Official Report: Minutes of Evidence

The Chairperson (Mr Martin): We have Martyn Harvie, vice chairperson of the Institution of Civil Engineers (ICE) Northern Ireland. Martyn, you are very welcome; thank you for coming in. You will make an initial presentation, and you can then expect some questions from Committee members. We also have Adrien Baudrimont, senior research manager at the Construction Industry Research and Information Association (CIRIA), who has popped up on our screens remotely. Adrien, you are very welcome as well. Martyn, we are in your hands.

Mr Martyn Harvie (Institution of Civil Engineers): Thank you. Adrien and I had a conversation yesterday to try to manage some of the coordination and timings of our contributions. Hopefully, that will help us a bit this morning. I have a statement, and I will read some of that out. Then, if it suits the Committee, we can take it from there.

I thank the Chair and Committee for giving ICE the opportunity to provide evidence on the Water, Sustainable Drainage and Flood Management Bill. I am representing the Institution of Civil Engineers as the body's vice chair for the region. I am a chartered civil engineer for AtkinsRéalis in Belfast, and I have worked in the field of urban drainage for over 25 years. Throughout that time, I have worked with NI Water, DFI Rivers and the Department, including with Simon Richardson and his team there.

For anyone who does not know, the Institution of Civil Engineers is a 95,000-strong organisation with a global membership and nearly 200 years of history. Its mission is to improve lives by ensuring that the world has the engineering capacity and infrastructure systems that it needs to enable our planet and those who live on it to thrive. It is a centre of engineering excellence, qualifying engineers and helping them to maintain lifelong competence, assuring society that the infrastructure that they create is safe, dependable and well-designed. ICE's network of experts offers trusted, impartial advice to politicians and decision makers on how to build and adapt infrastructure to create a more sustainable world. I will do a brief introduction, if that is OK, and then hand over to Adrien.

As I said, ICE operates independently from government engagement, maintaining its status as a professional body. ICE considers the integration of nature-based solutions or sustainable drainage systems (SuDS) essential in all new housing developments. SuDS not only provide effective water management both in water quantity and water quality but deliver wider social, environmental and amenity benefits. At a time when accessing green space is increasingly limited and modern housing schemes provide fewer communal areas, the inclusion of SuDS is necessary to support public health, well-being and community resilience. It is recognised that surface water management, including SuDS, can play a part in reducing flood risk, which is topical, following yesterday's events; increasing resilience to climate change; and reducing pollution such as combined sewer overflows (CSO) spills, as well as surface water run-off to watercourses. SuDS can also help to create headroom in existing sewer networks to facilitate the new connections from new developments.

SuDS are not new across these islands. The types of SuDS can be varied, and there are many examples of SuDS projects that have operated successfully, in some cases for many decades. I am happy to share examples of those after the meeting, if that helps. The Committee may be aware of local examples of SuDS in practice in private developments, some retrofit projects and DFI Roads projects. Whilst they are not commonplace here, they are not new either. Their design and maintenance have been the subject of much research, and Adrien may talk about that. There is a good standard of industry best practice on technical elements, including principally from CIRIA. However, those benefits can be realised only in the context of a clear and robust regulatory and policy framework, including a sustainable funding model. ICE welcomes the fact that the Bill provides that clarity.

I will hand over to Adrien to make his opening statement.

Mr Adrien Baudrimont (Construction Industry Research and Information Association): I am a senior research manager at CIRIA — Construction Industry Research and Information Association — which is a member-based organisation that provides independent good practice guidance on surface water management, among other things. We are known for our guidance documents. The one that is relevant to our conversation today is the 'SuDS Manual', the last iteration of which was published in 2016. That is widely known in the industry and is a point of reference for many standards and regulations across nations. We have published other guides on that topic. Last year, we published guidance on enabling community maintenance of flood-risk management assets, including SuDS. We also published a guide for land agents on how to secure the benefits of SuDS from the early stages of a project directly from land acquisition.

CIRIA has several communities of practice, representing practitioners on specific topics. Today, I will represent not only CIRIA but Susdrain, which is the community for sustainable drainage. That is a vibrant community with a strong membership that includes regulation agencies, practitioners, designers, water companies etc. That group has been critical in providing advice, comments and feedback on SuDS policies, standards and practice throughout the UK. CIRIA highlights best practice through our yearly awards cycle. We award the best in design, implementation and maintenance of multi-benefit SuDS. Every year, we try to put forward the best projects and the champions that make SuDS happen.

As you know, a lot has been going on lately. In Wales, there have been learnings from the schedule 3 implementation in 2019. There have also been changes to planning policies in England, including the release of new national standards in England last year. There is a lot that is happening UK-wide in the field.

It is great to have been invited to provide oral evidence on the Bill, which is a step in the right direction. I want to highlight that, from our standpoint, Northern Ireland has several advantages, one being a slightly less complicated landscape that does not have the layer of private water companies that there is in England. Northern Ireland is leading on the right to connect not being automatic, which is a great advantage. We recognise that there are some things that work and some that do not, on which there could be learning from other nations. We will probably put some of those forward during our conversation today.

Before we start with questions on the evidence, I point out that I am not a drainage engineer or a policy specialist. If there are questions that I cannot answer, I will get back to you on them after consulting Susdrain and the professionals. Lastly, the overarching goal of Susdrain and CIRIA is to promote, support and sustain high-quality, multi-beneficial SuDS for people and nature.

The Chairperson (Mr Martin): Thank you, Adrien and Martyn, for giving us some evidence on the Bill. I will start off with a question that Adrien might take, but, Martyn, if you are feeling enthusiastic, you can take it.

Adrien, you mentioned key learning from other areas of the United Kingdom, and you mentioned England and Wales. Will you tell us more about what that key learning might be? As the Bill progresses, how can we learn from other regions to make it the best that it can be?

Mr Baudrimont: Most of the comments that Martyn and I will share today will touch on that issue to some extent. There are so many things that have been going on in the rest of the nations that could be taken on and serve as an inspiration for strengthening or reframing aspects of the Bill.

I will start with one key aspect that Martyn will probably want to jump in on: the notion of statutory versus guidance. That is about understanding that the Bill is, of course, about creating primary legislation, with detailed regulations to be defined at a later stage. It would be beneficial if the notion of statutory or guidance — or statutory guidance: who knows? — was clearly stated in such a Bill. For example, in Wales, there is no grey area; it is all mandatory. There is clear guidance for how that applies and what developers should consider. There is a bit more of a grey area in England, with the statutory definition not being as clear as it is in Wales. That has led to a disparity in respect of the SuDS that are being implemented. It would be key to clarify that, if possible.

Martyn, do you want to touch on that?

Mr M Harvie: There are a couple of minor things. On key learning, the technical guidance and best practice on the engineering aspects of SuDS are relatively well developed, pretty comprehensive and sufficient for practitioners. A lot of that work is being done by CIRIA, and, as Adrien said, the issue is more around the way in which we bring the statutory requirement for the measures into local legislation. Ultimately, adoption and maintenance is probably the main area in which the Bill is required to be clear on where responsibility lies. It also needs to be clear on sustainable funding for whichever government body owns that responsibility.

The Chairperson (Mr Martin): That is useful, Adrien. You have probably covered my second question, but I think that you said — correct me if I am wrong — that there is clarity in the primary legislation in Wales. That primary legislation contains clear definitions and policy outcomes that it wants to achieve. Those were not left to subordinate or secondary legislation; they are in the Bill. Is that what you are saying about the Welsh model? I want to tease that out.

Mr Baudrimont: Yes, I think that is it. It provides a little more clarity about what can be expected. To have it stated from the get-go in a Bill would facilitate later implementation. For example, after the passing of the Flood and Water Management Act 2010, it took Wales nine years to implement schedule 3, which has mandatory complements with regard to SuDS. Sixteen years later, England is still not there. Clear milestones and time frames for the implementation, with clear statutory duties and standards, will help greatly in making sure that the provisions are delivered in a timely manner.

The Chairperson (Mr Martin): This is great. Your answers on this topic are really useful, so I will stay with it for a second — at this rate, I will probably never get to my fourth question. Given what you just said about the English and Welsh model, is the fear that the provisions in the subordinate legislation will take a while to happen if the duties are not in the Bill? There are things that need to be brought through, but activating the subordinate legislation has taken a while in other jurisdictions. Is that what has happened?

Mr Baudrimont: Correct.

The Chairperson (Mr Martin): That is fine. I have one more question before I hand over to the Deputy Chair, John. This is not a particularly technical question, but is clause 2 sufficient? Does it require any change? Are there any unintended consequences that may occur as a result of the way in which it is drafted?

Mr Baudrimont: Do you want to start, Martyn, or shall I jump in?

Mr M Harvie: No, carry on. I will focus on the questions about clauses 4 and 5. If there is something specific on clause 2, I can leave it to others or pick up on it afterwards.

Mr Baudrimont: That is fine, thank you. Correct me if I am wrong, but in clause 2 there could be clarity about the identity of the approval bodies. Where will the responsibility lie? Will it sit with the local authorities, Northern Ireland Water, DFI Rivers or other organisations? What will be the direction of travel for the roles of the approval bodies?

The Chairperson (Mr Martin): OK. That is fine. Other witnesses who gave evidence to the Committee suggested that the responsibility could lie with DFI Rivers. Nearly every group of witnesses has suggested that it needs to be defined. We have heard that repeatedly. Be assured that we will ask the Department, if it engages with us, to define that. If it does not, we will. Do not worry too much about that one, because we will get to the bottom of it.

I might have one more question, but I have talked for long enough. I will hand over to the Deputy Chair.

Mr Stewart: Adrien and Martyn, it is great to see you. Thank you so much for your answers so far; they have been very useful.

Adrien mentioned that Northern Ireland is in a good position to develop the legislation, and the Chair touched on that subject. If you put yourself in the position of a scrutiny body and a Committee that can make amendments, what is your assessment of the Bill as drafted? If you could draft and add amendments so that the Bill could deliver further, what would they be? What would you like to see the Bill doing?

Mr M Harvie: That would need a written response to be honest [Laughter.]

Mr Stewart: I am not looking for you to draft them, but in which areas could the Bill have gone further? It is about how we might use the information that you give us today to help us draft amendments.

Mr M Harvie: I have some notes on where responsibility lies for adoption and maintenance and on the role of a SuDS approval body, although I do not want to assume an outcome on that. We have covered technical best practice, so I will pick up on the SuDS approval body piece. To echo Adrien's point, it does not necessarily matter which Department the approval body sits in as long as its role and the way in which it operates are clear. You have touched on its having explicit roles and responsibilities. A lot more thought and detail are needed on the funding and maintenance of any new SuDS features, be they in a wider public space or in a new housing development. It would not be for ICE to suggest or recommend where the approval body should sit — that is for the Committee to decide — but I will be happy to provide wider comment on some aspects of the Bill after the meeting rather than speculate now. I have some general notes that I can jump in and out of.

Mr Stewart: We are happy to engage with you and take some of those points.

One thing that we hear from the sector is that, until now, there has been an inconsistent approach from the 11 council planning authorities. I am curious about the other areas that you have mentioned. Whether it be in England, Scotland, Wales or the Republic of Ireland, how important is consistency when it comes to applying such things through planning?

Mr M Harvie: I will use "SuDS approval body" as a generic term for whatever body forms here. There might be a view that it will create an administrative process in planning, but there is already a lot of administrative process in planning, and a number of statutory consultees have to form part of the planning process. Whether or not the approval body were to sit independently in DFI/DFI Rivers, it could be one more statutory or non-statutory consultee, depending on, as Adrien mentioned, how the Bill is drafted. That would certainly allow for greater consistency.

As I mentioned, the technical best practice part of it — the engineering part — is relatively straightforward. It is really about consistency in adoption and maintenance. Having one central place locally would allow for a more streamlined approach to how all that is done. The SuDS approval body could be brought in pre planning to advise and to ensure consistency of design, adoption and maintenance regime as part of the planning process. The body could advise at the front-end stage of construction design. Post construction, the SuDS approval body would need powers to check the maintenance regime and that the building had been done to standard. As in planning for things such as housing, such a body would need to be able to follow up in that way.

Mr Stewart: OK. That is useful.

As you will be aware, gentlemen, the SuDS features in new developments do not count towards the 10% open space requirement, often making them impractical logistically and financially. What are your thoughts on that? Should such features be included in the open space criteria to make them more financially and logistically viable?

Mr M Harvie: Maybe Adrien will come in on this. I would say that it might depend on the type of SuDS and whether and how it contributes to open space as part of the overall landscape. The general recommendation would certainly be that anything that improves the economic and social benefit to the community in which it is placed should get some credit. The direction of travel should probably be that a SuDS feature should be considered part of the open space, provided that it is the right type of feature. You will be aware that there is a range starting from simple straight-line, linear swales for which that recommendation might be a little more difficult to justify, but, for features in more open, larger areas, it would feel a lot more comfortable to lean into that objective.

Mr Stewart: OK. Adrien, have you any thoughts on that?

Mr Baudrimont: Yes. Nature-based SuDS would probably fit within that landscape really well. They can be designed to provide amenity for the people who live there, so they would not take up too much of the 10%.

There is the notion of engineered versus nature-based solution SuDS and the definition in the Bill of structural SuDS. I would like to learn a little more about the reasoning behind the definition, to set aside the structural solutions versus the nature-based ones, and about the adoption and maintenance requirements of those types of SuDS.

Maybe it is a question that is open to you, actually.

Mr Stewart: I probably will not be able to answer that.

The Chairperson (Mr Martin): Go on. Have a go, John.

Mr Stewart: I am not sure that I trust my engineering understanding of the matter, but I am sure that we will be able to find someone who can.

I really appreciate that. That is really useful, and we will look forward, Martyn, to getting responses back on some of those points from you via the Clerk.

Mr McMurray: Thank you, Adrien and Martyn, for coming along today. I will keep pulling the wee thread about the regulation bodies, the approval bodies and the maintenance bodies. You mentioned that Northern Ireland has slightly different local government set-ups and regional government set-ups from other jurisdictions. What powers will those bodies need in order to perform? I am not necessarily asking you to say where it sits, because obviously it is for us to have an understanding. What powers will the approval body need, what powers will the regulatory body need and what powers will the maintenance body need, if that makes sense?

That is as much to Adrien. I know that Adrien is on the screen.

Mr M Harvie: It is good to break it down into those categories. Approval-wise, it is probably similar to what the likes of NI Water or DFI Rivers have in constructing infrastructure that would be subsequently — again, I will use the word — "adopted", depending on what form that takes. There needs to be a standard. Again, there are good technical standards on what the SuDS features need to look like and how they perform. The first thing around approval is that they are designed to an acceptable standard and the approval body can confirm that that standard is met. That is relatively straightforward, because there is technical best practice on how such things are done, and that can be checked, like any design of any infrastructure, such as a bridge, a road or a railway.

The regular maintenance of those is probably a bit more nuanced. There is increasing good practice across these islands in how that maintenance is done, and, again, that very much depends on the type of SuDS feature. Swales, ponds and trenches will all have slightly different needs in how often they are looked after. Obviously, proactive maintenance is preferable, but, again, being mindful of the economic situation that we are in, the key thing is that the body responsible for their maintenance has the powers to enter and undertake that maintenance, maybe similar to what the likes of NI Water or DFI Rivers do around clearing grilles or unblocking sewers. It is probably not more complicated philosophically, if you like, than that. Again, there are good examples of legislation that could be taken from across these islands on how it could be adapted for what we do here. Noting that the government set-up is different here, there are still bodies with responsibilities, regardless of what jurisdiction you are in. It is just a case of working out where that responsibility has to be placed around the government bodies.

The one thing that I will say is that we would have a concern if the maintenance of such features were left to private developer maintenance companies. Obviously, the longevity of those companies and the assurance of that best practice being applied could be a risk, especially if those SuDS features formed part of wider catchment management practices around flooding. Where they contribute to a catchment benefit, leaving the maintenance of those features to individual private bodies would pose a risk for the wider catchment. That responsibility for maintenance, if it is passed to a public authority, will need to be clearly outlined and, again, appropriately funded.

Mr Baudrimont: I support that. Provision for the funding and sustaining of the SuDS that are being put in place is key. It has been an issue in England particularly, where there is no strong regulation on the adoption and maintenance of SuDS, which could lead to some of the SuDS not being maintained and then, purely and simply, failing. Not only would they not be providing the water quantity benefits that they are supposed to provide for flood protection; they would not be providing the water quality, biodiversity and amenity benefits that they are supposed to be designed for. That is definitely a key point.

Skills and capacity are also key. It is important that you add something around training and bringing in professionals who have the expertise to review, approve, build and maintain the SuDS. To have the necessary funding for that is key. That was one of the key learnings from Wales after it implemented schedule 3 of the Flood and Water Management Act 2010 in 2019. One of the key barriers to success was the lack of skills and capacity in the sector, and the difficulty of retaining qualified staff in the approval bodies. Efforts to highlight that and to secure training and upskilling will be critical. That also goes for maintenance, of course.

Mr McMurray: Chair, you rightly mentioned clause 2, and Mr. Stewart mentioned the technicalities of it. You would like to respond to that at some stage — that would be great — but I am not going to press you on that now. Those things were certainly on my list of possible questions, so it would be good, but I will not question you on it now.

During your initial comments, Mr Harvie, I scribbled down some key points. Amenity spaces were on there — they are important. You talked about flood risk, which is a pertinent topic this morning, given that this is the morning after the day before. How much of an effect can SuDS have as a mitigation? Also, we understand how they will improve things in new builds, but where, what and how are the curtailments of retrofitting? It would be useful to understand how it affects that.

Mr M Harvie: Hydrological catchment is complex, and human interference in the hydrological catchment has sometimes exacerbated flooding situations. I am particularly conscious of the relevance of speaking about that today, considering yesterday's events, as you said. The whole purpose of SuDS is to mimic the natural hydrological cycle, so the more natural drainage features any catchment has, the more like the natural environment it will behave. That is not to say that we can make flooding go away, but it is about managing flood risk, as you said.

There has always been flooding. Rivers have floodplains for a reason: the weather that creates this sort of circumstance. How we interfere with that and how our infrastructure and where we live is impacted by and impacts on it can be addressed by SuDS. SuDS is one way of combating that. At their individual scale, SuDS bring what I would describe as incremental benefits to anything like that. It is about slowing down the speed of run-off, whatever it happens to be, within a catchment. The more we urbanise, the more hardstanding we have, the faster the run-off occurs and the more rapid the flooding in terms of peaks of flow. Individual SuDS schemes may not contribute specifically to significant benefits in catchment-wide flooding, but larger river management schemes that are more nature-based solutions to flood management certainly can. That is not to say that they do not bring benefits because, as I said, the incremental benefit piece is difficult to bring together when you are looking at individual housing developments.

When it comes to justifying the cost of SuDS, they can, in a capital sense, look more expensive than a more traditional solution. Adrien alluded to the skills challenge as well. Lots of contractors and government bodies know how to construct and maintain traditional grey infrastructure, as I describe it. Maybe constructing and maintaining this relatively new infrastructure poses an increasing challenge. Evaluating the benefits of that infrastructure, getting the funding and building the case to do what, we think, might be the right thing when it comes to green infrastructure and nature-based solutions can be more challenging when facing a green book business case appraisal, because the way in which we assess economic benefit can be quite fixed. It can bring benefits to overall catchments, but, if there are one or two housing developments in the middle of a flooded catchment, you are not going to say, "Yes, we can reduce it". Again, it should be a long-term return to a more nature-based way of dealing with rainfall and handling and managing water in our environment.

Mr McMurray: Thank you. This is my last question, Chair; I am using my three.

You mentioned headroom in waste water. I am trying to work this out, because, in Northern Ireland, SuDS comes in the context of a wider waste water issue that the Department is trying to sort out. How much headroom does it give in waste water infrastructure? You mentioned incremental benefits, and I am a big believer in marginal gains, like David Brailsford in the cycling and all the rest of it. On a scale of one to five, with one meaning, "Incremental, marginal, but will not really touch the sides of it", and five meaning, "Yes, this is a game changer", where do SuDS fit in?

Mr M Harvie: If you are talking particularly about SuDS in new developments or retrofitting in our existing urban environment, it is probably ones and twos rather than fours and fives. Grander nature-based solutions around flooding and urban drainage can bring bigger benefits, but it is about getting bang for your buck when it comes to investing the money that is available in such things to provide the benefits that you can achieve. It also a case of, as I said, how we quantify those benefits if it is simply a return on investment through a typical green book business case. CIRIA has a good guide on quantifying the other benefits. The east Belfast greenway is an example of where you could make an argument that having more people out and about in the fresh air helps the NHS and reduces pollution, because people walk more rather than drive.

All the other benefits of having blue-green space in the community need to be considered as part of the overall picture. If we are trying to justify investing in blue-green infrastructure purely on a flood removal basis or a flood risk reduction basis or on creating that headroom, you are in that marginal gains space — ones and twos — rather than the wholescale catchment effects. There are bigger plans through the work that NI Water and Rivers Agency do that will be needed to get the more significant benefits.

Mr McMurray: Thank you very much.

Mr Baudrimont: You said it really well. Thank you, Martyn. It is really about the multi-benefit aspect of SuDS and what they can bring. Real monetary values can be attached to those benefits in addition to the water quantity aspect, not to forget the water quality, which is also a key component. Between those ones and twos that were mentioned, with any SuDS intervention, little as it is, if it is dispersed into a cityscape, for example, the more you have, the less surface water will end up in the sewerage pipes, which will reduce the risks of combined sewer overflows or costly water treatment systems. They definitely bring some solid advantages.

Mr M Harvie: There is a campaign across England as part of its asset management plan cycle or water investment cycle around what the water companies would describe as unwanted water, and surface water run-off is certainly something that holistically should not be in a pipe.

Mr H Harvey: Good to see you today. Nice to see a "Harvie" with an "ie". I am getting confused.

Mr M Harvie: The proper way. [Laughter.]

Mr H Harvey: Yes. During a recent visit to Belmont Hall in Antrim, we had discussions around health and safety arrangements — features such as attenuation ponds. How can safety be balanced with usability?

Mr M Harvie: That question comes up often, particularly regarding open water features in housing developments. There are lots of examples of where they have been constructed. Adrien can maybe talk to that better than me. Sensitive or not sensitive planting arrangements can be done to encourage or discourage people from going into areas where, we think, there is risk. I have seen SuDS features in many parts of these islands simply fenced off and built into the landscape.

There is a big education piece for the public in the integrating of SuDS into urban and community environments. A lot of road accidents happen, but we do not suggest that we fence off every road because cars drive on them. I appreciate that standing water is a new thing that would be introduced to an environment where it currently is not. However, there are lots of SuDS features that do not need standing water to make them effective. They can be designed and the safety risk mitigated in a way that is sensitive to wherever you want to install them.

Mr Baudrimont: A situation that we are trying to promote through the different guidance is that, if most of the surface water on a site is conveyed via pipes and everything ends up in a pond at the end of the development, downhill, then that pond will have to be deep to accommodate all that water coming through. A deep pond means standing water and deep edges, so all of a sudden safety becomes a critical consideration. We advocate the avoidance of all those underground systems and instead having smaller surface SuDS interventions throughout the site that capture most of the rainwater when it falls and do not need to move it further down the line. That means that, in the end, the amount of water that needs to be taken into account for attenuation is much smaller than if you pipe it out throughout. That means that the pond can still be there but will be much less deep, with less standing water. That can then be designed into an amenity feature that allows for, as Martyn described, vegetation for people to observe or to access whilst removing any sense of danger. A combination of smaller SuDS features dispersed throughout a site will allow for less deep ponds and remove some of the risks.

Mr H Harvey: Have there been examples of health and safety issues at SuDS sites elsewhere in the UK?

Mr M Harvie: I would need to check the records to be sure. I am sure that there have been and that mitigation measures were put in place. Do you have any case studies, Adrien?

Mr Baudrimont: No, same here. There is health and safety guidance in the SuDS manual that basically takes into account the type of feature. There are health and safety assessments that can be done, and, following a checklist, measures to mitigate the risks. That is probably a good place to start.

Mr H Harvey: I appreciate that. As Andrew said, if it can be part of the 10% of open space, it is a good thing. I appreciate your answers. Thank you.

Mr Dunne: A lot of the points have been covered. Apologies for having to nip out earlier. I may have missed the maintenance of SuDS, so I am keen, Martyn, to hear your experience of that. I think you felt it best not to have private companies managing them. What concerns me is that they could leave a bit of a vacuum where they are built. They may look great at the time but not in five,10 or 15-plus years down the line. All those things need some level of maintenance. I am concerned about that. So many bodies — councils, NI Water, the Department and so on — tell us daily that they do not have the resources to do what they are doing at the minute. That is of concern for me. Do you have any experience of that or any best practice?

Mr M Harvie: It comes back to some of the design aspects, such as where the SuDS will be located and the sort of maintenance that there will be. There are examples of where they are planted. If they count towards your open area, you would have maintenance happening via the council or another statutory body regularly cutting grass, trimming bushes or something like that. It could be that the maintenance is as low-level as what happens in other parts of the public realm.

Mr Dunne: It is certainly complex in Northern Ireland. Any new development is private initially. There is then a long process towards adoption by the Department that can take many years and might never be done. That leaves many areas where it is down to private companies and groups of residents are paying for that contract.

Mr M Harvie: Yes. It is a bit like other parts of the infrastructure in those private developments, such as the road, the sewers and the lighting. They have to be up to a certain standard, and they have to be taken in charge at an appropriate time. Adding SuDS to that list would be one more thing, but you might also remove one more thing. In a lot of those developments, you have a foul sewer and a surface water sewer, and, if the design is done appropriately, you potentially remove the need for some parts of that surface water sewer in that development. That would be one fewer thing to be maintained. It would just mean that there is something else to be maintained but in a slightly different way.

I agree that it is a risk. It is a movement that would have to be done to understand how such things are maintained and looked after differently. Again, there are good examples of where SuDS have been inappropriately designed and placed, and they have then failed and have subsequently been restored or retrofitted with other types. It comes back to the point that Adrien made about the appropriate skills and experience in the SuDS approval body, so that it makes sure that the recommendation for the right type of SuDS is done in the right place at the right time.

Adrien, do you want to —?

Mr Baudrimont: No, you covered it really well. It is a really key aspect. One thing that is probably to be avoided is the future creation of orphan assets, which is where an asset that was supposed to be maintained by a private company is not being maintained because that company does not exist any more. It goes downhill from there, because communities and people living there see an asset that is not functioning. It may be completely derelict. That does not send a positive message at all, which leads to a misinterpretation of what SuDS could or should be. That is a really key point. It is about trying to secure the means to adopt and maintain those features in the long term.

Mr Dunne: It is an important issue. There is an opportunity to get it tied into the legislation to make sure that it works now and in the future.

Mr M Harvie: I agree. If you had an approval body, it could also police the maintenance of those features to make sure they were acting in the right way.

Mr Dunne: Yes. It highlights the need for a single approval body to keep as much uniformity as possible.

Mr M Harvie: Absolutely. Consistency is really important.

The Chairperson (Mr Martin): That is it, gentlemen. Thank you very much for your evidence today. It was really interesting. We covered a wide range of areas in your evidence and the questioning, which is really helpful. We will write to you, Martyn, to get some of the additional stuff that we talked about during the session.

Thank you, Adrien and Martyn, for attending today. We really appreciate it.