A trail of destruction has been left at a popular beauty spot following a rampage by thoughtless 4x4 drivers.
Fences were mown down and ground ripped up at the Rivington reservoir estate near Chorley.
The damage occurred at the Terraced Gardens, known locally as the Chinese Gardens, the Lower House Barn car park and in the area of Rivington Pike.
United Utilities owns and maintains the estate and company ranger Hazel Gannaway inspected the damage.
She said: "It is very saddening to see the mess this has caused.
"The fences will need to be repaired and it will take time for the ground to recover.
"This kind of erosion can cause soil to wash off into the reservoir, affecting water quality.
“But the biggest concern is the danger to members of the public.
"Anyone walking in the area would not have expected to encounter these vehicles and could have been seriously injured.”
United Utilities is working with the police and is appealing for anyone with information about the incident to report it.
PC Matt Lee of Adlington police station added: "This is criminal damage and we will prosecute anyone found to be responsible.
"It's a growing problem and we are considering working together with United Utilities on a joint operation to tackle the culprits."