We may not be able to determine how often or how heavily it will rain, but we can decide how we will respond to rainfall and drought. Climate change – with an expected increase in both downpours and droughts – is raising the urgency of adequate rainwater storage and management. Together with the municipality of Enschede, the Vechtstromen Water Board and a number of Creative Technology students and alumni, Richard Bults of the UT is developing a new rainwater management system: the ‘Rain Tower’, a network of smart rainwater buffers (SRBs) that can self-adapt their storage and management capacity to weather forecasts and conditions.
Three million litres of water
‘The Rain Tower is a new rainwater management solution that can complement other existing innovations and techniques,’ says Project Leader Richard Bults. ‘If the current pilot projects are successful and the concept reaches full development, we expect to realize a total additional storage capacity of three million litres of water in Enschede in the coming years.’
By comparison, the infrastructural solutions the municipality is working on are expected to provide an additional storage capacity of around 7 million litres. These measures include the construction on various sites in the city of so-called Water Drainage Infiltration Facilities (‘WADIs’ in Dutch), and the installation of a 700-meter-long sewer pipe under the Oldenzaalsestraat. However, a capacity of 7 million litres is still not enough to prevent flooding in the city, especially under anticipated future climate conditions. With 70% of the rainwater that is drained off through the sewer system coming from private properties, the help of Enschede’s citizens is vital. The Rain Tower provides a means of making it happen. Bults: ‘Among the Rain Tower’s strengths are the fact that it is cheap, it actively involves residents and businesses in water management, and it is easily scalable.’
How it works
The Rain Tower is set to become an extensive network of smart rainwater buffers: smaller ones for private residences, larger ones for businesses. Bults: ‘The computer-controlled storage tanks constantly monitor local weather forecasts. If a downpour is predicted, they can completely or partially discharge their contents a short while before the shower starts, thus freeing up storage capacity. The fresh water is then stored for use in the next dry period.’
After a pre-pilot involving seven 250-liter buffers, a pilot with around 25 buffers placed at private residences will start half way through this year. A second pilot in 2020 will include an XXL version of the buffer: a 20,000 litre buffer for industrial sites. Bults: ‘Water storage in public spaces is rapidly developing. With the Rain Tower we have chosen a different approach: water storage in private areas, near homes and businesses.’
Devised by students
The idea for the smart rainwater buffer originated mid-2016 during the ‘Twentse Creathon’, an event during which students were given 24 hours to come up with solutions for urban climate effects. A group of students of the UT’s Bachelor’s programme Creative Technology (CreaTe, for short) came up with a smart rain barrel called the ‘Ensketon’. CreaTe’s Graduation Project Coordinator, Richard Bults, recognized an opportunity and involved other CreaTe students and alumni to further develop the idea though various graduation projects. The municipality of Enschede and the Vechtstromen Water Board contributed with knowledge and funding. Less than three years later, the first (pre-)pilot projects in Enschede are in full swing.
Grant application Horizon2020
Before the Rain Tower can reach its full potential and become usable in other cities or even countries, a lot of questions need addressing, Bults emphasises. For example: How do you deal with incorrect weather forecasts? What would be the best incentive for citizens and businesses to start using SRBs? With so many SRBs and owners involved, how do you guarantee a stable, consistent storage capacity? How can the system best be used for watering in the event of a drought? In order to research these and other questions, the UT and the city of Enschede together have applied for a Horizon2020 grant, the European Union’s largest funding programme ever in the field of research and innovation.
Bults: ‘The Rain Tower is a complex concept, because it involves so many different factors, locations and stakeholders. And the more the Rain Tower network spreads, the more complex it becomes. But the enthusiasm and commitment of the municipality, the water board and the students and alumni we’re working with are impressive. All the steps we have been able to take up to now suggest we’re on the right track. Our hope and ambition is to be able to place around 4000 SRBs in Enschede between 2020 and 2025. And with strong social entrepreneurship, we think this may just be the beginning.’
IR.ING. RICHARD BULTS
- Coordinator Graduation Projects for Bachelor’s Programme Creative Technology, SmartXp supervisor and staff member of the Faculty of Electrical Engineering, Mathematics and Computer Science (EWI), University of Twente
- ‘Rain Tower’ Project Leader
- Studied Technical Computer Science and Telematics at the University of Twente
- Fields of interest: Climate adaptation, rainwater management, heat stress monitoring, information management, (tele)monitoring, sensors, actuators
Bults: "You could say I am a ‘climate change believer’. In my role at the UT, I get to share this conviction with students. It is incredibly inspiring is to see that students are already very aware. They realize there is a lot at stake and they want to contribute to improvement; with our research and projects, we can help them find concrete points of connection. Everyone knows about young climate activists like Boyan Slat and Greta Thunberg, but among our students I come across likeminded people, who combine idealism with action. It makes my job with the Creative Technology programme very special."
