Whilst there have been a lot of "come on, get real" comments, there is an argument for the council to do things properly, rather than a cheap bodge job. It's more than likely designed to keep people out, but I suspect if you posted a closer picture, it'd show that it's more decorative than actually functional.
It could be argued that the council have been honest in saying that no work to the sewage plant was intended, and a "safety fence" doesn't break this original statement.
As the council are normally judge, jury and executioner, I suspect you're knocking your head against a brick wall, but if the council know that they'll have a long battle on their hands, they may decide to errect a more sensible fence the height of the hedge instead.