Access to Lake Rotomā is being blocked after four-wheel-drive vehicles have continued to drive across the lakebed despite the environmental damage.
Te Arawa Lakes Trust environment manager Nicki Douglas said she was saddened by the damaging activity.
"Restoring our lakes and surrounding environments is a legacy we take pride inand the behaviour continues to go against the hard work everyone is doing for the wellbeing of our lakes, waterways and lakebeds."
Douglas said the risk of vehicles spreading weeds and catfish is high.
Access has been blocked at Rotomā Rift Valley and further barriers will be placed to stop four-wheel-drive and vehicle access to the foreshore and lake.
"Changing the mindsets of those who have enjoyed four-wheel-drive and vehicle access to Lake Rotomā will be challenging and prohibiting four-wheel-drive and vehicle access is a temporary fix."
Local community members raised concerns about four-wheel-drive and vehicle activities, camping and large amounts of rubbish being dumped on Lake Rotomā in November.
Earlier this month the Daily Post reported condoms, human faeces, old mattresses and empty bottles were being left on the lake edge.
Te Arawa Lakes is liaising with landowners, hapū, the Rotorua Lakes Council Lakes Community Board and Department of Conservation to put solutions in place.
The trust encourages anyone who has concerns to report inappropriate behaviour to Te Arawa Lakes Trust at koreromai@tearawa.iwi.nz.
