The news comes after a man died while trying to save a nine-year-old girl who got into difficulty in the water.
Carl Storer, 21, from Tamworth, died on June 30 after being recovered from the reservoir in Burntwood.
Now complaints have been made about a pontoon which has since appeared on the water with a bench stuck on the top.
A park user, who wanted to remain anonymous, said: "This thing has been floated out into the middle of the water and you just know that is going to be too tempting for some kids to swim out to.
"It is unbelievable after the recent tragedies at Chasewater and elsewhere."
Staffordshire County Council said the owner has been asked to remove it as soon as possible.
Mark Winnington, Staffordshire County Council’s cabinet member responsible for Chasewater, said: “We are aware of this pontoon, which belongs to one of the authorised users of the reservoir.
"Its purpose is not for swimming, but we’ve asked them to remove it as soon as possible.”
It is not known who owns the pontoon.