First things first – thank you for clicking on a post about drainage – it’s definitely not the most exciting thing about this project. However, Railway Gardens has just passed another big milestone along the way to construction beginning as we’ve now submitted our Sustainable Urban Drainage application for approval!
Although it has caused us a lot of headaches along the way, getting drainage right is going to be so important, and this is an element of the site that we think is going to turn out to be really interesting and good for wildlife too.
The idea with Sustainable Urban Drainage – also known as SuDs – is to replicate natural systems where rainwater is captured, stored, then slowly released back into the environment. In natural habitats all this work is done by trees, plant roots, soil, ponds and wetlands but when we remove those things, or cover them up with roads and buildings, rainwater has nowhere to go, resulting in flooding, and as the water hangs about up on the surface it picks up pollution from roads and pavements, potentially affecting water and harming wildlife. This animation from susdrain explains it pretty well.
In January 2019 new legislation came in here in Wales requiring developments over a certain size to have a SuDs system in place to help prevent flooding and pollution.
We’ve been supported by ALT Architecture and Arup initially and more recently by Atkins Global to design a SuDs system and, after almost two years of plotting and planning we have now submitted it to the SuDS Approving Body (SAB). Here’s what our SuDs plan looks like:
The blue bits are structures, the green bits are rain gardens. The surface area of the structures is used to calculate how much rainwater we need to manage, and the blue lines with arrows show how rainwater will travel through the site. The whole system requires a lot of work below ground to make sure it all joins up and that water travels – in a controlled way – into the sewer system. This will be one of the first bits of work to be carried out on site.
Our SuDs plan is made up of a number of different elements including:
- Permeable pathing so water can drain away.
- Rainwater collection from the roofs of buildings.
- SuDs planters and rain gardens which store rainwater for plants to use as well as releasing it slowly and improving its quality as it filters through the layers of plants, soil and gravel.
- A green roof on the site office.
While it doesn’t form part of our SuDs calculations, there will also be a small raised wildlife pond on site which is really exciting – who do you think will come and live in it? Anyone who was involved in Edible Adamsdown will remember how exciting it was to spot the frog spawn in the community garden pond each spring!
Although this all feels quite technical (and it is!) it’s also a really practical and beautiful addition to Railway Gardens, and we’ve put together a planting scheme that supports insect species while bringing plenty of colour to the site across the seasons. We can’t wait to start planting up the SuDs planters – will you join us? Sign up to the project newsletter below to stay up to date on how construction progresses. We’ll also be arranging ‘come and see’ days so you can take a look and see what’s happening at different stages of the site build.
SuDs is also going to be an increasingly important feature in homes and communities as climate change causes rainfall patterns to change. As we’ve seen recently, both here in the UK and around the world, huge amounts of rain is falling within very short time periods, causing serious flooding. Building this in now will make the project more resilient over time, and we hope to showcase some creative and interesting ways to make a feature out of rainwater collection! Got any ideas? Let us know!
We could not have completed this essential element of the site design without the support of Thomas Reay from Atkins Global and we’re extremely grateful for his help and patience. Thank you Tom!
If you have any questions, feedback or ideas then we’d love to hear from you – use the contact page to get in touch. You can also sign up to the project newsletter and volunteer list below if you’d like to stay in touch. You can also join us on August 25th for the next online community catchup to hear all the latest news from the project, ask any questions, and find out what others in the community are up to. Register your free place here.