The initial answer is probably no. If the property is located within the Internal Drainage District then any person must seek permission in advance from the Internal Drainage Board to alter or modify the watercourse under the terms of the Land Drainage Act 1991. This permission is known as Land Drainage Consent. Please report unusual activity and provide a location (street name, postcode or What3Words) to our planning team (telephone 01553 819630 or email planning@wlma.org.uk).  All reports will be treated anonymously. The same rule about works to ordinary watercourses applies outside the Internal Drainage District boundary where the regulator for works to watercourses is likely to be the Lead Local Flood Authority.