Paragraph 2

Where an undesignated watercourse forms a boundary between land in the occupation of different persons, the liability of each person under paragraph 1 shall extend only so far as the middle line of the watercourse.

Sub-paragraph (1) shall apply whether the bed and soil of the watercourse is owned by one only of the persons mentioned in that sub-paragraph, or partly by the one and partly by the other, or by some other person, or partly by that other person and partly by one or both of the persons mentioned in that sub-paragraph.