Non-return valves: stopping sewage backflow in a flood
Checked 23 Oct 2026
How floodwater and sewage can push back up through drains, and how non-return valves help.
How backflow happens
Editor: write this section from the sources in the front matter (brief section seven).
Where valves go
Editor: write this section from the sources in the front matter (brief section seven).
Who fits them
Editor: write this section from the sources in the front matter (brief section seven).
Sources
- Code of practice for property flood resilience (CIRIA C790) (CIRIA), checked 23 Oct 2026