Blue-green infrastructure (BGI) plays a key part in mitigating the effects of climate change, especially in urban spaces— often made of hard, concrete surfaces where water has no other choice but to drain off through the pipe system. In this article, Emily O’Donnell and Andy Barrett continue their discussion on the benefits of green spaces, going on to explore the potential of Nottingham as a Blue-Green city and how to mitigate flooding in Nottingham, and more specifically, the Meadows.

For more information on BGI, check out our introductory article here.

You mentioned that some of your work is around people’s perceptions of the kind of adaptations you are calling for. Can you say a little more about that?

We’ve interviewed people about some Blue-Green infrastructure projects, and people understandably prefer BGIs that are clearly seen as recreational space, rather than as interventions to manage water. There are always issues with open water though, of the creation of ponds as drainage systems; of safety and worry about children drowning in it; of mosquitoes and rats.

It's difficult because everyone has their own opinion; some people like messy nature and other people like it manicured, with cut grass in squares. You're never going to design something that everybody likes, but if you can design something that people can use, people might care less about the aesthetics. If you're saying, ‘I'm putting this in to manage your flood risk’ they'll go, ‘well, my house doesn't flood’. People just don't think about flooding unless they've been flooded themselves. But if you say ‘we're putting these in to green your street, to make it look more attractive, to attract more insects and birds’, then people are interested. It’s all about perceptions. We're never going to win anyone over by talking about water management and drainage.

Detention pond at the Newcastle Great Park Development

Did Covid impact how people feel about local access to green space?

Absolutely. I did a survey on the River Leen in 2021 and lots of people who had never really visited it before, said that it had become their green space, and that it had become important to them at that time. There’s lots of work being done looking at the health and well-being benefits of being near blue and green space, and that's how we need to pitch it to get people interested.

We've probably fallen back into the old pattern where people drive to the Peak District, but not everybody can do that which is why we need more green space in cities.

You say that these spaces are good for our well-being but how can we really measure that? Or is it just anecdotal?

There isn't one metric to measure health and wellbeing, because they are influenced by so many different factors. It's not just about living next to some green space because you might not use it. There is a lot of interest now in the links between climate change and health, which is a focus for future research projects, and the University of Nottingham are forming a research group to try and get some of this work done. I think when the Environment Agency requests funding to do this kind of work there is some measure where they try and quantify some health benefits, such as fewer visits to the doctors, but this does not include many of the social benefits of BGI.

Is this work happening in Nottingham?

There are some projects but it’s small scale. There are some rain gardens in Sherwood, we have some swales here in the University’s car park; there’s the Day Brook Water Meadow project (which is connected to the idea of de-culverting rivers, where buried urban rivers and streams are uncovered and restored to more natural conditions to create new habitats for plants and animals, as well as managing flood risks).

It’s all rather piecemeal and if people build things privately then it’s difficult to log. There’s no map or database of where all the Blue-Green infrastructure is.

Can you tell us a little more about what a swale is?

A natural swale is a low-lying or depressed and often wet stretch of land. You can design swales to funnel water in any direction you want, using gravity.

A rain garden, or a bioswale, like the ones we have in the University of Nottingham car park are generally a few metres long and really look like planters or raised beds. Like a swale, it uses the topography of the land to funnel the water into them and temporarily hold it there. Once the water has been captured it drains into the soil and plants that are inside it. You may have seen them and just not realised their function.

You can find out more about the bioswales in Portland at About Green Streets | Portland.gov and about similar work in East London at A Storm in a Bioswale: Breaking Down Barriers to Nature-Based Solutions | Connecting Nature)

Do we know if flooding is getting worse in Nottingham?

I think it is. I'm sure the Met Office have records that we are getting more rain in the summer, (as well as hotter days, as reported here). There have been more extreme rainfall events, like Storm Babet and Storm Henk, which might not have flooded the city but flooded areas near the Trent.

We also have more development, which means more water on the surface. Unless we're keeping pace in building flood risk management infrastructure, which we're not, then we are going to have more flooding.

It’s not necessarily the overall amount of rain over the course of the year, if we have a lot all at once, then it overwhelms the existing drainage system. If you get a little bit every day, then the drainage system in the city can cope with it. But when you get a big storm, and they are expected to be getting more frequent, then there are challenges.

Groundwater is another issue. We used to extract a lot of groundwater in Nottingham for industry, for instance along the River Leen they had all the dye works. Now that we’re not doing this, and with increased rainfall, the groundwater is gradually rising and people with basements are finding that they are more easily flooded.

Earlier in the year when the Trent broke its banks there were places around Colwick that were flooded for quite a while because there was nowhere for the water to go.

Do you have any advice you can give the residents of the Meadows about what we can do to prepare for potential flooding risks?

To start with, the Environment Agency have a national flood map, so you can check on the flood risk to your property, not just from the dangers of river flooding, but also from surface water and the dangers of flooding from rainfall.

The Trent is obviously very well managed through the city, with all sorts of barriers and embankments, and the risks of flooding for most people is through pipes bursting and water coming up, or from rainfall and flooding along roads.

You can look at the flood risk to your own property through these links:

Check the long term flood risk for an area in England - GOV.UK (www.gov.uk)

See flood risk on a map - Check your long term flood risk - GOV.UK (check-long-term-flood-risk.service.gov.uk)

It’s also helpful to think about how you can make your house more resilient to flood damage.

If you're in an area that floods then make sure all your treasured possessions are upstairs. You can also raise your plug sockets so that if you do get a flood your electrics are not going to get soaked. You'd only do that if you know you're going to get flooded because it's a big cost. But ultimately, pretty much anywhere can flood from rainfall.

Are you hopeful that we’ll see more Blue-Green infrastructure in Nottingham and other U.K. cities?

I think so. I think there's a bit more support at different levels. There is clearly recognition at a national level that we need to manage the impacts of climate change, so we've just got to get on with it.

We can't wait until we have all the answers and all the modelling, we've just got to start building stuff. Some of the things I’ve been talking about are relatively cheap, or at least cheaper than alternatives, like putting in entirely new sewer systems.

But there are so many competing priorities and you wonder where issues like flood risk management fit. It’s often only after a flood when new infrastructure is put in. We're still very reactive.