The Deep Hull’s Iconic Aquarium
The Deep, Hull's iconic aquarium, juts out beside the banks of the Humber, looking like the tip of The Shard had fallen on its side. As you walk into the tourist attraction, past the abundantly stocked gift shop, near the lifts but not quite as far as the shark tanks, lies a hidden laboratory. I would say ‘secret’, were it not for the fact that a sign above the door announces exactly what it is: “The University of Hull Property Flood Resilience Innovation and Testing Lab”, or PFRlab, for short. An information sign adds: “What’s behind these doors?” reads “Right here at The Deep, work is underway to build a safer, stronger future against flooding. We know floods are becoming more frequent. That’s why we’re leading the way with practical solutions that will help protect people and places”. The doors themselves, however, look solid and impenetrable, and are topped with a ‘Do not enter when lit’ warning sign; it’s clear that this isn’t part of the tourist attraction. I tentatively knock on the doors. And I’m welcomed by the lab director, Stuart McLelland, professor of Water Science at the University of Hull.
Upon entering, it’s immediately clear that this is like no science lab I’ve ever been to before. Technicians on laptops compete for space alongside giant rolls of wire, tubing, stacks of wood, old sandbags and house bricks. It has the feel of a DIY enthusiast’s garage. And then there’s the tank. Taking up the majority of the space is a huge glass-sided, metal-framed 16m long, 6m wide tank, raised a metre in the air, and filled with a fascinating mix of high-tech equipment and household items. Most prominent of which, on the day I visit, are three ordinary household front doors, standing in carpentry frames and fixed in place, but completely devoid of their house.
Outside the not-so-secret University of Hull Property Flood Resilience Innovation and Testing Lab, but are they hiding secrets inside
I step into the tank with Stuart to learn more.
“This is our Total Environment Simulator, which is a big flume tank”, he explains, in a soft Scottish accent offset by a loud orange woolly jumper. “Here in the PFRlab, what we're doing is looking at real-world property features like doors and trying to understand what happens to them during flood events – and how we can make those doors more resilient during flooding.”
Experiments here in the past have included everything from river flow dynamics – turning the entire tank into a gravel riverbed and seeing how sediment and water react at different flood levels (The entire tank can be flooded up to 1.8metres, although Stuart admits he prefers to keep it to 0.8m.) There’s even been extraterrestrial testing here. Prior to the NASA Curiosity mission, the PFRlab was turned into a replica Mars surface to look at “ways water could shape the landscape on Mars”.
The far end of the tank is fitted with a wave machine, and above our heads are sprinklers capable of replicating a range of rainfall conditions. “We can look at low flow rates, high flow rates. We can look at small waves, big waves, all of those different things. We can basically simulate how the real world works and understand the dynamics of that.”
And today, it’s doors, in partnership with Flood Re (see my previous blog with Flood Re’s Martin Lennon). “Essentially what we want to look at is if you have a normal household door, and you expose that to a flood event, how much water leaks through it? So, we've got three different doors set up here.”
Inside the PFRlab when flooded. Picture courtesy of PFRlab.
Standing in a row, with various water flow measurement kit behind them, is a composite door (uPVC plastic, with a wooden filler in the middle), a standard wooden door, and a fire door. “We are doing a series of tests where we fill the tank up to different levels and measure exactly how much water passes through the door.” When the tank was flooded – sadly not on the day I visited, though we have a picture from a previous experiment above – the cheap composite door fared best, followed by the fire door, then the cheap wooden door. But the biggest difference of all came down to which way they opened.
“If you have an inward opening door, which is what we all have normally as our front door, that leaks much more than an outward opening door”, explains Stuart. “An outward opening door lets in 80% less water on average. That is a huge difference. So, if you want to stop flood water coming through a door, one thing you could do is have an outward opening door rather than an inward opening door.”
In a separate experiment, they also tested how effective sandbags were – the standard defence in flood-prone areas – against simpler alternatives such as duct-tape. Sandbags only gave a 60-70% reduction in the amount of water coming through. Simply taping up the front doors, however, was up to 95% effective – as well as being far cheaper and labour intensive. Perhaps surprisingly too, sand bags tend to be single use – once saturated with the odour of flood water, they are only good for the skip.
Amazingly, this is the first time that most of this work has ever done in a controlled lab-setting; the evidence base for domestic flood protection is literally being tried and tested right here, right now. At the other end of the tank, the next experiment being set up is for air bricks – typically the first entrance point for a flood – to test the effectiveness of various brick covers.
Stuart’s wider research at the University of Hull also zooms out to the town and catchment level, and sustainable urban drainage (SuDS). This has included the SuDSlab pilot on the University of Hull campus, where “we installed 1000s of instruments measuring in real time with five minute intervals, telling us everything from groundwater levels through to soil moisture, through to how much rainfwater is coming off roofs” – and the ‘rain to drain’ Doncaster, Immingham and Grimsby (DIG) Surface Water Resilience Project, testing the pros and cons of different SuDS, from rain gardens, detention ponds to downpipes and water butts.
“The work we're doing is really to understand how effective different types of SuDS are. So there are lots of different options for SuDS. you can be looking at things like rain gardens, planters, ponds… in Hull we have features called aquagreens that taking water off the road surfaces and storing it. There are lots of different ways in which we can store water temporarily before it's released more slowly in into the water system”. Done at scale, these “provide community level protection”.
One such project in project in Derringham – an area devastated by floods in 2007 which saw 10,000 properties damaged – uses aquagreens positioned to capture water directed down alleyways and away from homes and businesses. According to the Hull City Council website, “They fill during heavy or prolonged rainfall. This can reduce the risk of flooding as it slows the flow of surface water into the drainage system. Another benefit of this is that it also improves our community green spaces. By giving space back to nature, we make more space for water.” As a nature-based solution, it also creates new habitats for wildlife.
The AquaGreen Flood Alleviation Scheme. Pic: Hull City Council
As for which types of SuD works best, “any SuD is a good SuD”, laughs Stuart. “I think it's more what works best in a particular place, for the problem you're dealing with. Is that a peak flow? Is it a very sudden rapid rainfall event? Or is it dealing with water over like a bigger quantity of water over a longer period of time?”
But they all share one key attribute: making space for water. “When we build our urban environments, we're basically reducing the spaces where water can be stored in the natural world, and we are stopping that opportunity for water to soak into the ground”. So anywhere where we can now, retrospectively, or in partnership with new-build developers, “make green spaces to do those things, that's going to have a significant benefit in terms of reducing flood risks”.
Before I leave Stuart to set-up his next experiment, I ask him if the concept of flood risk has changed in the duration of his career, perhaps from where flood risk used to be confined to known flood catchment areas, to now, in the time of climate change, where extreme weather events can make any house at risk of surface water flood?
“Flood risk has become a significantly bigger issue than it was before”, agrees Stuart, “and that's because of how we've changed the use of land, more urban development, but also changing patterns of weather. There's very definitely changes in rainfall pattern, and those changes in rainfall pattern become really important because if you get intense rainfall events – our drainage systems weren't necessarily designed for that. So, without a doubt, flood risk is increasing”.
This means, he says, that “everybody should be aware of it and think about it. Everybody can use the mappingto understand what their risk is, and what they should do… that's a good practice that everybody should adopt.”
As I leave I wonder where all the water drains to when they finish a flooding experiment in here. There are drains directly below the tanks, he says. But they let it drain out slowly so as not to “disturb the sharks in the tanks next door”. And there’s not many scientists in the world who get to say that.
