Yes. The effective operation of septic tanks and other private sewage treatment plants is compromised by discharges of rainwater and, as a result, rainwater outlets from the property should always discharge to a river, stream or to groundwater, perhaps through a soakaway.
Any misconnections that you identify through the use of this site are likely to indicate either a rainwater outlet that is incorrectly connected to your septic tank; or wastewater that is incorrectly polluting the environment.