Minutes:
(1) Mr Nick Mills from Southern Water gave a presentation. The slides can be viewed on the KCC website page for this meeting.
(2) Mr Mills began his presentation by saying that the Environment Act, which had the full support of Southern Water and the Water Industry as a whole required demonstrable improvements in the sewerage systems together with progressive reductions in the harm caused by untreated sewage discharges. Customers wanted to see a reduction in the use of Storm Overflows and the rise in global temperatures increased the urgency to address this issue. Currently, far too much surface water was getting into the combined sewers and the intensity (rather than the amount) of summer rainfall had become far worse since the 1970s.
(3) Mr Mills referred to the statement by the CEO of Southern Water on its website, which made clear that the time for action was “now”. The target set by the company was to reduce storm overflows by 80% by 2030. This could only be achieved by looking at the entire water system holistically rather than by focussing purely on “end of pipe” solutions. This would entail establishing stronger partnerships, the prioritisation of sustainable catchment and nature-based solutions.
(4) The aim of the Storm Overflow Task Force, which Mr Mills headed was to demonstrate the principles in 5 pathfinder catchments (3 of which were in Swalecliffe, Margate and Deal) over the next 2 years in order to build a regional plan for implementation between now and 2030 which would take full account of scale, cost, difficulty of delivery and public engagement. It was also vital to maintain high standards of transparency whilst improving the accuracy of the Beachbuoy service and the user experience.
(5) Mr Mills moved on to consider the nature of storm overflows. He said that they could be 95% rainwater. Combined sewer systems were a legacy from the Victorian era when they had been built to resolve health issues such as cholera. They were often overwhelmed during heavy rainfall. Surface water levels needed to be reduced at source in order to mitigate storm overflows and flooding risk. The main sources of surface water were roof and road run off, which needed to be removed or attenuated.
(6) Mr Mills then said that there were three main types of intervention to reduce the risk of flooding and storm overflow use. The first of these was “Upstream source control” (meaning the removal and slowing of the rainwater flow). Examples of this were: rainwater harvesting, permeable paving, green roofs, soakaways (including tree pits), rain gardens (swales) and planters.
(7) The second type of intervention was entitled “System optimisation” (making better use of the existing infrastructure). This involved optimisation (tweaking of connected systems and interfaces), different mechanical and electrical equipment (e.g., pumps), improvements in pumping station and storm tank use and control, and smart network control with increased digitalisation. Mr Mills said that the cost of sensors had decreased which afforded an opportunity to modernise the system. Southern Water was also considering the examples of global leaders in this field such as the USA and the Netherlands.
(8) The third type of intervention was the enlargement of infrastructure by building larger sewers, tanks and treatment works. Although this option could be very effective, Mr Mills said that the first two types of intervention were more sustainable both from an environmental and economic perspective. This was because the enlargement of infrastructure was both carbon and labour intensive and would also entail a commitment to pumping water for the next 50 years.
(9) Mr Mills concluded his presentation by using his slide presentation to demonstrate successful solutions. Smart water butts were capable of emptying themselves before a storm and remaining full during dry periods. Green roofs were particularly for public buildings such as bus stops and fire stations. Tree Pits such as the one in the White City, London enabled water to collect around the tree and sink into the ground, disconnected from the main drainage system. Rain gardens had clear benefits to the community whilst also serving to reduce water overrun. Projects had also taken place to make road surfaces permeable in some areas.
(10) Mr Goff asked what consideration had been given to the storage of flood water in reservoirs. Mr Mills replied that a great deal of work was being undertaken on this possibility. A consultation on this matter was due to be published as the question of water resources in the South East was one which needed to be addressed. He offered to share links to the consultation with the Committee Members following the meeting.
(11) Mr Sole asked how water companies in countries which did not have access to a coastline dealt with water. Mr Mills replied that in these cases, water would be diverted into a watercourse such as a river or stream. In very rare instances, water could be diverted into one of a series of bore holes.
(12) Miss Wright referred to a recent Monckton Parish Council meeting where representatives from Southern Water had been in attendance. The discussion had revolved around building works where concrete slush had been disposed of through the drains with the consequence that flooding had occurred. She suggested that a hotline could be installed by Southern Water so that residents could rapidly contact the company when they saw incidents of this nature taking place. Mr Mills said that Southern Water had a team made up of former Police Officers who had an educational and, to a lesser extent, an enforcement role for this problem. It was a very common problem for waste such as wet concrete to be inappropriately disposed of in this way. He said that he would consider this suggestion with his colleagues.
(13) RESOLVED that Mr Mills be thanked for his presentation and that its content be noted.