Queen’s Valley Reservoir is reopening following a three-month closure to tackle a rat infestation.
The top car park and entrance can be used again from today (4 July).
Jersey Water sealed it off in April because the area was over-run with rats.
The utility has been trying to deal with a small number of visitors who are persistently feeding the wildlife, drawing the rodents.
Read: 'Really disappointing' ongoing part-closure of Queen's Valley reservoir
Jersey Water say the rat numbers are 'significantly reduced' and 'under control', but it will have to keep a close eye on the situation.
Mark Bowden told Channel 103:
"We are really pleased to be able to reopen Queen's Valley, because we know how much it is valued by the community.
"The closure hasn't had the effect that we would like because people have been circumventing the fencing and the closure of the gates that we have had in place.
"We are working with the police and the public health department to try and get some measures and support that will help us to manage the problem that we have got there.
We are still appealing to people not to take any food up to Queen's Valley and not to be feeding the wildlife because the (rat) population is quite problematic."

Nowacki wins Jersey’s first Commonwealth Games medal in 36 years
Thousands expected at Havre Des Pas Festival this weekend
Commonwealth Games: Nowacki into 100m breaststroke final
Channel Islands face 'physical' Poland test
Price of heating oil and other fuel increase by more than half in a year
Man jailed for importing nearly £600k worth of cannabis in bumpers of his car
Baby born on Guernsey's Marine Ambulance
Drug trafficker who claimed he was the ‘Accredited Dealer' jailed