Agenda item

Southern Water future plans - Presentation


(1)          Mr David Murphy (Southern Water DWMP Programme Manager) gave a presentation on Drainage and Wastewater Management Plans (DWMPs), the slides of which can be found on the KCC webpage for this meeting.


(2)       Mr Murphy began his presentation by saying that the purpose of DWMPs was to ensure that Southern Water’s drainage and wastewater management was fit for the future and that the necessary resources were provided to cater for present and future demand, taking account of factors such as growth and climate change.


(3)       Mr Murphy said that DWMPs were new plans which had been developed by Water UK, an industry body that all water companies worked with. Water UK had formed a group consisting of experts and water company representatives to develop a framework for long term planning over the next 25 years.  A similar statutory planning framework was already in place for water resources, and the government had considered that it was necessary to develop one for drainage and wastewater.   Drainage Area Plans and Surface Water Management Plans had already been developed by individual water companies but the significance of the DWMPs was that all the plans would now be developed in the same way.


(4)       Mr Murphy continued that the benefits of the new DWMPs were that they could identify future risk in terms of flooding and pollution which would be shared with the customers.  They would also identify investment needs to build resilience.  They would support the applications for funding which were submitted to Ofwat every five years.  The most important benefit was that they would enable partnership working with other organisations, particularly those with responsibility for flood and drainage management.  He praised the work of Max Tant and of the Environment Agency in supporting the various webinars and seminars that were assisting in the development of the DWMPs. 


(5)       Mr Murphy then showed a slide demonstrating the DWMP boundaries in Southern Water’s operating area (Kent, Sussex, Hampshire and the Isle of Wight). He said that the planning framework had to consider the region as a whole, as well as at a catchment scale.  There were 11 district and river-based catchment areas in the region, four of which were in Kent.   The Plan for each of these catchments had to take account of the systems in place within them, together with their performance and the impact on customers and the environment.


(6)       Mr Murphy moved on to consideration of Risks.  DWMPs were predominantly a risk-based approach to planning.  Development of the Plans began with setting the strategic context, undertaking risk-based screening, the development of a baseline risk and vulnerability assessment, and the identification of the causes of the problem. This was followed through the identification and appraisal of options. The results of this work were then put together into the DWMP for the longer term.  The process was currently at the appraisal of options stage, where the Team had to consider their feasibility before incorporating the best ones into the investment plan following consultation with all the partner organisations. 


(7)       Mr Murphy said that the identification of fourteen risk assessments for the DWMP had taken place following full consultation at the very beginning of the process.  These risks from the wastewater and drainage systems included pollution, internal and external sewer flooding as well as environmental risks to the quality of bathing and shellfish waters. 


(8)       Mr Murphy identified the outputs from the risk assessments.  In terms of storm overflows, the region had been broken down into three categories:  Not Significant, Moderately Significant and Very Significant.  In Kent, there were very significant concerns over North Kent.  Identification of this area enabled Southern Water to focus on the reasons that this part of the county’s water systems were more problematic than in the rest of Kent.  There were 1038 storm overflows (release valves to discharge water when the capacity of the sewage system was exceeded) across the entire region.  Not all of these were active, but those which were, were identified as “high spillage.” Most of these were designed and permitted by the EA to spill in times of heavy rainfall.   Southern Water’s greatest concern was over those un-designed storm overflows were caused by the systems in place. 


(9)       Mr Murphy informed the Committee that all the risk maps could be found on Southern Water’s website.  These maps included information on the causes of the risk.  Mr Murphy recommended that all Committee Members should look at the website and, if necessary, let Southern Water know if they were able to identify any information that was either missing or inaccurate. 


(10)     Mr Murphy said that a public consultation period for the DWMP had just closed and that a further round of public consultation would take place in 2022.  The appraisal stage was dud to be completed by the end of 2021. Forward investment planning would take place in February and March 2022, including workshops with partner organisations. The final draft plan would be ready for a three-month consultation starting in June 2022.  Finalisation and publication of the DWMP would take place in March 2023.  All water companies were following the same timetable.  This would enable Ofwat to have all the information to prepare its funding plan for the period 2025 to 2030.


(11)     Mr Murphy moved on to identification of the risks in Kent.   He began with the Medway catchment area where there were 77 sewer catchments, 69 wastewater treatment works, 635 water pumping stations, over 4,000km of sewers.  Only some 17% of the land area (including the urban areas) was covered by the sewage network.  This meant that some 5% of houses were not connected to the system and had to rely on septic tanks. This was a significant risk in terms of groundwater pollution effecting water supply.  The risk was especially acute in those parts of the catchment area where development was planned.


(12)     One of the risk assessments undertaken had been in respect of rainfall exceeding sewage capacity.  The specific objective set had been for a 1 in 50-year storm.  Other objectives had been 1 in 1, 1 in 2-year and 1 in 30-year storms.  The most vulnerable parts of the Medway catchment had been identified as Tonbridge, Tunbridge Wells (south), Paddock Wood, Staplehurst, Pembury and East Peckham.   Mr Murphy said that Tonbridge had suffered despite the protection of the Leigh Barrier but that investments in improvements at Leigh should protect the town to a greater extent in the future. 


(13)        Mr Murphy said that causes of flooding in the Medway catchment had been identified.  He gave three examples. In Tunbridge Wells, only some 1% of the flow through the sewer came from homes and businesses.  Rainfall accounted for 96% of water arriving at the wastewater treatment works.  The rainfall was broken down into roads (37%), roofs (34%) and “permeable areas” (26%).  Similar figures had been identified in Tonbridge and Paddock Wood, although it needed to be noted that 85% of the flow in Tonbridge came from roads.


(14)     Mr Murphy’s second catchment area was the Stour where about 16% of the land (including the urban areas) was covered by the sewage network.   This equated to some 96% of homes in the catchment.  There were 21 sewer catchments, 392 water pumping stations and 532km of sewers.  The largest systems were in Margate and Broadstairs, Ashford, Weatherlees (Ramsgate, Sandwich and Deal) and Canterbury. 


(15)     One of the risk assessments carried out had been for internal flooding.  Mr Murphy said that this criterion of risk ranged from back-up from the wastewater system (that could be cleared away fairly easily) to heavy flooding of the entire ground floor.   It was therefore essential to identify the areas of greatest severity.  These were Margate and Broadstairs, Weatherlees and Canterbury.  The number of severe instances in these three parts of the catchment (together with Sandown on the Isle of Wight) were far higher than across the entire region.  At Weatherlees, 74% (20k per year) were caused by blockages (oils, wet wipes, greases, fats, etc). The percentage arising from blockages in Margate and Broadstairs was 96%. 


(16)     Mr Murphy continued by saying that Southern Water had carried out a series of activities to improve awareness of the problems created by blockages in the three areas.  This was educational in nature and aimed to prevent sewer misuse.  


(17)     Mr Murphy then said that other causes of internal flooding were hydraulic overload and other operational issues.  Some of the systems had not been designed to cope with the current climate.  They were very old, having been installed some 150 years earlier when the properties had been built.  These systems were vulnerable, particularly in areas where activity such as mining or quarrying was taking place.  Southern Water was investigating these sewers, often by sending CCTV cameras through them. It also had an investment programme to reline or repair sewers when they were in danger of collapsing.  Rising Mains could also burst and cause flooding and pollution. 


(18)     Mr Murphy then summed up the findings to date, including the challenges faced.  He said that a very high percentage of flow in combined sewers (97%) was rainfall.  Roads, drives, and paved areas accounted for a great deal of rainfall (80% in Tonbridge).  Roofs and permeable areas were also significant factors.  The sewage systems had been designed to prevent overflow of up to a 1 in 30-year event.  They had often been installed more than 100 years earlier and were unable to cope with the extremely high levels of rainfall presently experienced.  Some 70% of internal flooding, 80% of external sewer flooding and 65% of pollution incidents resulted from blockages caused by wet wipes, fats, oils and grease, presenting a major challenge.


(19)     Mr Murphy identified Climate Change as a major challenge.  He showed a slide for Budds Farm Wastewater Treatment Works in Hampshire which was expected to see an increase in floodwater volume of 67% by 2050 as a consequence of the predicted rise in intensity of rainfall.  If the run-off from permeable could be reduced, the result at Budds Farm would be that the increase in floodwater volume would be reduced to 35%.  This would be further reduced to 21% if all floodwater from permeable areas could be diverted to rivers and streams.  If surface water from rainfall and roofs could be removed, the increase inn flood volume would decrease to 12%.  Future flood volume could only be reduced if surface water could be reduced by 40%.  His conclusion was that at least 25% of surface removal would be needed by 2050 to offset the impacts of Climate Change, urban creep and growth.


(20)     Mr Murphy then said that wastewater systems needed to be changed.  At present, water was picked up from homes and businesses, directly from road or roof run-off.  This water went into the combined sewage system which carried both wastewater and rainfall.  Most systems contained storm tanks and storm overflows to accommodate peaks of demand.  


(21)     Mr Murphy said that building additional storm tanks was a traditional solution, but that its limitations could be demonstrated by the storm tank which had been installed on the Isle of Wight at a cost of £2.4m yet filled up within 7 minutes.  Therefore, a more sustainable solution was needed.  Could surface water be naturally separated and diverted to a water course? Could natural drainage systems be introduced that could hold the water during future intense summer storms?  This could only be done by changing and greening communities.  Trees would not only provide shade and reduce carbon emissions. They would also stop water running off permeable areas.  


(22)     Mr Murphy continued that George Park in Margate was a brilliant sustainable drainage scheme which could, perhaps be introduced more widely to help communities adapt to Climate Change.  The introduction of green roofs would enable water to run off into gutters and drains.  


(23)     Mr Murphy said that the successful introduction of sustainable drainage schemes would make a difference.  An analysis of the impact of sustainable drainage schemes had been undertaken. If they were not introduced, all water runoff would drain into the sewer network.  If home drainage systems were sustainable, the run-off would reduce to as little as 13%.  The other 87% would return to the environment as groundwater or be diverted to ponds, streams, ditches and rivers and eventually into the sea.  


(24)     Mr Murphy concluded his presentation by showing slides of a raingarden and a wetland in a country park.  He then asked the Committee to consider two questions. These were:

How do we encourage and enable communities to adapt to climate change and manage rainfall runoff differently?

How can we separate rainfall from foul water systems to reduce flooding and storm discharges, and create more capacity at the treatment works for wastewater from new homes?


(25)     Mr Lewis said that he was speaking as a Local Member for Margate.  He said that Southern Water had a very bad reputation amongst his constituents. Southern Water had been formed in 1989 as a monopoly. 


(26)     Mr Lewis then said that some privatisations had been successful but that this was certainly not the case with Southern Water which he described as “the unacceptable face of privatisation.”  It had suffered from lack of investment because the company had been more interested in selling shares than in serving the needs of its customers.


(27)     Mr Lewis continued by sating that there had been five illegal discharges in 2021 alone.  He asked why the ideas put forward during the presentation had not been put into practice during the 1990s.  He believed that Southern Water owed an apology to the people of Margate for ruining their summer and for being serial polluters (for which they had been fined).  He gave the example of a school which had planned for its pupils to pick up litter on the beach but had been prevented from doing so because of an illegal discharge.  He did not consider this to be an example of good communication on the part of the company.   He believed that if Southern Water passed on the cost of its planned investment to the customers, many people would refuse to pay due to their lack of confidence in the company.


(28)     Mr Lewis then referred to Southern Water’s campaign to educate people to avoid blockages.  He asked whether the accompanying literature was sent out in more than one language. As far as he was aware, only the English language was ever used. The same could be said for advertising on the radio and television.  


(29)     Mr Murphy replied to Mr Lewis by saying that Southern Water had pleaded guilty for its misdemeanours between 2010 and 2015.  In total, Southern Water had been fined £90m.  None of this would be passed on to the customers.   Southern Water now had a new Chief Executive who was making considerable changes to the way it operated.  The company now had new owners and a new leadership team.  It recognised that it had been at rock bottom and that it had to change and was investing heavily to ensure that it would no longer pollute the beaches.  The pollution incidents in Margate and Broomfield in 2021 were bitterly regretted and Southern Water was working in partnership with Thanet DC to clean the beaches up.  The company was heavily regulated by three different bodies. This included regulation on investment by Ofwat.  Since being fined in the summer, Southern was committed to an investment 0f £250m to ensure that illegal discharges would no longer happen.  This was accompanied by further investment in the “Storm Overflow Task Force” to reduce storm discharges by 20% by 2030.  Although radio broadcasts only used English, literature was published and disseminated in other languages. 


(30)     The Chairman said that he would invite Southern Water to attend meetings of the Committee once a year in order to discuss progress and concerns.   


(31)      Mr Hood said that Southern Water’s communication in West Kent was appalling.  He believed that there was an organisational problem of silo working. There were two teams working in Tonbridge who seemed not even to know who was working for the other one.  He considered that Southern Water’s actions should be described as “environmental criminal behaviour” rather than “misdemeanours.”  In 2020, Tonbridge and Hildenborough had experienced 267 storm overflows, contributing to some 2,521 hours of pollution.  He asked what opportunity County and District Councillors had to be fully appraised about the local wastewater infrastructure and its capacity and ability to supply new developments. He added that he had asked for this information but that it had not been forthcoming.  He then asked whether storm tanks were able to function if they were below the water table and how run off from roads was to be mitigated.


(32)     Mr Murphy replied to Mr Hood by saying that he accepted the point about inter team communications and that he would seek to have it addressed.  Southern Water was becoming far more transparent with respect to information on storm overflows.  It had recently launched a “Beach Boy” app which provided nearly real time data on local storm overflow.  DEFRA had identified local wastewater infrastructure as “critical” under the Security and Emergency Directive. This prevented Southern Water from identifying where it was, and also made it more difficult to consult local partners about DWMPs.  The Southern Water website was now publishing as much information as it could on its website.  He asked Members to contact him if they believed that there was any information that could helpfully be added to it.  He agreed that storm tanks below the water table were not the best solution and that they were, therefore, inappropriate in some locations.   A great deal of consideration was being given to the question of how to discharge runoff from roads, pavements and drives in the light of the danger of this water being polluted.  The possibility of running it through wetlands was being explored. 


(33)     Mr Sole said that the Little Stour and Nailbourne area experienced flooding every year.  This was dealt with by tankers which sucked the water away.  He suggested that there had to be a better option which was more cost effective and less noisy and cumbersome and asked when this method of working would stop.  He agreed with those who had described Southern Water’s actions in hostile terms, saying that they had let down the tourist and shellfish industries amongst others - without compensation.  He asked how the wastewater and drainage infrastructure would be able to cope with the projected major increase in housing and when raw sewage would cease to be dumped into the sea. 

(36)     Mr Murphy replied to Mr Sole by saying that Southern Water had added additional manholes so that the tankers in the Nailbourne and Little Stour area would be less disturbed when they sucked up the sewage.  Southern Water and the EA had developed a scheme to avoid tankering.  This had, however, proved to be unviable on cost grounds as it would not have been able to attract the necessary funding.  He was, therefore, unfortunately unable to give a date when this method of working would cease.  Southern Water had carried out sewer lining of the public sewer.  The problem lay with the private connections to the sewer (where Southern Water had no powers to reline), allowing groundwater to seep into the system.   He assured the Committee that Southern Water was committed to resolving this issue. 


(37)     In response to Mr Sole’s question on sewage being dumped into the sea, Mr Murphy said that the Environment Bill had gone through the parliamentary process. It included a requirement on water companies to reduce the harm from storm overflows.  This would enable the investment to be made through the usual mechanisms, but Southern Water was already moving ahead with its commitment to reduce storm overflows by 80% by 2030.  The problem was historic in that the storm overflows had been designed within the system ever since they had been built. They could not be blocked up without affecting people’s homes, businesses, hospitals and schools.  The present choice was whether to affect them or release heavily diluted water into the environment. 


(38)     Mrs Wright said that Thanet DC was continually working with Southern Water to try to resolve the local issues.  She referred to a factory in Cornwall that was near to a sewage works.  Following discussion, the two had worked together in a manner which enabled the pumping station to produce energy.  She asked whether this was an approach that Southern Water had considered. 


(39)     Mr Murphy replied to Mrs Wright’s question by saying that some 16% of current energy use was generated from Southern Water’s Wastewater Treatment Works in the form of methane gas.  It was aimed to increase this amount in future years. 


(40)     Mr Rayner said that Borough Green had experienced five related sewage bursts in 2021.  These had all resulted from the same blockage in a 90-year-old sewer.  This had resulted in the A25 being blocked up for four months.  The resultant impact was still being felt by the community.  He asked who the community should speak to in respect of this sewer, adding that local people were concerned that there could well be a repetition of this event in the future. 


(41)     Mr Rayner continued that Borough Green was expected in the Local Plan to take an additional 3,000 houses.  This was attracting a great deal of opposition because the local infrastructure would not be able to cope with this increase.  He again asked who the community should speak to within Southern Water to ask them to participate in the planning process to either give an assurance that the sewage infrastructure was going to be satisfactorily upgraded, or to explain that it would not be able to accommodate the additional buildings. 


(42)     Mrs Brown said that Southern Water very often made no comment in respect of planning applications.  She suggested that they should become more involved in commenting on the likely runoff.   She then referred to local applications for between 600 and 1,000 new homes when Southern Water’s response to the question of whether it could provide the necessary sewage infrastructure by saying that it could do so within five years.  She was also concerned about the construction of huge polyhouses. These were 80m high with sloping roofs. When it rained it sounded like a series of explosions. She asked how the runoff from these buildings compared to that from the smaller polytunnels.  


(43)     Mr Collor commented that, whilst tree planting could be useful in mitigating flooding, there could also be a drawback in urban areas if the leaves were large enough to block drains.


(44)     Mrs Parfitt-Reid said that Local Authorities should include provisions within their Local Plans specifying the actions that developers needed to undertake if planning permission were to be granted. 


(45)     Mr Rogers commented that building regulations were an invaluable tool in terms of specifying the types of materials that should be used in construction.  He then said that in his experience, Southern Water’s response time had improved greatly when flooding problems were reported. 


(46)     RESOLVED that:-


(a)         Mr David Murphy be thanked for his presentation and that its content be noted together with the comments made by Members of the Committee; and


(b)         Southern Water be invited to present an update report during the year 2022 and thereafter on an annual basis.