As the owner of a property, you must dispose of waste water in the correct manner.
This means that you must connect the waste water to the public sewerage system via a private drainage pipe.

Rainwater may be an exception to this rule.

Wastewater is

• water that has been contaminated through use,
• water whose properties or composition have been altered,
• precipitation water that runs off from paved surfaces and is collected.

Sewerage systems collect and transport the wastewater. Sewage treatment works treat it and then discharge it into watercourses. In some cases, industrial plants also treat wastewater and discharge it directly into watercourses.

To ensure safe wastewater disposal, wet wipes, kitchen roll or newspaper must not be flushed down the toilet.
Nappies and other hygiene products, as well as disinfectant wipes, should not be flushed down the toilet but placed in the general waste bin. These materials are tear-resistant and do not dissolve in water.
Only toilet paper may be flushed down the toilet.