As the landowner you have riparian rights which actually say you must maintain watercourses on your property.
If it's your ditch, then yes, you can clear it.
I'd be thinking, what's the worst they could do? Take you to court and request damages or make you reinstate?
Can't be right, round here I have never seen the environment agency clear anything out...........
Don't think they know what a 360 is, all they do is ride round in white or silver trucks......
Any idea of cost? There is about 100 metres to do. Man with 13 tonne, 360 for 2 days?