Belfast Telegraph

David Porter: 'We plan a lot on the dry days so we are ready for the wet ones'

Linda Stewart talks to David Porter, chief executive of the Rivers Agency, about the challenges in dealing with the deluge of rain that has hit Northern Ireland in recent months.

Q. Could you tell me about your background?

A. I'm chief executive of Rivers Agency. Rivers Agency is the statutory drainage authority for Northern Ireland. I've been chief executive since April last year and I was director of Rivers Agency for five years before that. I was the regional engineer for nearly five years before that, so my whole career period within RA has been just under 10 years. Before that I was in Roads Service for 10 years.

Q. What are the biggest flooding hotspots?

A. It depends how you define hotspots, and also what sources you consider. So the way that we communicate flood risk to people is using the strategic flood map. On the strategic flood map you'll see information risk on the risk of flow from rivers and from the sea. We also have our surface water flood map, and that's flooding which is a consequence of very intense rainfall. Because of the EU Flood Directive we've also done a significant amount of analysis to see where the economic impacts are going to be and what we have identified are 20 significant flood risk areas. Of the 20, Belfast is right up at the top of that, not just because of the flood risk and risks associated with that but because of the amount of economic activity, the properties and the people, and the services that are delivered.

Q. What do you do when you learn that very bad weather is on the way?

A. We do a lot of planning on what we call the dry days so that we are ready for wet days. We normally get an early weather warning a number of days before the storm and that kicks off the process of checking our infrastructure and checking our grilles. A grille is when an open watercourse goes under the ground through a pipe or a culverting system, and the interface between the open section and the pipe section is where they want to collect any debris. So they put bars across the opening of that pipe and catch material in an area where it is possible to remove it.

So whenever we get weather warnings the industrial squads go out and do a grille run to make sure certain grilles are quite clear. They normally do that routinely, on a weekly or monthly basis, but they also do it when they get Met Office warnings. They also do an assessment of just how a bigger event will actually affect the level of the rivers, what the weather has been like in the few days leading up to it. Then all those factors dictate what our reaction is. So, for instance, we recently had very wet ground and high rivers, so any weather warning generally requires us to have people on call. If we're going to see very large amounts of rain, then the night before when the guys go home, they would actually put their sandbags on their vehicle or in some cases take one of the pumps and take that home with them, so that they're ready to respond overnight rather than having to come back into the yard and pick one of the pumps up. But we only do that where we are genuinely concerned because of the amount of rainfall, and it depends on what the weather warning tells us. So there's been a lot of emphasis on that information from the Met Office and it helps us then make an assessment of the kind of input there is going to be.

Q. What are the biggest dilemmas you faced in the recent flooding - is it a balancing act?

A. We've had wave after wave of winter storms and we've been in a state of very high alert from late November and December. It's been constant throughout that. So far our biggest challenge that we've faced at that time is making sure we allocate the resources that we have to best effect, but at the same time not overtiring particular resources, so there's been a lot of focus in and around our Armagh office. We've actually had to move squads from some of the other areas where there's less impact in order to allow men to go and rest, so that we can continue to man the pumps and provide that service.

I would like to pay tribute to the staff. There are many examples of individuals going the extra mile during the recent flood event. A lot of the work fell over the holiday period over Christmas and New Year and a lot of staff gave up their leave to come in. They would have been pumping throughout the night.

I have been out visiting our staff on cold, wet, windy nights and they've been very focused on helping communities and very focused on keeping the pumps running.

Q. Could anything have been done differently?

A. There will be a review, and with the benefit of hindsight we could identify some things which we would do differently. Certainly my response has been that everything that could have possibly been done as far as I'm concerned has been done, in terms of preparation beforehand, advising and providing information to other organisations, down to co-operation with other agencies throughout the event. Also in terms of managing the loughs - the Toome gates were open fully since early November - and also in terms of effort from staff who have been pumping at a number of locations 24 hours a day for weeks. Their efforts have been very significant.

Q. Are you noticing any difference in the incidence of significant events over the last few years?

A. In the last number of years we seem to have had more very significant rainfall events. But a couple of things have happened to bring flooding clearly to people's attention. One is 24 hour news, so people would be more conscious of flooding. When you compare floods nowadays with floods that happened 50-100 years ago, the significant difference is what is in people's houses to get damaged. We're a much more affluent society than we were 100 years ago so the pain and the loss associated with flooding can be worse. You can't use such a short period as the last 10 years to say the climate is actually changing. But something is happening out there - we're starting to see the shape of a pattern and hopefully a few more years will confirm whether El Nino is back, or is it just what nature's throwing at us or whether this pattern of weather is going to become the norm. Certainly, if this is the norm going forward, we need to think differently about flood risk management.

Q. If this keeps on, what is it going to be like in Northern Ireland in 50 years' time?

A. As I said to the Stormont agriculture and rural development committee, if this is the pattern now with the predictions of climate change, we need to recognise that we may well be fighting a losing battle. If the climate changes quicker than we can put in schemes, then we need to actually recognise that and work with that. That's not just saying we'll just leave places to flood and just give up. But you have to take a certain different view of it, you need central government and local government and communities and individuals to work together to understand the risk they face and to be ready for floods to occur and to keep a watch. We need to recognise that there isn't necessarily an affordable technically possible scheme to stop flooding. And people might have to make some changes to protect their property, physical changes to minimise the impact of flooding. Recently the minister has launched the home owner flood protection scheme and that's really in recognition of that. In certain areas where there are clusters of properties, you can write a business case that says 'Yes, that is viable, it is possible for the Government to step in and construct something that will minimise the impact'. But that's not always possible, and rather then just say sorry, we can't help, we developed this scheme that is designed to give them assistance if they want to make physical changes to their properties to minimise the impact of flooding.

Q. Is it better to speed up the flow of water or slow it down?

A. It depends where you are within a system. If we have a flooding problem in Coleraine, where there's a relatively short distance between Coleraine and the sea, it would be a good idea to get the water from Coleraine into the Bann and out to sea as quickly as possible. If you're in a different type of situation in a different area and you're dealing with a different type of flooding, by straightening or making the water move more quickly you could cause a problem to the next town downstream and in that case you would take a different approach, either flood storage or reconnecting rivers with flood plains, using a natural flood risk management approach.

Q. Are you looking at ways of increasing the water holding capacity of uplands?

A. Basically, with flood risk management plans that's one of the areas that we're looking at. It's no longer about focusing just on the problem area, but we do take a catchment-wide approach and that will include land management in the uplands. Secondly, while there is still a case for some hard engineered schemes, similar to those that we saw in the past, in some areas it may be possible to reconnect rivers with flood plains by the removal of flood banks. This will not be appropriate in all areas, as there may be property that would be at increased flood risk if the defences were removed, but making space for floodwater rather than constraining the river system is a better long term approach, particularly given the climate change predictions. Flood plains are protected through our planning process by not allowing inappropriate development to be permitted. We take this approach because it is better to avoid the risk of property damage rather than allowing development and then constructing defences to reduce the impact of flooding. Within the planning system there is a clear presumption against development in flood plains, except for a small number of exemptions.

Q. Would you consider compensating farmers to allow rivers to flood their land?

A. It's certainly something that the industry has been thinking about for some time. It's a difficult one from the point of view that the flooding was there for a long time before the land was even farmed. I think the real issue is that some areas have benefited from defences which are no longer viable in the future.

Q. Are you disappointed that this approach wasn't included in the latest agri-environment scheme?

A. Not so much disappointed, because I'm not sure we're actually at a point where there is a set answer to that, or an acceptance of that. I think where I would be disappointed is that if the industry had got to a point where everyone was in agreement that this was a good idea and it didn't make it in, but I'm not sure the answer is just as clear cut as that.

Q. A number of road schemes are proposed that would go through flood plains. Are there any special measures that would need to be taken so this wouldn't cause problems?

A. Under our planning policy, PPS15, there is a general presumption against development on flood plains. The exception to that is when it's regionally significant infrastructure and there is no option other than to put it there. As part of that under PPS15 they need to demonstrate that they have mitigation measures that they will put in to compensate for the loss of flood storage. They need to demonstrate that by building that road in the flood plain that they are not actually increasing the flood risk elsewhere. So part of the design of that road will be the risk assessment to assess water levels beforehand. They will model the new road scheme to determine the difference in water levels and see what it impacts upon and make sure there is no harm to property or essential services or anything else.

Q. Is there a role for dredging - could it have helped?

A. It could possibly help in certain circumstances, so where you get lower flows or they're trying to support land drainage, it could help, particularly in a rainfall event where the water stays within the river channel. If half of that river channel is compromised because of silt, that will have an impact on the land drainage. Whenever we start to go up into bigger flood events like the recent one, the river channel plays a smaller and smaller part. Whenever the river exceeds that river channel and spills out across the flood plain, it's actually that whole flood plain that is carrying moving water. If you compare the size of that whole flood plain with the small channel, the channel plays less and less of a role. But we have good standards of watercourse management across Northern Ireland. Rural watercourses are inspected and maintained on a six-year cycle and urban watercourses are inspected and maintained on an annual cycle. So we do have a good level of watercourse maintenance and we've a very good legacy of that.

Q. The scheme in Orangefield Park used the park as flood storage and to divert water away from houses. Are you hoping to use that approach again?

A. Orangefield Park was a capital scheme. The local community wanted to redevelop the park and were able to draw down money to improve local facilities. The project took a different view of flood risk management, and we were able to relocate the river within the park, move it further from the houses and reshape the ground to give the river more space. In a flood event the river would have been constrained, but now it can quite happily spill out across that park. The river goes up and down quite quickly and it doesn't really cause any lasting harm. We have photographs of the recent event showing some very high floodwater. In the absence of that scheme, that water would have been in people's houses. With a lot of places it's difficult to use this approach because the decisions of the past have put properties close to rivers. In this case you have a river going through a park which you are able to reshape without actually having to knock down homes.

Q. Is there anything that the rest of us should be doing that would make your job easier?

A. There's a number of things. First of all, we encourage people to look at flood maps for an understanding of the risk that they face. On June 12 we saw some very high intense rainfall over urban areas. If homeowners can keep their own drains clear, that gives more resilience to the situation and we would also ask them to be conscious of whether there are rivers and grilles and culverted systems on their property. If there is a grille and the homeowner sees a build-up of material on it, it would be useful if people could report it to the flooding incident line before something happens. When we get a Met Office warning we go out and check on our grilles, but you can't be everywhere at all those grilles - there are 1,000 across Northern Ireland.

Q. Is there anything we can do so that farmers don't have to face having part of their land in Lough Neagh every year?

A. What we faced through the winter storms was a significant amount of rainfall so we did see very high levels in Lough Neagh, higher than we've had on recent records. We don't normally see water levels of this height and wouldn't expect to see them routinely. Firstly, I would encourage farmers to view the information on Flood Maps (NI) to understand the risk they face and take this into account when planning their business activities. Secondly, the management of the lough levels is part of the ongoing review and this will provide further useful information on the limitations of the management regime as we need to understand that it is not possible to stop all flooding. The recently launched homeowner protection scheme is a pilot scheme to widen our approach to the management of flood risk. Details are available on the NI Direct website.

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