Water drop test will determine whether you have damage or a leak within your Drainage system.
This test is used to assess the drainage capacity of a complete system, including chambers and gullies. This is a more involved test than others; it can be used to evaluate an entire drainage system, not just individual elements.
The ‘drop’ test is a way to drain test with low pressure. You do this by filling the pipe with water and monitoring the water levels, which you can do at a manhole or pipe access point, over a set period of time.