Otago Regional Council (ORC) chief executive Peter Bodeker said farmers from the Clutha area were gaining access to the council's flood and drainage sites and were actively involved in weed raking.
Mr Bodeker said it was concerning, as the farmers were not trained in health and safety requirements.
''There are significant health and safety risks associated with working in, on or near ORC's pumping facilities,'' he said.
There was no indication farmers used harnesses when clearing the sites of weeds.
The ORC has an induction and training process staff are required to undertake before operating the flood and drainage facilities.
ORC staff were advised not to allow unauthorised members of the public to engage in duties at the pump stations.
Normally, ORC staff and contractors undertake weed raking on an ''as-required basis''.
Mr Bodeker said the pump stations were monitored daily.
The ORC will investigate mechanical means to divert weed from the screens or mechanical clearing.
Security will also be reviewed at the sites.
Mr Bodeker advised farmers who thought there was excess weed to contact the ORC engineering officer responsible for the area or the manager of operations in Dunedin.
There were no specific sites in the Clutha area where this was a concern and the reference was in general.
Mr Bodeker said there was no cross-over with the Clutha District Council.
