A pioneering project in Llanelli, South Wales, has showed that retrofitting Sustainable drainage schemes or “SuDs” across a large built-up area can be done, and can save money.
A paper published in the latest ICE Civil Engineering Journal explains how the coastal town’s combined sewage system led to frequent flooding. It faced costs of £377M for building further flood water storage, and Welsh Water found it could achieve the same result for a quarter of the price using Suds. Author Christopher Ellis of Arup said: “A modelling assessment was undertaken to develop a pioneering, community-focused strategy based on retrofitting Suds. While the systems are small scale, mostly road-side swales and planters, they have performed better than expected and have significantly ‘greened’ the town.”
Ten schemes have been completed so far at a cost of £15M, these have already cut sewer overflows by nearly 40%.
- ICE members can access ICE Journal papers here