Drainage ditch is a facility for collecting and discharging rainwater, and its design purpose is mainly to ensure the normal operation of land and water. If a fitness center is built above the drainage ditch, it may adversely affect the normal operation of the drainage ditch, such as blocking the drainage ditch and affecting its drainage efficiency.

Any construction activities on public land need the permission and approval of relevant departments. If a fitness center is built on the drainage ditch without permission, it may be regarded as an illegal building and face the risk of being demolished or other penalties.