Banter 124: 17Jun26 Storm Overflows, with Keith Herbert

comprehensive overview of urban drainage systems, combined sewer overflows (CSOs) are automated and regulated by the Environment Agency. Need to manage rainwater separately from sewage

---

Presentation:

You are welcome to view this presentation by clicking on the pages above. A markdown copy (ie text only) is at the bottom of this page

---

Meeting Summary:

Jun 17, 2026 11:49 AM London ID: 834 5460 8536

Quick recap

This meeting was a webinar focused on storm overflow and sewage issues, featuring Keith Herbert from Southern Water presenting on combined sewer overflow (CSO) management and solutions. Keith explained that Southern Water's £1.5 billion program aims to reduce CSOs by taking stormwater out of the system rather than building more tanks, as tanks can quickly fill up and create significant CO2 emissions. He detailed the technical approach including hydraulic modeling, disconnecting improper roof connections, installing soakaways, and working with developers to implement sustainable drainage systems. The discussion covered practical solutions like using dye tests for homeowners to determine where their roof runoff goes, pricing for different types of stormwater disconnection work, and the need for public engagement and legislative changes to effectively address the issue. Participants asked questions about local impacts, communication strategies, and the relationship between stormwater management and planning policies, with Keith emphasizing that successful solutions require partnership between water companies, local authorities, and homeowners rather than just water company efforts alone.

Next steps

Ally

• Investigate and promote the use of allotments in Bembridge village to support food security, considering local land constraints (e.g., RSPB reserve).

• Use dye tracing (sewer tracing dye) to determine where roof and property runoff goes in Bembridge, and encourage other local householders to do the same.

Sue

• Distribute information and reminders to parish residents about the "three P's", sustainable driveway/extension practices, and the benefits of permeable surfaces, using materials from Southern Water or similar sources.

• Encourage and support the distribution of water-saving devices (e.g., slow shower heads, water butts) and information on stormwater management to residents via parish channels.

Collaboration

• Andrew Maliphant (and/or Great Collaboration team): Gather and share good practice information, data, and communications materials on stormwater management and correct property drainage for use by local communities and parish councils.

• All attendees (especially parish and local councillors): Advocate for and support the inclusion of sustainable drainage requirements in local planning processes, referencing relevant Building Regulations (H3) and encouraging enforcement by local authorities.

• All attendees: Report incorrect or problematic drainage connections to Southern Water or the Environment Agency when identified.

• Southern Water (as referenced by Keith): Continue public engagement and communications campaigns in areas where connectivity work is being undertaken, including public drop-ins and information on available rebates for correct stormwater management.

• All attendees: Monitor and respond to updates in the National Planning Policy Framework (NPPF) regarding requirements for sustainable drainage in new developments and share relevant information locally.

• All attendees: Support and participate in local film screenings and action groups (e.g., People's Emergency Briefing) to raise awareness and coordinate community responses to water, flooding, and food security issues.

Summary

Storm Overflow Issues Discussion

Andrew Maliphant hosted a webinar session in place of Graham, who was unavailable due to sailing. Ally discussed ongoing issues with storm overflows in Bembridge on the Isle of Wight and mentioned their recent campaign in the press regarding these problems. The discussion briefly covered Southern Water's service area, which covers parts of the southeast including East and West Sussex, Kent, Hampshire, and the Isle of Wight.

Climate Adaptation Communication Strategies

Andrew Maliphant discussed the need for better language and communication around climate adaptation topics, noting that many organizations are working in this space including a charity helping with civil aid in emergencies and the Mac Hub initiative. He expressed concerns about the rapidly changing world and questioned what advice should be given about essential life needs like local water, food, and shelter. The discussion included casual conversation about travel experiences in Spain, with Keith and Frank sharing their recent trips to the region.

Climate Resilience Terminology Discussion

The meeting focused on discussing climate and resilience terminology, with Andrew Maliphant noting that "resilience" is currently a more effective term than "climate" or "net zero" when engaging the public. The group discussed the importance of identifying regional locations to better understand local challenges, and Keith from Southern Water was introduced as a key speaker to discuss storm and flood issues, particularly regarding combined sewer overflows and urban drainage strategies. The meeting was structured to provide balanced information for local councilors and concerned residents, with Keith preparing to share his expertise on water company approaches to these challenges.

Urban Drainage Systems Overview

Keith provided a comprehensive overview of urban drainage systems, explaining that combined sewer overflows (CSOs) are automated and regulated by the Environment Agency to protect homes from flooding. He clarified that wastewater infrastructure is designed for dry weather flow times three, but during rain it handles dry weather flow times ten, highlighting the need to manage rainwater separately from sewage. Keith described his team's work in reducing storm overflows through a £1.5 billion program targeting over 200 CSOs, using AI models to predict sewer levels and identify sources of excess water through heat mapping techniques.

Rainwater Management System Solutions

Keith explained the process of managing rainwater in the sewer system, highlighting the challenges of using large storage tanks due to their rapid filling and high CO2 footprint. He discussed disconnecting roofs from the sewer system and implementing solutions like soakaways and permeable paving to handle stormwater more sustainably. Keith also described their approach of identifying and disconnecting large buildings connected to the foul sewer, such as an ambulance depot, to reduce overflow issues.

Storm Overflow Reduction Strategies

Keith discussed efforts to reduce storm overflow spills by disconnecting properties from combined sewers and installing sustainable drainage systems. He presented a case study from Fareham where disconnecting over 50 properties and installing soakaways reduced spills from 92 to 12 times in 2025. Keith emphasized that while water companies must reduce storm overflows by law, success requires collaboration with landowners, local authorities, and the public, as the issue extends beyond just water company responsibility.

Water Management Challenges and Solutions

Keith discussed water management challenges and solutions, explaining that water companies pay for soakaways as they reduce the need for treated water in the system. He addressed questions about storm overflow management, explaining that while some stormwater does go into sewers too frequently, efforts are being made to separate stormwater from foul water in new developments. Keith also discussed options for addressing groundwater ingress into sewer pipes, including sealing networks or treating flow, and shared that wetlands could potentially be used as a treatment option with regulatory support. The discussion concluded with Keith explaining community engagement approaches for connectivity work, noting they achieve 50-60% response rates from property owners during public consultations.

Storm Water Drainage Approaches

Keith from Southern Water explained approaches for identifying and addressing storm water drainage issues, including using dye tests and working with drainage contractors. He discussed the company's efforts to prevent paving over land that naturally absorbs water, and mentioned water companies offer rebates for diverting storm water away from their systems. The discussion included questions about community communication efforts, with Sue suggesting local parish councils could distribute information about water conservation practices, and Andrew noting the need for better coordination between national planning policies and local water management.

---

Chat:

00:14:40 David Newman (Blackbird Leys): I have to leave at 1240 for another meeting. 00:46:48 Ally De Trey: How do I raise my hand? 00:52:09 David Newman (Blackbird Leys): Have to leave for another meeting. 01:05:41 Katherine Stott: Thank you Keith - this was really interesting - I'm afraid I have to leave for another meeting - apologies! 01:06:38 Peter Bates (SSECAM) Cambridgeshire: Thanks I need to go to another event

01:09:36 Lynn Parker, Shropshire: For info Smart water butts ease flood risk with advanced wireless technology - Shropshire Council Newsroom

01:09:53 Helen Pratt - Bucklebury, West Berkshire: Thank you Keith - very interesting 01:10:04 frank deas Killearn: many thanks Keith 01:14:03 Ally De Trey: Yes, I was 01:17:25 Ally De Trey: Got to go now

---

Audio-Transcript:

142 00:14:21.820 --> 00:14:32.999 Keith Herbert: Sure, thanks for the introduction, and thanks for having me. My name's Keith Lough. I've worked in the water industry about 20 years.

143 00:14:33.130 --> 00:14:40.640 Keith Herbert: Mainly in operations, but as… as you all know, the… the situation regarding

144 00:14:40.820 --> 00:14:48.000 Keith Herbert: Untreated sewage being released, detonated, in about 2021, which I can't go into that.

145 00:14:48.180 --> 00:15:03.680 Keith Herbert: And, what… what that happened is most water companies, whether you live in North, South, Midlands, or wherever, have strategies now for dealing with combined sewer overflows and better urban drainage. So, that's been my main occupation now for…

146 00:15:03.680 --> 00:15:15.029 Keith Herbert: getting on for 5 years. So, when I do these things, it's difficult to know what level to pitch it at, because it is a very technical subject. And on one hand, I could be…

147 00:15:15.200 --> 00:15:19.370 Keith Herbert: delivering a presentation to industry experts, and I could,

148 00:15:19.370 --> 00:15:38.820 Keith Herbert: I can embellish and go into very great detail, and some days I'm dealing with very, very angry people who have just read their social media feed and their minds made up, and I can't go into so much detail. So, what I've done today is I've pitched it at the level of educated adults with a view of, you know, a lot of parish councillors or town councillors who are…

149 00:15:38.820 --> 00:15:57.840 Keith Herbert: dealing with concerned residents and kind of want the balanced view of it. So that's going to be the main meat on the bone today, and just to kind of go over it, no matter where you live, all water companies will be tackling it in some way, shape, or form. So, what we'll go through today is my learnings and of,

150 00:15:58.300 --> 00:16:03.630 Keith Herbert: of about 5 years of going through it, so if I can just share my screen…

151 00:16:04.410 --> 00:16:06.380 Keith Herbert: Can everybody see my screen?

152 00:16:07.030 --> 00:16:07.560 Cathy Wynne - Kent: Yeah.

153 00:16:07.800 --> 00:16:11.010 Keith Herbert: Perfect. How about now? Is the full screen there?

154 00:16:11.010 --> 00:16:12.020 Andrew Maliphant Great Collaboration Gloucestershire: Yay!

155 00:16:12.020 --> 00:16:13.890 Keith Herbert: Lovely, okay, right.

156 00:16:13.940 --> 00:16:33.539 Keith Herbert: I will start with just a few caveats and kind of myth-busters before I go on, because I kind of need to give everyone a basic grounding in urban drainage before I go into the nuts and bolts of it. So, the stories you hear about someone pressing a red button and releasing sewage indiscriminately, because it's cheaper.

157 00:16:33.540 --> 00:16:40.250 Keith Herbert: is… is a fabrication. Combined sewer overflows are… automated, regulated.

158 00:16:41.130 --> 00:16:48.259 Keith Herbert: by a certain flow rate, by the Environment Agency, and, like them or not, they're there to protect something.

159 00:16:48.660 --> 00:16:54.510 Keith Herbert: mostly people's homes. So, where I live on the Isle of Wight, and areas of South Hampshire.

160 00:16:54.900 --> 00:17:11.329 Keith Herbert: If we just block these things up, people would flood so frequently that their homes would be uninhabitable. So combined sewer over… overflows protect probably hundreds of thousands of homes from flooding, so the option just to block them up doesn't exist.

161 00:17:12.319 --> 00:17:26.680 Keith Herbert: the next point is what we use our sewers for. If water companies only had to treat sewage, we wouldn't need them. The fact of the matter is, we treat rainwater as well. So with…

162 00:17:26.980 --> 00:17:35.129 Keith Herbert: Generally, as a rule of thumb, wastewater infrastructure is designed for dry weather flow, so kind of summer flow, after two weeks' worth of no rain.

163 00:17:35.130 --> 00:17:50.059 Keith Herbert: times 3. That's what the general basis for the design of our sewage apparatus is. Dry weather flow times 3. When it rains, we get dry weather flow times 10, so 10 times the normal flow comes through our system. So, we only had to treat sewage, we wouldn't have CSOs.

164 00:17:50.760 --> 00:18:03.230 Keith Herbert: And then, networks have a finite capacity. You know, we cannot push the limits of it. We are the flood people, or it becomes prejudicial to the treatment, because sewage works do not like

165 00:18:03.340 --> 00:18:18.890 Keith Herbert: rainwater coming in there. We mainly rely on biological treatment, so the bugs do the treatment at the works. If we water that down with rainwater, we get a poorer quality effluent, and we end up polluting that way either. So, there is an upper limit as to what we can actually achieve with our network.

166 00:18:19.380 --> 00:18:33.940 Keith Herbert: And my job, really, is I don't really work on our apparatus, I work on taking rainwater out. So, roads, roofs, driveways, a third-party apparatus, that's where I spend the bulk of my time, working with landowners to remove that.

167 00:18:33.940 --> 00:18:40.440 Keith Herbert: From the foul sewer, because that's what's causing the excess flow and the combined sewer overflows.

168 00:18:40.740 --> 00:18:45.199 Keith Herbert: Then, just a couple of other points, is that…

169 00:18:45.310 --> 00:18:51.390 Keith Herbert: The actual impact of CSOs, the environmental impact of them, as disgusting as it is.

170 00:18:51.710 --> 00:19:00.839 Keith Herbert: is poorly understood. So, if you look at the health of our rivers and our waterways, if you were to take CSOs out of the equation overnight.

171 00:19:01.710 --> 00:19:10.860 Keith Herbert: we would still have pollution. Things like agriculture is a big source of eutrophication, nitrates and phosphates in our waterways.

172 00:19:10.880 --> 00:19:30.859 Keith Herbert: And road runoff as well. So all the roads we drive along, generally those roads either go into our sewers or they go out to the environment. That road runoff has hydrocarbons, microplastics, brake disc stuff, all that stuff just gets washed in. So, yes, CSOs, quite rightly, attract a lot of scrutiny and attention, but they're not the only source of pollution.

173 00:19:31.520 --> 00:19:50.379 Keith Herbert: And then finally, my personal experience of this is, in one way, it's a good thing that water companies have got so much scrutiny. So they… in 15 years in the industry, we were the silent service, no one really knew about us, and we just went on in the background. In the 5 years, it's all just detonated.

174 00:19:50.380 --> 00:19:55.659 Keith Herbert: And it's actually been a good thing, because we get a lot of focus and energy. However.

175 00:19:55.730 --> 00:20:04.399 Keith Herbert: painting water companies as the pantomime villain is affecting retention. So if we have a job vacancy, it's difficult to recruit.

176 00:20:04.750 --> 00:20:11.059 Keith Herbert: People who are of certain dispositions can't work for us because they just can't handle the scrutiny.

177 00:20:11.360 --> 00:20:26.469 Keith Herbert: And, we need good, intelligent, dedicated people to come in and fix this, and that's hard to come by if people think we're all crooks when we're not. So that's kind of one of the, you know, the unintended effects of these high levels of scrutiny.

178 00:20:26.940 --> 00:20:44.710 Keith Herbert: Ben, just a little bit about my team, and I'd emphasize the point that if you're just not in the Southern Water region, all the companies have some teams tackling what I'm tackling. We formed in 2021, and we were a research and development project, funded by our owners for a good 3 years.

179 00:20:44.710 --> 00:20:47.130 Keith Herbert: With the view of finding new ways

180 00:20:47.130 --> 00:21:08.879 Keith Herbert: techniques to reduce storm overflows, because generally, we'd build a big tank at the end of the pipe, or we'd put more through the works, but what we've been trying to do is demonstrate that actually taking the flow out from the system is more effective than dealing with it once it's in there. And that's grown to where we are now, where we're administrating a 1.5 billion pound program to fix

181 00:21:08.880 --> 00:21:11.150 Keith Herbert: well over 200 CSOs.

182 00:21:11.840 --> 00:21:27.610 Keith Herbert: So, I'm gonna go into the technical stuff now, because this is where I find my energy. What you can see on the screen is a level in the sewer. So, the solid brown line is the level in the sewer, and the blue line is the rainfall.

183 00:21:28.120 --> 00:21:35.669 Keith Herbert: Either side of the brown line, you can see there's light brown tram lines, so dashed lines. That's an AI model predicting

184 00:21:35.770 --> 00:21:54.770 Keith Herbert: how the level in the sewer will respond to rainfall. So you can see when it rains, the brown line goes up, and the lines either side of it loosely follow it. So on there, on the far right-hand side, when it goes above the red line, that's where the combined sewer overflow activates, the system reaches its capacity, and we spill.

185 00:21:55.940 --> 00:22:06.479 Keith Herbert: And the I.O. model is kind of tracking that and predicting where that level will go. So, it stands to reason, if you can plot it on a graph, you can get the data behind it.

186 00:22:06.790 --> 00:22:13.100 Keith Herbert: And here's what we have. So on the… here's a list of our combined sewer overflows on the Isle of Wight.

187 00:22:13.910 --> 00:22:26.569 Keith Herbert: And what this gives you is a percentage chance that that storm overflow will operate, given a set rainfall event. So if we look at the top, the key Newport, if we get 5 millimeters of rain in an hour.

188 00:22:26.570 --> 00:22:33.999 Keith Herbert: That's got a 20% chance of spilling. If we get 10 millimeters of rain an hour, it's got a 67% chance of spilling, so on and so forth.

189 00:22:34.140 --> 00:22:47.879 Keith Herbert: Whereas if you go to the bottom, it's… it's pretty depressing reading. Fairley Road Newport has a 100% chance of spilling to 5 millimeters of rain, so that's… that's pretty depressing and not in line with anyone's expectations. However.

190 00:22:48.200 --> 00:23:04.200 Keith Herbert: one would think that you don't have to take a lot of stormwater out to drastically improve the performance of that particular combined sewer overflow. So, before we start digging up the road or building stuff, we really need to do what characterize the combined sewer overflow. How sensitive is it to rainfall?

191 00:23:04.280 --> 00:23:09.140 Keith Herbert: And how much rainfall do we think we need to take out of the system to achieve a better performance of that?

192 00:23:10.310 --> 00:23:14.130 Keith Herbert: Then we look at the hydraulic model to tell us

193 00:23:14.300 --> 00:23:18.819 Keith Herbert: where the water's coming from. So, we have these heat maps produced.

194 00:23:19.280 --> 00:23:24.659 Keith Herbert: And what these heat maps tell us is, in a particular catchment, where the water's coming from.

195 00:23:24.780 --> 00:23:30.160 Keith Herbert: And where we need to look for it. So, on the left, we've got cows, on the right we've got wooden.

196 00:23:30.240 --> 00:23:39.770 Keith Herbert: And the darker the area, the more water is coming from that particular area. So in that area, you'd expect to find car parks, roads, roofs.

197 00:23:39.770 --> 00:23:54.859 Keith Herbert: with all of their drainage connected into the foul sewer, and that would be a very happy hunting ground to target combined sewer overflow reduction, because if those things are connected when it rains, it overwhelms our system. We need to work with whoever owns that land to take that stormwater out.

198 00:23:56.080 --> 00:24:01.080 Keith Herbert: And then, there are no shortcuts for the next step. We need to die test to prove that.

199 00:24:01.320 --> 00:24:12.139 Keith Herbert: So, on the left-hand side, we have a map of an area in Gosport where all the greens is not connected, and all the reds are connected. So, there's no shortcut, we need to

200 00:24:12.140 --> 00:24:29.679 Keith Herbert: Tip dye down highway gullies, down people's downpipes, and build up a picture of what's actually connected, so we can work with the owner of the road or the properties to disconnect that and take that water out, because that rainwater doesn't need treating. Its only purpose is overwhelming and serves to overwhelm our system.

201 00:24:29.680 --> 00:24:31.950 Belinda Baker: Hey, this… lost. Good, come on.

202 00:24:31.950 --> 00:24:32.530 Keith Herbert: I'm gonna…

203 00:24:32.530 --> 00:24:33.090 Belinda Baker: running around.

204 00:24:33.090 --> 00:24:35.600 Keith Herbert: Was that a question, or is someone just not on mute?

205 00:24:36.160 --> 00:24:37.110 Belinda Baker: Wow.

206 00:24:37.970 --> 00:24:39.720 Belinda Baker: What do we fit with you?

207 00:24:39.720 --> 00:24:42.800 Andrew Maliphant Great Collaboration Gloucestershire: Can we get questions to the end, please? Because Keith's in the flow here.

208 00:24:42.800 --> 00:24:43.560 Belinda Baker: Mmm.

209 00:24:43.810 --> 00:24:44.320 Keith Herbert: Sure, okay.

210 00:24:44.320 --> 00:24:45.629 Belinda Baker: I mean, Chris was back in.

211 00:24:47.410 --> 00:25:06.380 Keith Herbert: And then, kind of moving into the process, first thing we do is we look at our network to make sure that every last drop is being treated, and our network is operating at full capacity. So on the bottom left, you can see the kind of green tanks on the left.

212 00:25:06.380 --> 00:25:12.240 Keith Herbert: They were kind of left there, as a redundant apparatus, and we're now using them as storage.

213 00:25:12.240 --> 00:25:21.409 Keith Herbert: On the right-hand side, the kind of, cartoon diagram, you can see a 90 liter a second pumping station pumped to a 60 liter a second pumping station.

214 00:25:21.410 --> 00:25:33.169 Keith Herbert: Again, you know, that's just not going to work very well, because the downstream pumping station's going to get overwhelmed, so we'd look to hold back flow in that situation. And then at the top, we're kind of using smart AI to build

215 00:25:33.170 --> 00:25:46.699 Keith Herbert: balance our network, so there's a kind of gate valve you can see at the top there. That gate valve holds back flow to protect combined sewer overflows downstream, so we, you know, we hold back flow within the pipes, so we only spill at the last minute.

216 00:25:47.420 --> 00:25:56.150 Keith Herbert: However, the tanks that you can see on the left, they hold about 10 million liters worth of water.

217 00:25:56.320 --> 00:26:05.859 Keith Herbert: And you'd look at that and you'd think, wow, they're never gonna fill up. They're absolutely huge. This is what the trend looks like over the course of a winter.

218 00:26:06.100 --> 00:26:09.239 Keith Herbert: And you can see they fill up in about 12 hours.

219 00:26:09.400 --> 00:26:17.699 Keith Herbert: And that flow needs to be returned back to treatment. And you can see on the left-hand side, we're trying to return the flow, and it rains again. Trying to return the flow, and it rains again.

220 00:26:17.820 --> 00:26:35.419 Keith Herbert: On the right-hand side, you can see that those big tanks have caught the occasional spill, but they fill up really quickly, and they take about 4 days to return. So, if you're going to take anything away from this particular chart, water companies aren't just going to go around and build tanks everywhere, and they're going to be successful.

221 00:26:35.690 --> 00:26:44.590 Keith Herbert: And if you're, you know, I've heard some people talking on the call already about climate change. A cubic meter of water weighs a ton.

222 00:26:45.020 --> 00:26:51.259 Keith Herbert: And one of the biggest costs for water companies is power, of just moving this water around in circles.

223 00:26:51.650 --> 00:27:03.229 Keith Herbert: And there comes a point of handling all this rainwater. The environmental benefit caused by not spilling isn't offset by the CO2 footprint of just pumping all this water around.

224 00:27:03.310 --> 00:27:17.549 Keith Herbert: So, tanks aren't generally going to work, especially in big urban areas, because they fill up and they stay full, and then they've got the unintended consequence of huge CO2 footprint of handling what it is. So the only real sustainable way to do it is to take the water out.

225 00:27:19.300 --> 00:27:26.940 Keith Herbert: Here is kind of the next step in our spill reduction process, is where developers have built a new estate.

226 00:27:26.950 --> 00:27:34.750 Keith Herbert: And they've separated out their stormwater. They've done the right thing. So they've got a foul system for toilets, sink, dishwashers, and they've got a storm system for roads and roofs.

227 00:27:34.750 --> 00:27:57.080 Keith Herbert: But they've had nowhere to put it, so they've put it into our sewer. So on the right-hand side, you can see exactly that. You can see the blue line, which is the storm sewer, and the brown line, which is the foul sewer, and then they join up, which is a photograph that I took when it was raining. So, again, that's just all storm water. It doesn't need to go in our system, we just need to put it somewhere else, i.e. the environment, or in a soakaway, or in a storm drain.

228 00:27:57.080 --> 00:27:59.940 Keith Herbert: Because, again, that's just water that doesn't need treating.

229 00:28:01.650 --> 00:28:06.800 Keith Herbert: Then, as you saw from the kind of diagram earlier, we know which roofs are connected.

230 00:28:06.850 --> 00:28:24.599 Keith Herbert: And we go through almost like a hierarchical process with these roofs. First of all, can we just disconnect them? So, take the water out of one pipe and put it somewhere else. That's the best thing we can do. Or we work with customers to dig soakerways in their back garden, because each one of these houses can put about 60 tons of water

231 00:28:24.600 --> 00:28:27.649 Keith Herbert: Into our system every year, just through rainfall.

232 00:28:27.650 --> 00:28:46.220 Keith Herbert: And some, you know, there's pretty cool stuff that you can do with rainwater on properties. And we've also been paying people to de-pave. So the bottom two pictures is a before and after picture, where someone's got all these concrete blocks, and we're paying people per square meter to depave, and these people have put permeable paving and shingle down, which

233 00:28:46.220 --> 00:28:51.559 Keith Herbert: You know, in my view, not only looks a lot nicer, but just doesn't run off and cause flooding and pollution problems elsewhere.

234 00:28:52.370 --> 00:29:00.520 Keith Herbert: And then we have big maps done of the catchments, and we have all the buildings more than 300 meters squared coloured in red.

235 00:29:00.930 --> 00:29:11.279 Keith Herbert: And we go and knock on the door of all of those buildings and say, you know, is your roof water connected? So in the middle picture, there's a big ambulance depot, the big green building.

236 00:29:11.590 --> 00:29:27.030 Keith Herbert: And, it was about 3,000 meters squared in total, all connected into the foul sewer. And we disconnected that. So, a huge amount of flow coming off that one roof, and causing the CSO to activate downstream.

237 00:29:28.110 --> 00:29:43.539 Keith Herbert: And then the final part is we work with local authorities to install sustainable drainage on the public highway, so that the single biggest contributor towards storm overflows is runoff from the public highway. And across the region, we want to work with local authorities to

238 00:29:43.540 --> 00:29:48.760 Keith Herbert: put in sustainable drainage, and what I mean by that is little rain gardens by the side of the road that soak

239 00:29:48.760 --> 00:29:53.630 Keith Herbert: Water away, tree pits, permeable paving.

240 00:29:53.630 --> 00:29:57.850 Keith Herbert: That just takes pressure from our system, and then, you know, in my view, leaves…

241 00:29:57.850 --> 00:30:22.480 Keith Herbert: leaves the area a lot nicer, because people want to spend time where there's a bit of greenery in town centres, and, you know, it's got some biodiversity benefits, it helps pollinating insects, and urban cooling, and all those fringe benefits, but from my selfish perspective, it, it stops rainwater getting into the foul sewer. And then in the, the kind of swales and ditches that you can see, that's in a primary school.

242 00:30:22.480 --> 00:30:31.830 Keith Herbert: Where all of the roof drainage from the primary school now is diverted into that ditch with kind of stepping stones and a wildfire meadow in the field for the kids to play in.

243 00:30:32.940 --> 00:30:37.710 Keith Herbert: So, I'm just going to give a case study to kind of bring all that together.

244 00:30:37.800 --> 00:30:55.509 Keith Herbert: In Ferrum, there's a CSO in the high street, and it releases untreated sewage into the River Wallington, which is a shellfish water, a ramsar, which is a wetland designation, it's a special area of protection, a SSSI, and it affects a bathing water, and in

245 00:30:55.510 --> 00:31:01.159 Keith Herbert: In 2023, it's built 92 times, which is… which is completely unacceptable.

246 00:31:01.750 --> 00:31:09.030 Keith Herbert: So, going through the process, we looked at the heat map, and we found out, you know, where the hydraulic model thought the stormwater was coming from.

247 00:31:09.420 --> 00:31:14.080 Keith Herbert: And we die-tested everything, and we found out on the diagram on the right that

248 00:31:14.300 --> 00:31:23.420 Keith Herbert: Almost every single roof property that we tested was connected to the foul sewer, and even some of the public highway, which is coloured in brown, was connected as well.

249 00:31:23.420 --> 00:31:37.720 Keith Herbert: So, we went door-to-door, and we disconnected people, and the photograph on the left is where we've put a soak away in for a customer, in that circle there. Underneath there, there's some crates in the soak away. And on the right, we found a whole car park connected.

250 00:31:37.720 --> 00:31:48.109 Keith Herbert: So we put that into a soakaway and stormwater system there, and that car park gave us 3,500 meters squared of impermeable area that is now no longer connected.

251 00:31:50.050 --> 00:32:00.109 Keith Herbert: And then we disconnected the large warehouse, which was over 2,000 meters, and in the end, all in all, we got over 50 properties disconnected from the system.

252 00:32:00.590 --> 00:32:06.369 Keith Herbert: Now, if you can remember this chart from earlier, the brown line is the level in the sewer.

253 00:32:06.560 --> 00:32:20.049 Keith Herbert: and the dotted line is where the AI model has predicted a spill. And here's two examples of where the AI model has predicted a spill, but we haven't actually had a spill because of all the stormwater that we've removed.

254 00:32:20.050 --> 00:32:34.319 Keith Herbert: So, in essence, my job is to kind of confuse this AI model into thinking that, well, you should have had a spill, but you didn't, because it doesn't understand why, and, well, the reason why is because it has got a drain a car park, all those 50 roofs, and all of those buildings as well.

255 00:32:35.410 --> 00:32:54.049 Keith Herbert: So, about a year on, we've removed a hectare of rainwater and permeable area from the system, and in 2025, although it was a dry year, it only spilt 12 times, which is probably 12 too many, but still, way down from the 90 odd it had before.

256 00:32:54.090 --> 00:33:11.350 Keith Herbert: And it has survived a 15mm rainfall event, which is quite significant. So, the blue line is the predicted spill count, and the red line is the actual spill count for 2025. So, it's still tracking way below where the AI model would say it is.

257 00:33:11.870 --> 00:33:20.439 Keith Herbert: So, what's next? We continue into large urban areas to try and find out where the water's coming from.

258 00:33:20.580 --> 00:33:29.359 Keith Herbert: and also almost build up a picture of how much this stuff is going to cost. So I could tell you that if you're going to go door-to-door disconnecting domestic properties, you'd pay between

259 00:33:29.360 --> 00:33:45.159 Keith Herbert: 150 and 250 pounds per square meter. Soakways are a bit cheaper, but the real value comes in finding big warehouses, schools, churches, community centres connected, because the non-domestic houses, you pay £50 per square meter, because you get more… more bang for your buck.

260 00:33:45.160 --> 00:33:52.130 Keith Herbert: And then if you want to work with local authorities for highway suds, it's more expensive, £300 to 500 pounds per square meter.

261 00:33:52.820 --> 00:33:53.880 Keith Herbert: So.

262 00:33:54.270 --> 00:34:09.169 Keith Herbert: there's kind of my successes over the course of a few years. Saved well over 500 spills across all of those CSOs. But, a question that I get asked quite a lot is, how can I help?

263 00:34:09.370 --> 00:34:14.929 Keith Herbert: So, you know, I always ask everyone to look at their property and say, you know, do you need

264 00:34:15.020 --> 00:34:31.770 Keith Herbert: all the permeable stuff. It's quite… everyone's generally got a driveway nowadays. People extend and build a conservatory. There's ways of doing it with water butts and soakerways where you don't need to drain it into the foul sewer, and make sure that your property is connected properly.

265 00:34:31.820 --> 00:34:41.769 Keith Herbert: Always try and collect rainwater with water, but slow it down. Can you divert your downpipes onto your flower bed so it doesn't need to go into the sewer?

266 00:34:41.889 --> 00:34:43.420 Keith Herbert: And then,

267 00:34:44.320 --> 00:34:55.120 Keith Herbert: speak up for green places in your community, take an interest in local planning matters. Again, I'll go through in a bit more detail, but water companies aren't statutory consultees in the planning process.

268 00:34:55.199 --> 00:35:04.860 Keith Herbert: And there's an automatic right to connect. So generally, all these new houses that are being built, water companies don't get much of a say in where that's ultimately connected.

269 00:35:04.860 --> 00:35:21.639 Keith Herbert: It should be common, but you only flush the three P's, pee, poo, and paper. We still see loads of problems with wet wipes, and most blockages and problems are caused by wet wipes in the sewer. And then, if you do see something that's not right, report it to either the Environment Agency or your local water company.

270 00:35:22.800 --> 00:35:27.890 Keith Herbert: Now, going into a bit more detail about the link between CSOs and water quality.

271 00:35:28.050 --> 00:35:40.620 Keith Herbert: All the bathing water beaches that you see, the Environment Agency goes out once a week and tests the bathing water for intestinal entococci and E. coli.

272 00:35:40.740 --> 00:35:46.709 Keith Herbert: Now, a campaigner would say, well, once a week isn't good enough. It's just one point in time.

273 00:35:46.780 --> 00:36:03.250 Keith Herbert: And, you know, you can't answer the question, is it safe to go in? Is it safe for me to swim? Now, the problem with bacteriological sampling is it needs to go off to a laboratory and be analyzed for, you know, 24 to 48 hours until you get the results back.

274 00:36:03.410 --> 00:36:22.700 Keith Herbert: Now, we came across a kit that took hours rather than days to get a result, because it measures a proxy, and we gave it to some citizen scientists to say, go and have some fun with this. And what they decided to do is take a sample every day from Sandown and Yavelin Beach on the Isle of Wight.

275 00:36:22.760 --> 00:36:32.560 Keith Herbert: And here are the results. So, if there's a… the bar chart is the E. coli result, and if there's a dot underneath it, there was a combined sewer overflow on that day.

276 00:36:32.640 --> 00:36:50.159 Keith Herbert: I think it would be fair to say that there's muddled results. There are high results on days where there haven't been spills, and there are low results on days where there has. So really, the next step for us is to kind of show this to a statistician and try and draw conclusions from it. But,

277 00:36:50.370 --> 00:36:51.450 Keith Herbert: again, it…

278 00:36:51.490 --> 00:37:05.949 Keith Herbert: trying to draw a link between water quality and CSO activation is quite hard, because generally when it rains, you get a lot of runoff from agriculture and the roads, and could you blame that particular high result on the CSO or the CSO itself? I don't know, it's very, very difficult to do.

279 00:37:05.960 --> 00:37:18.699 Keith Herbert: And I think you'd be a very rich person if you could draw that link, but not defending CSOs, I'm trying to build up a balanced picture of their actual impact here. My personal view is that there are some CSOs that profoundly affect the water course.

280 00:37:18.700 --> 00:37:27.970 Keith Herbert: But I think there are some that don't, and we need to kind of take a balanced view on which aspects of urban drainage we deal with to improve water quality and which ones we don't.

281 00:37:28.030 --> 00:37:44.579 Keith Herbert: Those of you who are familiar with the regulation know that the Environment Act got done up, and it's putting a requirement of water companies to measure real-time, upstream, downstream of CSOs, and then what that'll do over the next 5 years is to answer that question and build up a better picture of

282 00:37:44.680 --> 00:37:48.069 Keith Herbert: water quality and how much impact CSOs have.

283 00:37:49.440 --> 00:38:07.050 Keith Herbert: The other activities that my team and I do is really to do with lobbying, planning, and improvement. So, some water companies are already doing area-based charging. I think United Utilities do, Anglian do, and what it means by that is we charge companies

284 00:38:07.140 --> 00:38:12.269 Keith Herbert: by their area. So, at the moment, the most are…

285 00:38:12.270 --> 00:38:26.639 Keith Herbert: non-domestic customers can pay is about £2,000 for their surface water drainage, whereas if you've got, say, an Amazon-style distribution center, that's bonkers. So much flow is going to come off there. And what we hope it will do is encourage

286 00:38:26.640 --> 00:38:32.280 Keith Herbert: People with large and permeable areas to think more about their drainage and how they could drain it more sensitively.

287 00:38:32.310 --> 00:38:50.449 Keith Herbert: And then we're reviewing our stormwater management policy. So, to be clear, we cannot reject new applications to, connect water to our system. We can't object to planning applications or reject it. Unfortunately, that went to the Supreme Court.

288 00:38:50.450 --> 00:39:07.800 Keith Herbert: about 17 years ago, Welsh Water versus Barrett Developments. Welsh Water argued that you can't connect into their system, it will cause flooding and pollution. Barrett Holmes said that you don't have a choice. It went to the Supreme Court, and it ruled in Barrett's favor. And from that point onwards, there was an automatic right to connect, an absolute right to connect.

289 00:39:07.800 --> 00:39:25.400 Keith Herbert: Now, we don't necessarily think that that's the right thing for CSOs, because if more stuff is connected, my team are going to have to take it out, which is quite frustrating. So, it's about working with local authorities and planning authorities to encourage developers to do the right thing. Speaking positively.

290 00:39:25.680 --> 00:39:40.879 Keith Herbert: big developments are generally really good, and you see lots of sustainable drainage. I would say that it's the cumulative impact of lots of smaller things that's the problem, so driveways, infills, conservatories, that's probably a bigger problem that needs tackling, rather than bigger developments.

291 00:39:41.930 --> 00:39:57.429 Keith Herbert: And then, Schedule 3. So, this is a piece of legislation that would really help us. It's already been implemented in Wales. It's Schedule 3 of the Flood and Water Management Act. Now, that removes the automatic right to connect, which doesn't exist in Scotland or Wales.

292 00:39:57.570 --> 00:40:09.859 Keith Herbert: And it allows water companies to stop development on the grounds of capacity. And it also makes sustainable drainage mandatory for all developments. Now, we really want that piece of legislation enacted. We think it's really going to help.

293 00:40:09.860 --> 00:40:19.640 Keith Herbert: So, as things stand, the government isn't providing any timescales on that, which is… which is quite frustrating. And then, we are a statutory consultee in local plans.

294 00:40:19.740 --> 00:40:36.640 Keith Herbert: and, you know, working to synchronize our investment with, plans, but, it's going to be very difficult for water companies to reconcile the planning and infrastructure bill with our storm overflow reduction plan. So, you know, we do a fair amount of lobbying and engagement, in the,

295 00:40:36.790 --> 00:40:41.280 Keith Herbert: In public affairs with politicians and regulators and lawmakers.

296 00:40:41.700 --> 00:40:53.380 Keith Herbert: So what's next? So, for us, we've got about 1,000 storm overflows in our region. Half of them are already hitting the government target of 10 spills per year, but half of them aren't.

297 00:40:53.380 --> 00:41:06.959 Keith Herbert: So, we've got a £1.5 billion program to do that. I emphasize that the majority of that isn't going to be on our apparatus, it's going to be taking out stormwater that doesn't need treating.

298 00:41:07.000 --> 00:41:14.809 Keith Herbert: And we publish our, all our spills on our Cleaner Rivers and Seas, and you've got a toggle on there, so you can toggle

299 00:41:14.850 --> 00:41:36.419 Keith Herbert: how and what's spilling and when, but then you can go on to the other part of it and say, well, what are we doing about it? And, you know, where are we going to invest and when? Because that's one of the things. So, all water companies have this in some way, shape, or form, and I'd encourage you to go and have a look, not only to see how frequently your local CSO activates, but also what the local water company is going to do about it and when.

300 00:41:37.650 --> 00:41:44.060 Keith Herbert: So, just a little touch on the law. The Environment Act says by 2035,

301 00:41:44.160 --> 00:42:01.440 Keith Herbert: All water companies will have proved all storm overflows discharging into bathing waters, and 75% of storm overflows discharging into high priority areas. So, by improved, the government has quantified that as 10 spills per year. So they're the magic 10 spills per year is what we're all trying to achieve.

302 00:42:01.440 --> 00:42:16.120 Keith Herbert: And then by 2050, no storm overflows will, be permitted to operate outside of unusually heavy rainfall or cause adverse ecological harm. So by 2050, all combined sewer overflows by law have to be under 10 spills per year.

303 00:42:17.710 --> 00:42:20.860 Keith Herbert: Just a word on partnership,

304 00:42:21.410 --> 00:42:42.940 Keith Herbert: most urban areas need replumbing to some extent to achieve this. So, water companies will not make this go away by themselves. In some cases, we will be able to treat more, pump more, or build tanks, but in a lot of cases, we won't be able to achieve this alone. We're going to need to work with landowners, local authorities, customers.

305 00:42:42.940 --> 00:42:47.219 Keith Herbert: And at the moment, we have no statutory rights or powers to do that.

306 00:42:47.300 --> 00:42:57.899 Keith Herbert: We cannot work on apparatus that's not ours without permission. So, you know, we need changes in behavior, legislation to ensure that this is going to be successful.

42:59.260 --> 00:43:13.189 Keith Herbert: So, if I'm just going to wrap this up, because I'm sure there's going to be lots of questions waiting for me, by law, water companies have to reduce storm overflows, and will make big improvements over the next 5 years.

308 00:43:13.260 --> 00:43:32.079 Keith Herbert: My fear is that this is just going to be seen as a water company problem, when really, it's everyone's problem, because I'm sure there's people on this call with their roofs and their driveways and conservatives draining into the vowels sewer. This isn't something that's just going to go away and the water company's going away and fix it. It's going to need a huge amount of

309 00:43:32.120 --> 00:43:36.560 Keith Herbert: Public engagement and participation. And,

310 00:43:36.560 --> 00:44:01.120 Keith Herbert: sometimes I knock on the door, and people are like, oh, you're that awful water company, you need to go away and fix it. And I'm like, well, it would really help if we could work on your property to disconnect, because that's what's causing it. So, yeah. And then the, the Section 82 of the Environment Act, which I alluded to, was the upstream and downstream monitoring of combined sewer overflows in real time, and that will allow us to quantify the impact of some of these combined sewer overflows.

311 00:44:01.230 --> 00:44:03.660 Keith Herbert: Perhaps tackle the ones that are the worst.

312 00:44:03.960 --> 00:44:09.109 Keith Herbert: And then, you know, something that I've put at the bottom, You know, this…

313 00:44:09.690 --> 00:44:26.009 Keith Herbert: I think we're already starting to see a little bit of fatigue in the issue, in the sense that when it all detonated in 21-22, it's kind of going off the boil a little bit, some of the campaign groups are running out of steam, but there's a weird sense of symbiosis between them, so really, although, you know.

314 00:44:26.570 --> 00:44:29.980 Keith Herbert: I'd take the view that us and the campaigners want the same thing.

315 00:44:30.150 --> 00:44:45.539 Keith Herbert: And we really need a bit of heat underneath it to keep driving it and drive the right solutions. So… but, I don't know, if you guys have requested me to come on this call, I'd say that, you know, you're kind of bought in, but there's a willingness to pay issue as well.

316 00:44:45.660 --> 00:45:03.330 Keith Herbert: And, do people want to pay more for their water bills to get combined sewer overflows down? Some people do. Do the majority? I don't know. You know, that's kind of off what and the Environment Agency to needs test, but, we've had many, many decades of low water bills, and then when the water bills spike up like they have done.

317 00:45:03.330 --> 00:45:16.730 Keith Herbert: My job's to make sure every penny goes in the right way, but the most people agree with me, I don't know, you know, that's a very, very difficult question to answer. But, I think for the next 5 years, at least, we've got a real good opportunity to do something about it and make some…

318 00:45:16.730 --> 00:45:21.750 Keith Herbert: Make some big improvements, so… I shall stop sharing.

319 00:45:22.000 --> 00:45:22.680 Keith Herbert: and…

320 00:45:23.350 --> 00:45:32.950 Keith Herbert: There we go. Back in the call. So, I appreciate that was very quick, and I went through quite a lot of time, but if anyone's got any questions, I'll be… I'll be happy to answer them.

321 00:45:33.300 --> 00:45:50.760 Andrew Maliphant Great Collaboration Gloucestershire: Thanks very, very much for that, Keith. Yes, there was a lot of stuff there, but I think I've certainly managed to post on some of the key points about it. And we've got some hands in the air coming already. One thing I just wanted to check out, in terms of… you put some prices against, sort of.

322 00:45:50.760 --> 00:45:57.549 Andrew Maliphant Great Collaboration Gloucestershire: circle ways in houses. Is that something the water company pays for, or is that something the householder pays for?

323 00:45:57.550 --> 00:46:00.490 Keith Herbert: Yes, we are, we are paying for it.

324 00:46:00.490 --> 00:46:00.950 Andrew Maliphant Great Collaboration Gloucestershire: Okay.

325 00:46:00.950 --> 00:46:12.350 Keith Herbert: with the view that, it's water that doesn't have to be treated into our system. So, over time, it will more than pay for itself. So, going back to my point that a cubic meter of water weighs a ton.

326 00:46:12.640 --> 00:46:16.710 Keith Herbert: And each one of these houses, 50, 60 tons, comes off it every year.

327 00:46:16.870 --> 00:46:21.210 Keith Herbert: That's water that doesn't need pumping, it doesn't need treatment chemicals.

328 00:46:21.330 --> 00:46:27.299 Keith Herbert: And, yeah, overall, it's beneficial for us to have that water that does need treating out of our system.

329 00:46:28.130 --> 00:46:39.370 Andrew Maliphant Great Collaboration Gloucestershire: Right, thank you very much. Well, I would, that sounds like a good move from a water company's point of view, and I could see how that spreads around the country. So, I would…

330 00:46:39.480 --> 00:46:55.889 Andrew Maliphant Great Collaboration Gloucestershire: Keith's happy to take some questions, and just as I said at the beginning, we're not here to harangue or have a go at water companies. We're looking at how some of the technical stuff we've heard can be absorbed and dealt with.

331 00:46:55.890 --> 00:47:00.810 Andrew Maliphant Great Collaboration Gloucestershire: Ali, I see you've got, you can… where it says react at the bottom of your screen.

332 00:47:00.810 --> 00:47:06.190 Andrew Maliphant Great Collaboration Gloucestershire: you'll be able to raise your hand there, but I acknowledge that you wanted to say something. Stuart from Essex.

333 00:47:06.380 --> 00:47:07.720 Andrew Maliphant Great Collaboration Gloucestershire: What would you like to ask?

334 00:47:08.210 --> 00:47:12.510 Cllr Stuart Withington Gt Dunmow TC, Essex: Thank you. A very interesting…

335 00:47:12.920 --> 00:47:22.610 Cllr Stuart Withington Gt Dunmow TC, Essex: talk, and quite a lot to think about. When I drive along and see these huge warehouse roofs, I think, why haven't they got solar panels on them?

336 00:47:22.860 --> 00:47:29.010 Cllr Stuart Withington Gt Dunmow TC, Essex: You put a different slant on it with, why are they draining into our… sewage system.

337 00:47:29.260 --> 00:47:35.210 Cllr Stuart Withington Gt Dunmow TC, Essex: But a question I got is, You work on an island.

338 00:47:35.520 --> 00:47:41.340 Cllr Stuart Withington Gt Dunmow TC, Essex: Why don't you, tick the storm overflow straight into the Solon?

339 00:47:41.790 --> 00:47:45.979 Cllr Stuart Withington Gt Dunmow TC, Essex: I mean, certainly in Gernard, that's, quite near the coast.

340 00:47:48.280 --> 00:47:53.899 Keith Herbert: The storm overflows do go into the Solon, unfortunately. They do.

341 00:47:54.540 --> 00:47:56.020 Keith Herbert: Far too frequently.

342 00:47:57.130 --> 00:48:00.180 Cllr Stuart Withington Gt Dunmow TC, Essex: But without being mixed with foul water.

343 00:48:00.810 --> 00:48:18.410 Keith Herbert: Well, again, if you were going to redesign the drainage of most urban areas, you would have a foul pipe for toilet sink dishwashers that would end up at the treatment works, and then you would have a stormwater sewer that would take roads, roofs, and then that would discharge out into environment.

344 00:48:18.590 --> 00:48:24.250 Keith Herbert: Unfortunately, old areas have what's called a combined system that takes everything, so…

345 00:48:24.680 --> 00:48:40.770 Keith Herbert: bit by bit, we are taking stormwater out of that combined system and putting it in the environment, but then that is a very, very difficult process to do. Very, very difficult. It's disruptive, it's expensive, so, it's how we achieve that, with everyone's best interests.

346 00:48:42.380 --> 00:48:44.860 Cllr Stuart Withington Gt Dunmow TC, Essex: But on a new estate.

347 00:48:45.990 --> 00:48:56.879 Keith Herbert: Well, again, I'd look to local planning authorities to enforce that, because we can't enforce it. So, I would say that, my challenge to all local planning authorities is

348 00:48:56.880 --> 00:49:15.750 Keith Herbert: all the new houses to be built should be the most water efficient and the most sustainable draining, because otherwise we're just going to have to take all the water out as soon as it's built, and it's just completely bonkers. So, you know, for new houses that are built, I would expect them to have sustainable drainage and not discharge their stormwater into the foul sewer.

349 00:49:17.040 --> 00:49:18.069 Cllr Stuart Withington Gt Dunmow TC, Essex: Okay, thank you.

350 00:49:18.640 --> 00:49:20.619 Andrew Maliphant Great Collaboration Gloucestershire: Thanks very much. David?

351 00:49:22.880 --> 00:49:25.870 David Newman (Blackbird Leys): You mentioned… Yeah, you mentioned that…

352 00:49:27.780 --> 00:49:32.410 David Newman (Blackbird Leys): Quite often, the loads come from people doing

353 00:49:32.710 --> 00:49:42.320 David Newman (Blackbird Leys): Upgrades to the houses, conservatories, extensions. We get lots of planning applications like that coming to our parish.

354 00:49:42.790 --> 00:49:56.349 David Newman (Blackbird Leys): Where can we get the data to find out the impact of their proposed upgrade on water, on, on, stormwater?

355 00:49:57.490 --> 00:50:09.760 Keith Herbert: It's… it's really a question for the Buildings Regulations Department at the Council, David. So, the relevant part of the building regulations is called H3.

356 00:50:10.360 --> 00:50:25.000 Keith Herbert: Which is a hierarchy. So, the first thing that the consideration should be the water, the rainwater should be introduced to the ground as close as possible to where it fell, hence why soakaways are preferable.

357 00:50:25.160 --> 00:50:34.309 Keith Herbert: But if you live in a kind of clay area, that's not always possible. So the next in the hierarchy is, you know, could you put it in a watercourse?

358 00:50:34.590 --> 00:50:42.809 Keith Herbert: Or could you put it in a stormwater sewer? And then, you know, you've got that separation, which was kind of in line with the previous question.

359 00:50:43.120 --> 00:50:52.150 Keith Herbert: And then if all else fails, then you, put it into the combined sewer, and it's our problem. Now…

360 00:50:52.560 --> 00:51:05.329 Keith Herbert: How we go about enforcing that and encouraging all these small, kind of, home improvements to do that is… is very, very difficult, and in some cases, we've actually gone to local authorities and funded

361 00:51:05.330 --> 00:51:17.269 Keith Herbert: additional building control and enforcement officers, because it's in our best interest to do that. So, the guidance and the regulations there, I wouldn't say it's consistently enforced across

362 00:51:17.270 --> 00:51:18.570 Keith Herbert: the UK.

363 00:51:18.570 --> 00:51:32.250 Keith Herbert: But that's what people should be doing, but then, you know, if you've just, you know, you're pleased with the new development and extension, you know, unfortunately, drainage isn't the first thing that people think about, unless you're me.

364 00:51:33.570 --> 00:51:42.480 Andrew Maliphant Great Collaboration Gloucestershire: Well, here we have a government, of course, planning to try to build lots and lots of more houses, so that's obviously going to be raising the stakes of what we've just been talking about.

365 00:51:42.590 --> 00:51:45.530 Andrew Maliphant Great Collaboration Gloucestershire: Thank you. Helen, Helen from Berkshire.

366 00:51:45.920 --> 00:51:54.850 Helen Pratt - Bucklebury, West Berkshire: Hello, very, very interesting. A question for you. My understanding is that sewer pipes are porous.

367 00:51:57.190 --> 00:52:02.909 Helen Pratt - Bucklebury, West Berkshire: And certainly in our area, we have a problem of water ingress.

368 00:52:03.280 --> 00:52:05.800 Helen Pratt - Bucklebury, West Berkshire: Into the porous pipes.

369 00:52:07.010 --> 00:52:13.770 Helen Pratt - Bucklebury, West Berkshire: Is there anything being done research-wise, I guess, about that.

370 00:52:15.240 --> 00:52:22.620 Helen Pratt - Bucklebury, West Berkshire: Or are there any… well, there's no easy solutions, or anything being done to resolve those types of issues?

371 00:52:24.150 --> 00:52:43.940 Keith Herbert: Yes, Helen, there is. I mean, the… the groundwater ingress, is… I mean, I've just purely talked about stormwater today, but there's another cause of spills, which is that. You tend to get it in kind of low-lying, chalky areas, and that's where the groundwater level goes up above the level of the sewer and squeezes in.

372 00:52:44.210 --> 00:52:52.340 Keith Herbert: And, really, you've got two options. You either seal all the sewers, and the way that we do that is we kind of…

373 00:52:52.620 --> 00:53:00.909 Keith Herbert: put a balloon in the pipe and blow it up and push, like, a resin material to seal the sewer. Or you treat the flow. Now,

374 00:53:00.910 --> 00:53:18.530 Keith Herbert: my job is to kind of figure out what's best for the environment and the community. Sometimes it's best to treat the flow, sometimes it's best to seal, but we've also got the added problem of the private network, because generally where you get low-lying, chalky areas, you get very pleasant properties set back from the road, so the sewer's coming in along as well.

375 00:53:18.530 --> 00:53:24.669 Keith Herbert: So, we've done both in some areas. We've sealed everything where we've had some success, or we've treated the flow. I mean.

376 00:53:24.740 --> 00:53:27.480 Keith Herbert: Personally, it's a seasonal problem.

377 00:53:27.750 --> 00:53:34.720 Keith Herbert: And, sometimes tankers have to come in and stop people from flooding, and it's a real, real nuisance. It's really, really disruptive.

378 00:53:34.720 --> 00:53:49.489 Keith Herbert: We want to get to the point with the regulators where we can use wetlands to treat the flow, and we're currently working with the Environment Agency in DEFRA to use that as an option, so we use wetlands. So, you know, long-winded way of saying, yes, we either seal the network.

379 00:53:49.520 --> 00:53:51.329 Keith Herbert: Or treat all flow.

380 00:53:52.010 --> 00:53:53.670 Helen Pratt - Bucklebury, West Berkshire: Okay, thank you.

381 00:53:53.670 --> 00:53:57.880 Andrew Maliphant Great Collaboration Gloucestershire: Thank you. Ali, Bembridge in the Art of White, I believe, yes.

382 00:53:58.160 --> 00:54:14.029 Ally De Trey: Yes, that's right. So, I was… I was interested in your comment about hydraulic models, and how you, determine where the roof runoff is going, because most people probably don't know

383 00:54:14.160 --> 00:54:33.559 Ally De Trey: whether their roof runoff is going into the sewer, or is going into soakaways or ditches. I've got a ditch down the side of my house, that can take water away. So, we need to reduce the amount of water going into

384 00:54:33.560 --> 00:54:38.690 Ally De Trey: the sewage system in Bembridge, and…

385 00:54:38.700 --> 00:54:45.789 Ally De Trey: I would be interested in how, as an individual householder, you can find out where your roof runoff goes.

386 00:54:46.450 --> 00:54:48.050 Keith Herbert: Sure, well…

387 00:54:48.490 --> 00:55:01.680 Keith Herbert: I mean, there's a number of different theories here, Ali. I mean, if you lived in New Zealand, for instance, you can't sell your property without a full drainage survey and confirmation of all of that.

388 00:55:01.680 --> 00:55:16.289 Keith Herbert: Whereas in the UK, there's varying levels of due diligence that people do on the purchase of a property. Sometimes you get a full drainage survey and you know, but, if you're really that interested, there's no harm in just tipping dye down it and finding out yourself.

389 00:55:16.290 --> 00:55:23.200 Keith Herbert: But, I mean, the curious thing about Benbridge is it does have a separate system. There's a foul, and there's a storm all over Bembridge.

390 00:55:23.200 --> 00:55:31.970 Keith Herbert: But there's clearly a lot of things connected in there which shouldn't be, and over the coming weeks, we're gonna find that out. So, yeah,

391 00:55:32.210 --> 00:55:47.769 Keith Herbert: If your water company's doing something like we're doing, it shouldn't be long, and you'll know. Other than that, I think there is an element of personal responsibility as a homeowner to know how your property drains and where the water goes, and it's always useful to know if you get any problems.

392 00:55:48.450 --> 00:55:51.200 Ally De Trey: So, what sort of dye can you use, though?

393 00:55:51.870 --> 00:56:15.830 Keith Herbert: Just sewer tracing dye. I'm sure if you type that into Amazon, you could probably get some delivered for a very reasonable price indeed, and then you just mix that with a little bit of water, and it turns a purid green, blue, orange color, and then you can just find out where it goes. Word to the wise, if you are connected to a watercourse, don't turn that watercourse bright green, because people call up and think something really bad's happened.

394 00:56:15.830 --> 00:56:18.340 Keith Herbert: From experience.

395 00:56:18.570 --> 00:56:19.380 Andrew Maliphant Great Collaboration Gloucestershire: Right.

396 00:56:20.260 --> 00:56:21.290 Ally De Trey: Okay, thanks.

397 00:56:21.300 --> 00:56:23.719 Andrew Maliphant Great Collaboration Gloucestershire: Thank you very much. Catherine?

398 00:56:27.120 --> 00:56:28.849 Andrew Maliphant Great Collaboration Gloucestershire: You're still muted, Catherine.

399 00:56:32.440 --> 00:56:34.489 Andrew Maliphant Great Collaboration Gloucestershire: There's an unmute button. There you go.

400 00:56:34.490 --> 00:56:39.979 Katherine Stott: Oh, hello, sorry about that, having a technical failure. I was just wondering,

401 00:56:40.030 --> 00:56:55.019 Katherine Stott: like, if you're… you and other water companies are planning on doing, like, much comms on this, matter, because I don't really think that the general public understand much, aside from being angry about spills, so it's like.

402 00:56:55.380 --> 00:57:07.009 Katherine Stott: there's kind of now a bit of a stigma if you're not doing your recycling properly, but there's nothing, like, nobody sneers and looks at people that have just, like, paved over their driveway, if you know what I'm saying. So just wondering if there's any comms, like, planned.

403 00:57:08.280 --> 00:57:23.329 Keith Herbert: Yeah, there is, but it's generally quite localized, Catherine, and, you know, you raise a really valid point. So, typically, when we're doing connectivity work in the area, we have a public drop-in.

404 00:57:23.520 --> 00:57:26.559 Keith Herbert: We send out an exhaustive letter drop.

405 00:57:27.140 --> 00:57:44.830 Keith Herbert: And, try and put that out as much as possible, because it's one of these things that we really need the community on side for, because people are well within their rights to say, no, really sorry, not interested, you're not digging up my drive, you're not… you're not diverting my stormwater, I don't want anything to do with it, come and tell me when it's done.

406 00:57:44.830 --> 00:57:56.580 Keith Herbert: And, you know, typical response rates are actually pretty good. So, excuse me, so for the… where we were separating out the domestic properties, we were getting a 50-60% hit rate.

407 00:57:56.710 --> 00:58:21.140 Keith Herbert: Which was… which I considered to be really good. And the majority of people didn't say no, the majority of people was just like, well, I've just had my driveway done, I really don't want you digging it up. And that's fine, you know, we're not trying to get every single property out, we're just trying to get most of them out. So, but yeah, just like everything we do, there's so much scrutiny in it, and we've got to get the community onside and on board, and…

408 00:58:21.140 --> 00:58:28.579 Keith Herbert: You know, some of the things that we've thought about is, well, tell you what, why don't we just, you know, get a lump sum and donate it to a charity if we get…

409 00:58:28.580 --> 00:58:53.119 Keith Herbert: the CSO skills down below a certain level, so we can kind of work with the community. You know, we go and, you know, build a nice park for the kids, or, you know, redo a town center or something, because, you know, we're not just going to get this on our own, so, you know, that's why we've got a whole partnership team now just doing that kind of stuff, to really kind of pave the way for people to accept the solution that we put

410 00:58:53.120 --> 00:58:53.950 Keith Herbert: pose.

411 00:58:55.100 --> 00:58:55.800 Andrew Maliphant Great Collaboration Gloucestershire: Wow.

412 00:58:56.150 --> 00:58:56.950 Andrew Maliphant Great Collaboration Gloucestershire: Right.

413 00:58:57.750 --> 00:59:01.289 Andrew Maliphant Great Collaboration Gloucestershire: Thanks very much for that. Great, Sue, Sue Burton.

414 00:59:01.440 --> 00:59:19.909 Sue Burton: Okay, got a few questions, thank you. First of all, like, can you explain further what you mean about the die? Because, like, where I live, there are no obvious watercourses. I'm in a road with a number of houses, tarmac down the high road,

415 00:59:20.330 --> 00:59:31.309 Sue Burton: Do I presume that my water is going into the foul water? It's an old property, an old road? What do I presume?

416 00:59:31.620 --> 00:59:37.049 Keith Herbert: I think some… Somewhere on your property, there will be, an inspection cover.

417 00:59:37.240 --> 00:59:40.449 Keith Herbert: That you can lift and see the pipes underneath.

418 00:59:40.700 --> 00:59:45.310 Keith Herbert: And, typically what we do is we tip-dye down the downpipes.

419 00:59:45.400 --> 00:59:55.120 Keith Herbert: And find out where that goes. Sometimes we can do it on the property, sometimes we can lift the covers in the road and prove it that way.

420 00:59:55.190 --> 01:00:11.370 Keith Herbert: So, you know, I wouldn't recommend lifting covers in the road, because that's the water companies, and you'll need traffic management. You don't want to get hit by a car, or anyone drive down it, but on your property, if you're not confident doing it yourself, there's plenty of contractors that could do that for you.

421 01:00:11.660 --> 01:00:15.040 Sue Burton: What sort of contractor would you be thinking of, Keith?

422 01:00:15.350 --> 01:00:17.329 Keith Herbert: I can't recommend specific ones.

423 01:00:17.330 --> 01:00:21.139 Sue Burton: No, I mean, but what are they called? Are we talking about a plumber? What am I talking about?

424 01:00:21.140 --> 01:00:27.620 Keith Herbert: No, just general drainage contractors. So, you know, if you typed in drainage survey and the.

425 01:00:27.620 --> 01:00:28.189 Sue Burton: Oh, okay.

426 01:00:28.190 --> 01:00:38.240 Keith Herbert: kind of where you live, there'd be plenty of people that would come to your property and do that. And, I would also add that most water companies offer a rebate

427 01:00:38.240 --> 01:00:54.769 Keith Herbert: I wouldn't get too excited. It's about 20, 30 pounds a year, but they offer a rebate if your stormwater doesn't go into their system. So, you know, we're working to get that increase to try and incentivize people to do, you know, what you're thinking about, and diverting their stormwater somewhere else.

428 01:00:55.370 --> 01:01:04.959 Sue Burton: Right, brilliant. So my other mother thing, bringing back… I was also going to ask you about comms, because I,

429 01:01:05.520 --> 01:01:21.090 Sue Burton: you know, I'm… I can't… I live in Battle in East Sussex, nice and high up. I can't believe… I can't believe that we'll be high on your list for looking at our community because of our location.

430 01:01:21.090 --> 01:01:35.179 Sue Burton: But there are things that residents can do, and one is the three P's, and then, of course, there's the driveways, extensions, and saving water. And in the past, there's been, like, you could contact

Sue Burton: I'm not sure if it's your water company, but our local water company, and get a slow shower head and bits and bobs. And I think that the prevention and education of people widely is to be encouraged. You know, all of us probably have our connections with our parishes, and we can send stuff out.

432 01:01:57.390 --> 01:02:02.750 Sue Burton: you know, remind people of the three P's. If you're thinking of doing a driveway.

433 01:02:02.750 --> 01:02:08.769 Sue Burton: The benefits of doing one that has drainage, you know, has, whatever you call it, you know, not a…

434 01:02:08.790 --> 01:02:19.450 Sue Burton: has a sustainable surface, you know, and I think anything that we can get that is easy for us to distribute to our residents would be really helpful.

435 01:02:19.960 --> 01:02:38.509 Keith Herbert: No, I agree, and, you know, most water companies, Southern Water included, have outreach schemes to, you know, encourage people for better water usage, because as you say, education is a lot better than anything else, and people turning off the tap when they brush their teeth, and filling up the dishwasher, and all of that stuff makes a big impact. Yeah.

436 01:02:39.350 --> 01:02:48.819 Sue Burton: I suppose what I'm saying is, can we move it on to extensions, driveways, you know, because in the past, it's mainly about water saving.

437 01:02:49.410 --> 01:03:08.060 Keith Herbert: Yeah, and, you know, this comes to the really difficult thing, is that water companies do not have a say, really, in the planning process, especially not for smaller ones. So, our efforts are targeted towards planning officers, building control, and local tradespeople to try and A get the connection right, but B, make sure that

438 01:03:08.250 --> 01:03:20.340 Keith Herbert: people aren't just paving over land that currently soaks water away, and it now runs off into our system. So, we are working with local authorities, but… but to be brutally honest, Sue, we need help.

439 01:03:20.600 --> 01:03:37.139 Sue Burton: Yeah, well, I'm really pleased you've been here today. It's another segment in knowing about water, and how we can manage it, and better, and the clean water and all that. It's always another segment to understanding the picture, and what we can do.

440 01:03:38.270 --> 01:03:39.570 Keith Herbert: Thank you, Steve. Thank you.

441 01:03:40.020 --> 01:03:48.930 Andrew Maliphant Great Collaboration Gloucestershire: Yeah, I think some… some things in terms of how we share good practice with people is something that the Great Collaboration is set up to do, and that's… it's…

442 01:03:49.000 --> 01:03:59.029 Andrew Maliphant Great Collaboration Gloucestershire: Partly it's the way you tell them, but also, I think David's had to leave the meeting, but if there are… is there information, tap information, data that can help.

443 01:03:59.030 --> 01:04:10.390 Andrew Maliphant Great Collaboration Gloucestershire: underpin some of these messages. That's very good, too. So, that's all very… that's all that needs to come together. Andrew, Andrew from the Isle of Wight, you've got your hand up.

444 01:04:13.860 --> 01:04:16.259 Andrew Maliphant Great Collaboration Gloucestershire: You're still muted, Andrew.

445 01:04:18.180 --> 01:04:20.209 Andrew No Poo at the point iow: So, is that better? Hello?

446 01:04:20.210 --> 01:04:20.720 Andrew Maliphant Great Collaboration Gloucestershire: Yep, yep.

447 01:04:20.720 --> 01:04:21.260 Keith Herbert: Hello.

448 01:04:21.260 --> 01:04:36.720 Andrew No Poo at the point iow: Thanks, Keith, for coming today, and perhaps a little apology for a recent bashing we've given you from Bembridge on our CSO issue. I think there it's quite difficult to,

449 01:04:37.080 --> 01:04:55.190 Andrew No Poo at the point iow: I appreciate the efforts that Southern Water are making, but then, equally, we see, sort of, CSO discharges going up all the time. But I wanted to… you've slipped into your presentation about, people perhaps paying more to sort this out, and that we've had decades of low bills.

450 01:04:55.190 --> 01:05:01.670 Andrew No Poo at the point iow: I just did want… just want to check your… know your justification on, on…

451 01:05:02.380 --> 01:05:08.920 Andrew No Poo at the point iow: Having decades of low bills, when we've had decades of excess dividends, loan interest payments.

452 01:05:08.920 --> 01:05:09.639 Andrew Maliphant Great Collaboration Gloucestershire: Good.

453 01:05:09.640 --> 01:05:10.929 Andrew No Poo at the point iow: and so on.

454 01:05:11.280 --> 01:05:11.555 Andrew Maliphant Great Collaboration Gloucestershire: Oh.

455 01:05:11.830 --> 01:05:14.170 Keith Herbert: It's fine, I mean, I can… I can tackle that, that's fine.

456 01:05:14.170 --> 01:05:14.610 Andrew Maliphant Great Collaboration Gloucestershire: Okay.

457 01:05:14.610 --> 01:05:19.380 Keith Herbert: Southern Water hasn't paid a dividend since… 2017.

458 01:05:19.540 --> 01:05:29.120 Keith Herbert: So, again, things like this, the facts are important, and the whole argument around… nationalization versus…

459 01:05:29.270 --> 01:05:41.359 Keith Herbert: private ownership. I mean, it's not something we're going to solve on this call, but what I would add is that when Macquarie took over Southern Water, they pumped in about $1.5 billion.

460 01:05:41.720 --> 01:05:48.789 Keith Herbert: And if Thames Water ever is nationalized, the customers will see that it's then in competition with

461 01:05:48.920 --> 01:05:52.270 Keith Herbert: Schools, healthcare, defense.

462 01:05:52.690 --> 01:05:56.079 Keith Herbert: And going back to the start of my presentation.

463 01:05:56.190 --> 01:06:12.609 Keith Herbert: it hasn't been the sexy one that's got all the funding. So, again, it's not really for the content of this meeting, but I can't see a world in where customers are going to get a better service if it's nationalized, purely because it's going to be in competition with anything else.

464 01:06:12.610 --> 01:06:26.170 Keith Herbert: And most public services are almost back to the statutory function, where the ability to generate capital is one of the good things that we get to do. So, you know, the $1.5 billion program that I'm doing at the moment.

465 01:06:26.390 --> 01:06:42.500 Keith Herbert: I've got to make sure that we strike while the iron's hot, and while there's a bit of focus, we get all that good work done. I couldn't see something like that happening internationally. And then all you've got to do is look north at Scotland, which is still under government ownership.

466 01:06:42.680 --> 01:06:51.050 Keith Herbert: And there's not really much of a row in Scotland, because they haven't got alarms on their combined sewer overflows. So one could argue that

467 01:06:51.050 --> 01:06:54.429 Keith Herbert: The high levels of transparency around what we do.

468 01:06:54.430 --> 01:07:14.609 Keith Herbert: has generated that interest. And so this whole thing about England being the dirty one of Europe, I, you know, I struggle with that. You know, all of the world's cities have combined sewer overflows, because they're combined systems, most of them anyway, especially the historic ones. You know, look at Paris, where the, the swim was postponed, because there were CSOs in the Seine.

469 01:07:14.610 --> 01:07:17.339 Keith Herbert: But in Scotland.

470 01:07:17.340 --> 01:07:35.609 Keith Herbert: there's not alarms on all the CSOs, so you can't have any discourse about them. You can't run reports on how frequently they are, where in England, you can absolutely do that. You can just go on any app, and you can find out how often they go for, for how long, etc. So, you know, I think that that's the debate that's going to rumble on, but,

471 01:07:35.610 --> 01:07:39.379 Keith Herbert: Yeah, it's not something that we're going to solve here, unfortunately.

472 01:07:39.760 --> 01:07:41.579 Andrew No Poo at the point iow: I didn't look too much. Thank you for that, thank you.

473 01:07:42.390 --> 01:07:43.439 Andrew Maliphant Great Collaboration Gloucestershire: Thank you very much.

474 01:07:44.090 --> 01:07:57.520 Andrew Maliphant Great Collaboration Gloucestershire: Wow, well, I'm certainly toasting a lot more. I've just made a note to myself, turn off the turn of the tap when I'm cleaning my teeth, you know, all these little things. One thing that did come to me, I know in some ways,

475 01:07:57.520 --> 01:08:09.129 Andrew Maliphant Great Collaboration Gloucestershire: there's another organization called Communities Prepared, and they're saying, well, we've got to deal with floods, but then that's… it's not just about getting rid of the water, because there'll be droughts when you actually want some of that water, how you can use it.

476 01:08:09.130 --> 01:08:15.199 Andrew Maliphant Great Collaboration Gloucestershire: And I know some… in some parts of the country, there are people funding, you know, water butts and so forth, and

477 01:08:15.200 --> 01:08:31.439 Andrew Maliphant Great Collaboration Gloucestershire: I have a dream, is that local authorities, as well as providing green bins for the rubbish, can provide water butts to the places that were useful. I mean, that's a small thing, that's a very localized thing, but I mean, I don't know how…

478 01:08:31.720 --> 01:08:40.269 Andrew Maliphant Great Collaboration Gloucestershire: in the great scheme of things, Keith, is that… is that… would that… how much impact would that make, you think? Is that an important thing to everybody at Waterbutts?

479 01:08:41.020 --> 01:08:49.539 Keith Herbert: Well, from a water efficiency perspective, they're fantastic. In terms of stopping water hitting our system, they're quite low down the pecking order.

480 01:08:49.540 --> 01:09:07.529 Keith Herbert: Because, you know, even the biggest water books only take 200, 300 liters, so they fill up quite quickly. And then during the course of the winter, they tend to stay full, so we need to design a mechanism so they slowly drain down and are sensitive to the network. I mean, we have… we have handed out many, many thousands of them.

481 01:09:07.529 --> 01:09:09.410 Keith Herbert: And they do make an impact.

482 01:09:09.479 --> 01:09:11.090 Keith Herbert: But,

483 01:09:11.200 --> 01:09:34.839 Keith Herbert: you know, things get moved around people's garden, they get blocked, and they get used for other things, so it's not really the best sustainable solution. But also, you know, the areas I tend to work are kind of older Victorian townhouse areas that are combined, and, you know, it's a, you know, trying to get them in is very, very difficult. You know, people don't want a big, ugly green water boat outside their property, but anyway,

484 01:09:34.870 --> 01:09:39.150 Keith Herbert: I do apologize, I have a 12 o'clock meeting with a hard cut-off.

485 01:09:39.279 --> 01:09:45.439 Keith Herbert: But I would just like to say thanks for having me, thanks for the interesting questions, and I hope you got a lot out of it.

486 01:09:46.180 --> 01:09:59.309 Andrew Maliphant Great Collaboration Gloucestershire: Great, many thanks, Keith. Brilliant. It's great to have some of that background and data, and as and when we might need some more technical information to feed up some communications, your phone may well ring. Many thanks for giving us all of those details.

487 01:09:59.310 --> 01:10:00.429 Keith Herbert: Cheers, guys, bye bye.

488 01:10:00.430 --> 01:10:02.470 Sue Burton: Thank you, Kate. Thank you.

489 01:10:02.610 --> 01:10:04.870 Cathy Wynne: Yep, yep, very good. Interesting.

490 01:10:05.150 --> 01:10:08.170 Andrew Maliphant Great Collaboration Gloucestershire: Well, that was a fun thing, wasn't it? My word.

491 01:10:08.790 --> 01:10:14.129 Andrew Maliphant Great Collaboration Gloucestershire: a rare opportunity, I suspect, to actually hear it from,

492 01:10:14.270 --> 01:10:19.120 Andrew Maliphant Great Collaboration Gloucestershire: a water company, in an open forum like this, so there we go.

493 01:10:19.290 --> 01:10:20.460 Sue Burton: Can I speak?

494 01:10:20.760 --> 01:10:21.850 Andrew Maliphant Great Collaboration Gloucestershire: Sue, go for it.

495 01:10:21.850 --> 01:10:30.499 Sue Burton: Yeah, so I went to, I think it must have been pre-COVID, a talk with our local water company.

496 01:10:30.760 --> 01:10:46.009 Sue Burton: And they talked the same bit about getting… finding out who was wrongly connected and the extensions. They were talking about that then. And it sounds like, I missed the beginning, that that work has really stepped up

497 01:10:46.010 --> 01:10:54.949 Sue Burton: in bigger communities are being challenged, etc. I… so I think they are… they are coming along.

498 01:10:54.950 --> 01:11:11.189 Sue Burton: But they're… they're now… it seems to be… the bit… the question I didn't ask, because I'm not very knowledgeable on it, is where does this fit in with this new… the planning legislation, the NFPF, whatever it is, the National Freight.

499 01:11:11.190 --> 01:11:12.440 Andrew Maliphant Great Collaboration Gloucestershire: Planning Policy Framework, yeah.

500 01:11:12.440 --> 01:11:19.640 Sue Burton: Yeah, so is there some hope to help the connections in that? Does anybody know?

501 01:11:19.640 --> 01:11:26.500 Andrew Maliphant Great Collaboration Gloucestershire: Well, that's a good question. The present government has already changed the national planning framework once.

502 01:11:26.570 --> 01:11:35.240 Andrew Maliphant Great Collaboration Gloucestershire: And it's busy changing it again, and I think sometime this summer we're going to get to see it. So we can't yet say what the answer is.

503 01:11:35.310 --> 01:11:40.529 Andrew Maliphant Great Collaboration Gloucestershire: the… I mean, the current government seems to be desperate to build houses almost at any cost, you know.

504 01:11:40.560 --> 01:11:56.100 Andrew Maliphant Great Collaboration Gloucestershire: In the previous version of the National Planning Policy Framework, there was a footnote saying, P.S. be careful of prime agricultural land. That's been taken out by this government, you know? And this is very relevant to our 180-house application in my village.

505 01:11:56.100 --> 01:12:01.610 Andrew Maliphant Great Collaboration Gloucestershire: But I think that the idea that the local planning authorities, as well as

506 01:12:01.630 --> 01:12:09.100 Andrew Maliphant Great Collaboration Gloucestershire: the National Planning Performance Group can have an impact on this. I don't think that is well known around the country.

507 01:12:09.180 --> 01:12:21.349 Andrew Maliphant Great Collaboration Gloucestershire: And I'm… I don't know, I'm going to have to look this up now, as to what the previous National Planning Policies Framework said around that particular issue.

508 01:12:22.600 --> 01:12:35.449 Andrew Maliphant Great Collaboration Gloucestershire: how to develop building regulations which insist on certain things. I mean, the last Conservative government was going to bring in something last year about that. That seems to have got postponed. I don't think that's happened yet.

509 01:12:35.570 --> 01:12:45.420 Andrew Maliphant Great Collaboration Gloucestershire: So I think in terms of… there are things we can always be alert to locally. How we change things nationally, in a positive way.

510 01:12:45.530 --> 01:12:48.769 Andrew Maliphant Great Collaboration Gloucestershire: I think that… that is a very good question.

511 01:12:49.010 --> 01:13:01.609 Andrew Maliphant Great Collaboration Gloucestershire: for myself, I decided decades ago not to get involved in national politics, but to work with communities. But sometimes you have to poke, you know, bang on the ceiling and send some messages upwards.

512 01:13:01.750 --> 01:13:08.329 Andrew Maliphant Great Collaboration Gloucestershire: But I will be as interested as you, Sue, to find out what the latest MBPF has to say.

513 01:13:09.150 --> 01:13:21.989 Sue Burton: Yeah, because that could help it a lot, because at the moment, they're basically dealing with the outcome of what we have, rather than being supported to reduce the problem, basically.

514 01:13:22.130 --> 01:13:38.059 Andrew Maliphant Great Collaboration Gloucestershire: And this is where it comes back to, you know, the way we tell them, what's the languages, what are the messages, how we get those out there. We tend to get a lot of negative stuff in the press one way or another. How do we gather the best, you know, the good practice? How do we put that in terms that people can accept?

515 01:13:38.090 --> 01:13:54.069 Andrew Maliphant Great Collaboration Gloucestershire: And how do we, how we… how do we get the message across so that people can feel enabled and empowered, if you like, to do something? There's this people's emergency briefing film going around the country. I know that's been shown in Bembridge in particular. I don't know if you were there, Ali.

516 01:13:54.070 --> 01:13:59.629 Andrew Maliphant Great Collaboration Gloucestershire: But, hopefully that can be also a bit of a springboard to people doing some…

517 01:13:59.640 --> 01:14:03.269 Andrew Maliphant Great Collaboration Gloucestershire: more things locally. Did you go to any of those film screenings, Ellie?

518 01:14:03.740 --> 01:14:19.140 Ally De Trey: Yes, I did. I went to… I've been to three, I think, now, and we've put together an action group, two, all taking on various tasks, so I seem to have taken on the task of,

519 01:14:19.970 --> 01:14:28.649 Ally De Trey: getting allotments in the village, and building… helping with food security, because I personally think that,

520 01:14:29.480 --> 01:14:36.429 Ally De Trey: Yeah, that's important, and for us, we don't really have much land available, because it's all RSPB reserve.

521 01:14:37.210 --> 01:14:39.609 Andrew Maliphant Great Collaboration Gloucestershire: Right, is that right? Okay, yeah.

522 01:14:39.790 --> 01:14:46.820 Andrew Maliphant Great Collaboration Gloucestershire: I keep saying to Graham, I will come to the Isle of Wight one day, but I enjoyed it thoroughly the last time I went for a long time ago.

523 01:14:46.960 --> 01:15:01.389 Andrew Maliphant Great Collaboration Gloucestershire: Yes, allotments, I'm big on that, Mr. Allotments, that's me. See what else we can do about stuff. What I'm beginning to talk about, think about with other organizations that are also trying to share and gather and share good practice, is

524 01:15:01.890 --> 01:15:16.900 Andrew Maliphant Great Collaboration Gloucestershire: Can we pull together stuff in a format that, you know, if you're in a community, how do you assess what your risks and concerns are? How do you assess what your opportunities are? What are the things you need to look at? Water's one of them, clearly. Food is another.

525 01:15:16.900 --> 01:15:25.760 Andrew Maliphant Great Collaboration Gloucestershire: I haven't yet managed to find the document which explains why the current government is desperate to build all these hundreds of houses.

526 01:15:25.830 --> 01:15:39.680 Andrew Maliphant Great Collaboration Gloucestershire: And I used to be able to find such a thing, I haven't found it yet. What's the rationale behind it? But to put roof over people's heads, and they don't… and they just make the water system worse, and they can't… they haven't got enough to eat, sounds to be a bit short-sighted.

527 01:15:39.780 --> 01:15:41.800 Andrew Maliphant Great Collaboration Gloucestershire: This is me on my soapbox now.

528 01:15:41.800 --> 01:15:42.230 Cathy Wynne: That's good.

529 01:15:42.230 --> 01:15:52.570 Andrew Maliphant Great Collaboration Gloucestershire: government's not… historically not been very well joined up, and it hasn't helped. I think, that government departments vie with each other for money from comprehensive spending reviews.

530 01:15:52.710 --> 01:16:03.979 Andrew Maliphant Great Collaboration Gloucestershire: So there are things that we need to think about at a national level. At the moment, we've got five political parties vying for people's votes.

531 01:16:03.990 --> 01:16:13.309 Andrew Maliphant Great Collaboration Gloucestershire: I don't think any of them are really playing the sort of environment card at the moment. They're all looking at other ways of trying to get into… get people to vote for them, which is somewhat depressing.

532 01:16:13.460 --> 01:16:22.719 Andrew Maliphant Great Collaboration Gloucestershire: But, what's the… what's the phrase? Keep calm and carry on, I think. But I think there's a message about keep calm and work differently, because…

533 01:16:22.930 --> 01:16:29.290 Andrew Maliphant Great Collaboration Gloucestershire: The world is changing around us, we need to help people where we can, but also to think about what is the…

534 01:16:29.440 --> 01:16:45.250 Andrew Maliphant Great Collaboration Gloucestershire: what is the best plan going forward? And having greater local resilience so that communities do come together and talk about this stuff, and these film screenings does provide an opportunity for that. That's the opportunity we've got at the moment. Lots of those screenings happening all around the country.

535 01:16:46.400 --> 01:16:54.029 Ally De Trey: Yeah, I think that water and food go together, though. Certainly, the hosepipe vans we've had the last few years, we need to look at

536 01:16:54.140 --> 01:16:56.140 Ally De Trey: preserving

537 01:16:56.570 --> 01:17:06.859 Ally De Trey: the rainwater that we get, and finding… finding access to it to use for growing food, basically. They're very closely linked.

538 01:17:07.770 --> 01:17:08.630 Andrew Maliphant Great Collaboration Gloucestershire: Yes, indeed.

539 01:17:09.350 --> 01:17:10.400 Andrew Maliphant Great Collaboration Gloucestershire: Indeed.

540 01:17:11.380 --> 01:17:12.200 Andrew Maliphant Great Collaboration Gloucestershire: Good.

541 01:17:12.310 --> 01:17:15.520 Andrew Maliphant Great Collaboration Gloucestershire: You've been listening carefully, Cathy. Have you got any thoughts about

542 01:17:16.240 --> 01:17:19.890 Andrew Maliphant Great Collaboration Gloucestershire: I can see you thinking there. See you thinking.

543 01:17:19.890 --> 01:17:25.970 Cathy Wynne: See the bubbles coming out of my head, yeah. It's all very,

544 01:17:27.000 --> 01:17:31.690 Cathy Wynne: very involved, isn't it? One thing feeds onto another, that links into the other.

545 01:17:31.980 --> 01:17:41.379 Cathy Wynne: Keith did talk about the spillages. In my instance, where we are in Kent, we get spillages when there isn't rain.

546 01:17:41.860 --> 01:17:50.260 Cathy Wynne: So, you know, there is a problem that we're getting, even when the sewage isn't capable of coping even without

547 01:17:50.370 --> 01:17:51.950 Cathy Wynne: excess rainwater.

548 01:17:52.190 --> 01:17:56.180 Cathy Wynne: But there is a large area, a lot of the building was…

549 01:17:56.320 --> 01:17:58.430 Cathy Wynne: Most of the building in the area.

550 01:17:59.600 --> 01:18:04.189 Cathy Wynne: A large estate was built 70-odd years ago, and it is all combined.

551 01:18:05.610 --> 01:18:08.160 Cathy Wynne: Sewerage, and it is a big issue.

552 01:18:08.380 --> 01:18:15.060 Cathy Wynne: But more importantly at the moment, I think people have touched on it, is that, it's the infilling, is…

553 01:18:15.200 --> 01:18:19.870 Cathy Wynne: A lot of the bigger, older houses in the areas have got large gardens that are being

554 01:18:19.980 --> 01:18:24.980 Cathy Wynne: Hived off, and 4 houses here, 6 houses here, 10 houses there.

555 01:18:25.120 --> 01:18:31.230 Cathy Wynne: And none of those, at the parish, have we been able to put any

556 01:18:31.550 --> 01:18:44.069 Cathy Wynne: made any difference with getting proper drainage for those properties that is not going into the main sewerage. And it's really, really disappointing that our local planners are… seem to be absolutely

557 01:18:45.080 --> 01:18:46.220 Cathy Wynne: Adverse.

558 01:18:46.420 --> 01:18:52.130 Cathy Wynne: And have stated in planning meetings that flooding is not an issue that they take into account.

559 01:18:52.380 --> 01:18:53.809 Cathy Wynne: Which is absolutely…

560 01:18:53.960 --> 01:18:55.589 Andrew Maliphant Great Collaboration Gloucestershire: That's pretty depressing.

561 01:18:55.590 --> 01:18:56.930 Cathy Wynne: Very depressing.

562 01:18:56.930 --> 01:19:07.720 Andrew Maliphant Great Collaboration Gloucestershire: I mean, good lord. I had somebody once, or whatnot long ago, say to me, oh, we're not worried about flooding because we live on a hill. Well, let's just say, just to hope you don't get cut off from your services by water around you.

563 01:19:07.720 --> 01:19:08.979 Cathy Wynne: Wound you, yes, yes.

564 01:19:08.980 --> 01:19:12.110 Andrew Maliphant Great Collaboration Gloucestershire: We hadn't thought of that, they said.

565 01:19:12.320 --> 01:19:16.859 Cathy Wynne: Having lived on a hill, actually, and been flooded because the water raced down through.

566 01:19:17.460 --> 01:19:19.810 Cathy Wynne: front door and out the back door, going down the hill.

567 01:19:19.810 --> 01:19:22.070 Andrew Maliphant Great Collaboration Gloucestershire: Oh my god. Oh, I'm excited about this.

568 01:19:22.090 --> 01:19:25.819 Cathy Wynne: You can get it everywhere. But, present moment, I live in a…

569 01:19:25.990 --> 01:19:32.430 Cathy Wynne: the bottom end of a valley, but it's on very, very heavy clay, so it doesn't drain, and we get…

570 01:19:34.850 --> 01:19:43.250 Andrew Maliphant Great Collaboration Gloucestershire: I think that's another thing, if people are assessing the issue, risk, opportunity, and areas, the nature of your soil is a factor, isn't it?

571 01:19:43.250 --> 01:19:47.120 Cathy Wynne: It's a big factor. Soakaways really just don't…

572 01:19:47.340 --> 01:19:49.840 Cathy Wynne: work for us. I mean, we,

573 01:19:50.030 --> 01:19:56.110 Cathy Wynne: A number of years ago now, the parish paid for a… A bore. Hold down.

574 01:19:56.470 --> 01:20:15.170 Cathy Wynne: a particular area to try and get some drainage in an area, and it went down to, different areas of types of clay. It's wieldon clay, or this clay, or that clay. Right. It was over, I think down 50 meters down before it got to anything other than very heavy solid clay.

575 01:20:15.430 --> 01:20:17.440 Cathy Wynne: So it was,

576 01:20:18.540 --> 01:20:24.039 Cathy Wynne: trying to dig a soak away 50 feet down is not great. Well, I was gonna say, yeah. Absolutely impractical.

577 01:20:24.040 --> 01:20:25.400 Andrew Maliphant Great Collaboration Gloucestershire: Where does it go from there, you know?

578 01:20:25.400 --> 01:20:27.280 Cathy Wynne: Yes. Yeah.

579 01:20:27.280 --> 01:20:28.590 Andrew Maliphant Great Collaboration Gloucestershire: But.

580 01:20:28.650 --> 01:20:35.849 Cathy Wynne: It's, interesting to hear what the Southern Water… because a number of years ago.

581 01:20:36.150 --> 01:20:48.119 Cathy Wynne: how their attitude has actually changed, sort of, pre-pandemic, our flood forum were meeting with Southern Water, who are our local, suppliers. Well, for drainage, anyway.

582 01:20:48.530 --> 01:20:55.940 Cathy Wynne: And we were wanting to put a campaign on to get people to have water baths, that sort of thing, and they weren't interested at that point in time.

583 01:20:56.800 --> 01:21:00.570 Cathy Wynne: So that attitude has really changed over the last,

584 01:21:01.100 --> 01:21:10.779 Cathy Wynne: well, probably 8 years now rather than 5, but, well pre-pandemic, which is good to hear. I'm pleased that that's, I'm very interested if they're gonna…

585 01:21:11.170 --> 01:21:14.129 Cathy Wynne: Be willing to… pay for,

586 01:21:14.460 --> 01:21:19.620 Cathy Wynne: resurfacing and that sort of… some of the larger areas in the air. That could help quite considerably.

587 01:21:19.740 --> 01:21:23.019 Cathy Wynne: So it's been very interesting. Thank you for putting it on.

588 01:21:23.300 --> 01:21:25.169 Andrew Maliphant Great Collaboration Gloucestershire: Oh, no, that's fine.

589 01:21:25.170 --> 01:21:25.750 Cllr Stuart Withington Gt Dunmow TC, Essex: I must cut.

590 01:21:26.100 --> 01:21:26.909 Andrew Maliphant Great Collaboration Gloucestershire: We've got to do.

591 01:21:26.910 --> 01:21:27.410 Cathy Wynne: Anyway.

592 01:21:27.410 --> 01:21:29.380 Andrew Maliphant Great Collaboration Gloucestershire: session, and we'll see you all next time.

593 01:21:29.380 --> 01:21:30.990 Cathy Wynne: Yep, thank you. Bye-bye.

594 01:21:32.130 --> 01:21:34.330 Andrew Maliphant Great Collaboration Gloucestershire: Cheers to it. Cheers, Cathy. Cheers soon.

595 01:21:36.350 --> 01:21:39.610 Sue Burton: I must go… I must go, too. Thanks so much!

596 01:21:39.610 --> 01:21:41.270 Andrew Maliphant Great Collaboration Gloucestershire: Okay, Sue, look after yourself.

597 01:21:41.440 --> 01:21:44.739 Sue Burton: Rabbi, I must come to the Isle of Wight, too.

598 01:21:45.450 --> 01:21:50.560 Andrew Maliphant Great Collaboration Gloucestershire: Okay, yes, I think we should. I've told they've got a brewery there, so that would be interesting.

599 01:21:50.560 --> 01:21:53.999 Sue Burton: I know, I want a guided tour of all these projects.

600 01:21:54.000 --> 01:21:57.990 Andrew Maliphant Great Collaboration Gloucestershire: Yes, indeed. Bye now. Lots going on. Take care.

601 01:21:57.990 --> 01:21:58.540 Sue Burton: Bye.

---

Markdown version of the presentation:

Storm Overflows

Great Collaboration Presentation

---

Slide 2 – Background and Context

Background and Context

• CSOs are automated, regulated and protect something.

• If water companies only had to treat foul flow, CSOs wouldn't be required.

• The root cause of CSO activation is excess flow.

• Networks have a finite capacity.

• Most of the work is going to have to take place on third-party apparatus.

• The actual impact of CSOs is very poorly understood.

• Lack of factual information is affecting recruitment, retention and morale.

---

Slide 3 – Our History

Our History

Date	Milestone
2021	Clean Rivers and Seas Task Force established
2022	Pathfinder projects set up with £7 million funding
Apr 2023	Accelerated funding of £35 million agreed
Nov 2023	Clean Rivers and Seas Plan launched
Mar 2024	Additional accelerated funding of £10 million agreed
Now	Starting AMP8 work early, focusing on priority areas
2025–2030	Continue delivering overflow reduction throughout AMP8

---

Slide 4 – Removing Rainfall Dependency

Removing Rainfall Dependency

A graph illustrating the relationship between rainfall and sewer performance, demonstrating the aim of reducing storm overflow dependence on rainfall events.

---

Slide 5

A spreadsheet ranking Isle of Wight overflow assets by:

• Spill frequency

• Overflow probability at different rainfall intensities

• Seasonality

• Largest influencing factor

• Infrastructure severity

• Rainfall severity

The table is colour-coded to highlight priority assets.

---

Slide 6 – CSO Targeting

CSO Targeting

Maps illustrating the targeting methodology used to prioritise Combined Sewer Overflow (CSO) interventions across catchments.

---

Slide 7 – Proving with Connectivity

Proving with Connectivity

Illustrates sewer connectivity mapping together with field investigations to verify how properties are connected to the sewer network.

---

Slide 8 – Step 1: Optimisation

Step 1 – Optimisation

Reconfiguring permits and existing sites to help reduce storm overflows.

Pathfinder Process

1. Optimising infrastructure

2. Storm connections

3. Household SuDS

4. Non-household SuDS

5. Highway schemes

---

Slide 9 – Fairlee Performance

Fairlee performance over 10,000 m³

The graph compares system performance before and after optimisation, highlighting:

• Spills caused by inability to return.

• Spills subsequently avoided following optimisation.

---

Slide 10 – Step 2: Storm Connections

Step 2 – Storm Connections

Redirecting surface water that has been connected into the foul/combined sewer.

Pathfinder Process

1. Optimising infrastructure

2. Storm connections

3. Household SuDS

4. Non-household SuDS

5. Highway schemes

Slide 11 – Step 3: Household

Step 3 – Household

Rolling out "slow the flow" measures at scale on properties in our catchments.

Pathfinder Process

1. Optimising infrastructure

2. Illegal connections

3. Household SuDS

4. Non-household SuDS

5. Highway schemes

The slide illustrates examples including:

• Permeable driveways

• Rain gardens

• Water butts

• Household drainage modifications

• Property-scale SuDS installations

---

Slide 12 – Step 4: Non-Household SuDS

Step 4 – Non-Household SuDS

Targeting large roof areas with "slow the flow" measures to deliver impact.

Pathfinder Process

1. Optimising infrastructure

2. Illegal connections

3. Household SuDS

4. Non-household SuDS

5. Highway schemes

Examples shown include:

• Industrial buildings

• Large commercial roofs

• Care-home planter installations

• Mapping roofs greater than 300 m².

---

Slide 13 – Step 5: Highway Schemes

Step 5 – Highway Schemes

With significant volumes of surface water originating from public highways, highway design becomes an essential part of the solution.

Pathfinder Process

1. Optimising infrastructure

2. Illegal connections

3. Household SuDS

4. Non-household SuDS

5. Highway schemes

Illustrations include:

• Rain gardens

• Highway SuDS

• Tree pits

• Natural drainage features

• Newport High Street proposals.

---

Slide 14 – High Street Fareham CSO

High Street Fareham CSO

The overflow releases into:

• River Wallington

• Portsmouth Harbour

Sensitive designations include:

• Designated shellfish waters

• RAMSAR

• SPA

• SSSI

• Bathing waters

Recorded spills in 2023: 92

---

Slide 15 – What Was Causing It to Spill?

What Was Causing It to Spill?

The investigation identified two principal causes:

• Extensive impermeable area.

• Connectivity of surface water into the foul sewer.

The slide includes maps illustrating both catchment impermeability and sewer connectivity together with rainfall thresholds for spill probability.

---

Slide 16 – How We Disconnect

How We Disconnect

Example:

• Soakaways

• Lysees Car Park

• Approximately 3,500 m² disconnected.

---

Slide 17 – Further Disconnection

How We Disconnect

Further examples include:

• Large warehouse separation.

• Approximately 2,100 m² disconnected.

• More than 50 domestic properties disconnected.

---

Slide 18

Primarily a photographic slide illustrating completed drainage separation and SuDS works.

---

Slide 19 – High Street Fareham CSO Results

Results

Outcomes achieved:

• Over 1 hectare of impermeable area removed.

• 12 spills during 2025.

• Successfully survived a 15 mm rainfall event.

• Next step is scaling up the approach.

Includes performance tracking graph for 2025.

---

Slide 20 – What Next?

What Next?

Typical separation costs:

Intervention	Cost
Domestic	£150–250/m²
Soakaway	£100/m²
Non-domestic	£50/m²
SuDS	£300–500/m²

Progress to date:

• Approximately 120 properties disconnected from around 800.

• System successfully survived a 27 mm rainfall event.

Slide 21

The slide is almost entirely graphical and contains no significant extractable text. It appears to continue the theme of practical examples of storm overflow reduction measures.

---

Slide 22 – How Can I Help?

How Can I Help?

Everyone can help reduce storm overflows by:

• Use permeable paving for paths.

• Depave your driveway.

• When building an extension, ensure your surface water is correctly connected.

• Collect rainwater or slow it down using slow-drain water butts or rain-garden planters.

• Speak up about green spaces in your community and take an interest in local planning matters.

• Only flush the 3 Ps:

  • Pee

  • Poo

  • Paper

• Report any pollution you see via the Southern Water website.

---

Slide 23 – Water Quality

Water Quality

A title slide introducing the subject of water quality.

---

Slide 24 – Other Activities

Other Activities

Additional strands of work include:

• Area-based charging.

• Stormwater management policy linked with local authorities.

• Schedule 3 implementation.

• Engagement with Local Plans.

• Lobbying.

---

Slide 25 – What's Next?

What's Next?

• Southern Water has almost 1,000 storm overflows across its region, and around half already meet the Government's new 2050 target.

• The Clean Rivers and Seas Plan proposes investing £1.5 billion between 2025 and 2035 to reduce storm overflows.

• The strategy prioritises green solutions together with optimisation of existing assets as a long-term approach.

• The first phase includes £700 million focused on environmentally sensitive locations such as shellfish waters and bathing waters.

---