Japanese knotweed on New River path

Does anyone how to report a new outbreak of Japanese knotweed on the New River walk 200 m from the Hampton road entrance?

ESCS.Support@haringey.gov.uk is listed as where to report Japanese knotweed but I have heard back from them that they no longer are interested... despite it still being listed on their website.

Attached picture only shows a small part of the new flourishing crop.