy of more general consideration. He added that there were occasions when what appeared to be a question of lack of capacity actually turned out to a matter requiring minor adjustments to the layout of pipes. This had been the case at the Street Roundabout in Herne Bay.

(10)     Dr Eddy asked what financial arrangements were being made for the repair of those parts of the infrastructure for which KCC had responsibility. He then alluded to the work of the Select Committee which had looked into the 2000 floods. It had expressed strong concern that farmers were ploughing up and down a slope rather than across it, increasing run-off in terms of amount and quality of water.     

(11)     Ms Lewis replied that the process for improving drainage was that an inquiry from the public would be followed a check for defects and the cleansing of the system.  If a defect was found, the site would be risk assessed. The outcome of the risk assessment would determine where the defect was placed in the priority list.  The current budget for repairing drainage systems was £4.5m. The current state of the network meant that KCC had to be more reactive in its approach.  KCC’s approach to run off as a result of farming activities was to write with an explanation that they were causing water to drain onto the highway and that they needed to stop. Farmers were invariably happy to change their practice once its consequences had been drawn to their attention.  The next step was to work with the NFU to publicise the problem to a greater extent and help keep the highway safe. 

(12)     Mr Vye said that he had recently attended a meeting of the Little Stour and Nailbourne River Management Group who had provided him with details where they considered that failures in highway drainage had contributed to the winter flooding events.  He asked for reassurance that highways drainage was being considered by the numerous multi-agency technical groups. He also asked for the Committee to receive regular highways drainage updates so that it could be reassured that as much as possible was being done to ensure that this was not a contributory factor to flooding events in the future.  Ms Lewis replied that she would be happy to provide such update report. She confirmed that representatives from her team attended many of the meetings and worked closely with the EA, IDBs and others.

(13)     In response to a question from the Chairman, Mr Tant confirmed that KCC did have enforcement powers, outside of IDB Districts, to ensure that drainage systems were unblocked. It could not, however, carry out the work itself (as it would have been able to do if it were a Unitary Authority).  In Hildenborough, these powers rested with the Upper Medway IDB. KCC would only be able to use enforcement powers at the point where internal drainage problems were actually causing flooding.

(14)     Mrs Brown said that Yalding PC had worked closely with Ms Lewis’ Team. She asked whether it would be helpful if a representative of the Parish Councils in each area were to identify highways drainage problems and report them to the Team. Ms Lewis replied that this would beneficial initiative, particularly in respect of minor roads.  She agreed with the Chairman that the most effective way to do this would be through liaison with the Highways Stewards.    

(15)     RESOLVED to note the need for the current level of investment in highway drainage infrastructure to be maintained and potentially increased in the future.