That would have been exceptionally embarrassing if the electrical engineer didn't know how to turn that thing on. Thank you, Mayor. Thank you, Councillors, for the opportunity to brief the committee. My intent here this afternoon is just to give you a bit of an insight into, I suppose, the challenges and the work that we have underway and, I suppose, the effort that goes into managing electricity network across the Hawkesbury, particularly in flood-type events. So I sort of hope I meet the brief and answer any queries that you have at the moment. In terms of the context, so my role within Endeavour Energy, I'm the lead network resilience engineer. Relatively new role, been in this position for coming up to two years now, so just started in the middle of the last of the major floods in '22.
And so my focus is really to coordinate the effort across Endeavour Energy, looking at the resilience of our network for all natural hazards, bushfire, flood, storms, coastal inundation, heat wave, all the exciting stuff. We have put a fair bit of effort into resilience in our business, and recently we've just been through a process of, we have a five-yearly sort of regulatory reassessment and submission of our proposed program of works, and that's approved by the Australian Energy Regulator. After a couple of years of effort to get that together, that was approved just very recently, and network resilience was a key aspect of that, and certainly a key aspect of the feedback that we had from our communities, something that they wanted us to focus on as an organisation.
For those who don't appreciate the scale of Endeavour Energy as well, we cover 25,000 square kilometres from basically near enough to Batemans Bay, right through the Shoalhaven, Illawarra, up through the Southern Highlands, Western Sydney, up to you folks, up through the mountains, up into the Midwest, almost as far as Mudgee. So we've sort of got a very diverse and very large area that we cover while we're sort of looking after everybody else as well as the needs of this particular community. In terms of resilience, just to be sort of set the stage, I suppose, there's sort of four different aspects that we focus on. And I don't need to make this a lecture, but just to give me some focus and keep me on track, we've historically done a lot of work anticipating the impacts of natural hazards on our networks.
So we have a bunch of plans that we activate triggered by various flood levels along the Hawkesbury. We will design our network to withstand events as much as we possibly can, but of course we can't, you know, stay standing all the time. So part of that then is the recovery aspect and really throwing the resources and effort into recovering and improving our recovery over time. Unfortunately, like everyone else in this room, we're getting very, very good at responding to floods on the Hawkesbury, I think. We've learned a lot over the last few years. And finally, the important part, of course, then is feeding that back through and learning the lessons that we've had from previous events, seeing how we can do things better, whether it's in my space and actually looking at the network hardware and the arrangement of the network, or just some of the softer factors around how we respond to emergencies and manage those sorts of events.
So really the context for us from the sort of events back in the major flooding events in 2021 and 2022. Be well aware we've had sort of in the order of 900 buildings sort of destroyed or damaged across our franchise area, and the bulk of that was up here. We had some pretty major customer disruptions. We did have a peak where we lost sort of 20-odd thousand customers because of water impact or imminent water impact on some of our key transmission lines feeding the area. And we had in the order of sort of 600 customers off for multiple days. It sort of took for the water to come down and for us to be able to restore network supply in particular areas. We sort of mustered a team of over 70 staff to feed and work through this area, and it took us sort of five days to actually work through and get that main sort of network restoration complete to the point where it was just sort of individual properties and things that we needed to get back connected again.
And for Endeavour Energy, just to give you some context for us, it was a cost in the order of a million dollars for each of these sort of major flood events in terms of the network damage, our personnel costs and equipment costs to actually respond to these events. So not an insignificant effort for our folks. When it comes to restoration, I suppose, yeah, the restoration of customers, Endeavour Energy, our remit , if you like, is really very strictly the network. Basically, the first point of connection into a property, it becomes officially under New South Wales law, it becomes the consumer's electrical installation, and there's a demarcation there between what we're allowed to do as a network provider and then what becomes the domain of basically, effectively the homeowner or the premises owner as the owner of their own...
Property , including the electrical installation, and they need licensed electricians to conduct inspections and do work on any repairs that are required for that. So that's why you'll see when we go through a response to a flood event, our primary goal is restoring the backbone of the network. Part of that will be to disconnect all the properties that we know or suspect may have been inundated during the course of the event, because we certainly don't want to cause any safety issues for residents in houses that may be unsafe, may have electrical faults internally that haven't been identified or made safe yet. And so for the safety of the community, we'll just basically restore to the street out the front of the property until we get the all clear that a property is safe to re-energise.
So that's sort of the approach that we take, sort of house to house. In terms of the arrangement of the network in this neck of the woods, I know that's a very busy picture and probably doesn't make a lot of sense. You won't be questioned on this later. But fundamentally, the challenge for us is where the Hawkesbury sits, all of the key supplies through the Hawkesbury come essentially from the south. So we're on the fringe of our network area here and in a little pocket. We talk about transmission and distribution in our network. So the transmission is like the backbone of our network, and that's the colours on the map that you see on the screen at the moment. So we have a number of transmission feeders that supply large substations, and then the distribution network then takes that electricity out to individual street houses, premises throughout the area.
So as I say, the challenge for us is all of that transmission supply into the area actually comes from the south. Anything that goes to the west of the river has basically, because of the geography of the area, must either get across floodplain or make multiple river crossings to actually get to where people live and reside on the other side of the river. So there's some physical challenges in actually getting our network into those places. There's some physical constraints on actually how high we can make things. Obviously, there's an obvious thing, make poles higher and that sort of thing to try and get the wires out of the water. But then we end up in a situation where we physically can't reach them to repair them and do the things that we need to do.
So there's a balancing act there to make an efficient, effective network that works 99.9% of the time and trying to find those little sweet spots and little things that we can do to improve those under those flood sort of events. So I hope that makes sense in terms of the arrangements for us. Really, the key challenge for us is with Blue Mountains National Park, Wollemi National Park, all around us, there's no easy way and there's no sort of population centres on the other side of the river that we can easily bring other supply into the area from. We're pretty well constrained with that feed-in from the south with the way our network and other networks around us are built. I suppose in that, for a bit of context for the committee, our modelling indicates that basically up to a 1 in 100 flood level, we should be able to maintain supply into the district.
But if we exceed that 1 in 100 flood level, so normally 17.3, 17.5 metres, then the entire electricity supply into the Hawkesbury is at risk because of... The water levels in relation to incoming transmission lines and other transmission assets. I'd imagine that's pretty well the point where UFACs are trying to pretty well evacuate most of the area, so I'm not sure anyone's going to be here to be too concerned if there's power or not. And I'm sorry, I don't mean that facetiously, but that's part of the challenge for us in sort of weighing up further investment, you know, whether there's value in actually trying to harden the network past that point for a one-in-a-hundred event that we haven't seen since 1867.
So that's part of that sort of decision-making for us. Because everything that we do, everything we invest in in the network, ultimately our customers need to pay for, and so it's trying to find that balancing act of having an efficient, cost-effective network that does the job for most people most of the time. So off the back of the last few floods, we've spent quite a bit of time sort of analysing the impacts on our network and trying to get our heads around the sort of the topography and where our weak points are. So we've looked at a number of specific sort of situations around replacement of individual poles where we might be able to sneak a taller pole in to clear a particular low point, replacement of entire sections if it's warranted to sort of get higher above the floodplain where we know we continually get hit and it sort of makes some sense for us to try and get a bit higher.
Even little things we've found, like just some basic engineering things around just sort of tightening things up and a few little quirks we can potentially get some benefit from. But also one of our challenges in a flood response is the switching of the network to make safe as an event progresses. So we've got pre-prepared plans , switching plans, where we'll operate. I will start to isolate sections of the network depending on water levels, so three to four metres, four to six metres, six to eight. There's key triggers as we all watch the gauge at Windsor Bridge. And so as the event progresses, we're trying to get in and isolate the network before it becomes damaged from water or poses a risk to the public because of access issues and that sort of thing.
One other key challenge for us in that switching plan is we will, sometimes we will need to switch off sections of the network simply because we know it's about to become inaccessible . So while people may still be high and dry and may still think that everything's okay and they don't understand why they have no power, it's because sort of the next step is a critical road being cut off, a line potentially going underwater and us not being able to get there to make things safe and respond to that. So that's all part of that balancing act as well. So that's the sort of work that we've been doing at a quite a detail level. Like I say, we have been through this recent regulatory approval. We did put forward, I suppose, a fairly modest investment package focused around flood resilience in the Hawkesbury.
And it's really the first time that the Australian Energy Regulator has considered resilience-type investment, proactive investment for electricity networks. There's sort of a history where the , I suppose, the conventional wisdom is some people think it's cheaper just to let everything wash away and then rebuild it as quick as you can, and that sort of seemed to be the most economic solution to the problem. But we were able to convince the AER that we've actually got some methodology here that makes some sense. We've got now some detailed design and assessment work underway for a whole bunch of projects in this area. Up on the screen there, some work that we had already completed after the 2020 flood—sorry, 2022 flood.
So we reconfigured the transmission crossing at Windsor Bridge, I think in about September '22, and so that's given us an extra two to three metres of clearance over the river there. That crossing in particular, we had to switch off for the safety of the public and SES boats and people moving through the area in the events in '21, '22. So that was one that we sort of knew was a weak point for us, and we wanted to try and get some extra clearance there. So we were able to do that pretty quickly at the time. So just that one link probably caused the proactive isolation and blacking out, if you like, in the order of sort of 4,000 customers up to Cattai and Wisemans. So people that are well and truly high and dry but weren't able to get the transmission supply to them because of this particular area.
So we'll do a better job of keeping those customers on next time, when there is a next time. Also, down the bottom left of the screen, pretty Teco-looking drawings, if you're into that sort of thing, but that's some design work we did on a particular weak point again, a single sort of span that we knew was a problem that actually interrupted feed into Pitt Town. And so we actually rebuilt that line. Again, not too far after September '22, actually. So a couple of key points, and again, that blacked out in the order of 1,000 people just because of that one crossing. So we've made those adjustments, so we're better prepared, better able to deal with future major flood events. And just, I suppose, to close out the last sort of before and after photos I've taken of the rebuild of that transmission feeder at the bridge.
Everyone will probably recognise the bridge pretty well there. The photos don't really do it justice, but as I said, we're just a really simple sort of reconfiguration of the way we've constructed those lines meant we could actually get an extra two to three metres of clearance and hopefully , yeah, keep us out of the water right through to a major event or past a major event next time it comes up. Apart from this sort of work and the other work that we're doing, worth noting too that we have had some feedback through inquiries and certainly feedback from the communities around the importance of communications across the area. And we need it as much as anyone because we need to talk to our people to tell them where to go to fix things.
And so we are working pretty closely with all the telco providers at the moment to better understand where their assets are, where they sit on our network, where we can do some things to work with them, give them a better sense of how quickly we can respond to things and see if we can find some ways to help them stay up in future. So there's a bit of work sort of happening in the background with that as well that's worth the committee noting. I'll stop talking there because I've probably gone for way too long.