A marine lake has been temporarily closed after a swimmer became stuck in mud and due to safety concerns for the water quality.
The swimmer was rescued from Marine Lake in Weston-super-Mare by seafront rangers on Wednesday.
The hot weather has also been blamed for a deterioration in water quality. It will now be drained.
North Somerset councillor Mike Solomon said: "We need to be confident that this won't happen again."
Mr Solomon, who is executive member for Neighbourhood and Community Services, added: "With the current spell of hot weather, we're seeing increased usage of the lake.
"Although we've been able to remove a lot of the built-up silt within the lake during the spring, the majority still needs to be removed when we've got the permission to do so."
Weston Marine Lake recently reopened for the summer season after being shut for dredging in the first stage of a £300,000 project to improve the facility.
It is not known how long the lake will now remain closed.
Claire Trevor-Roper, one of the directors of the community swimming group Mudlarks, said: "It's such a shame that we need to close the lake again right at the start of the school summer holidays, but given the volume of silt that still needs to be removed from the lake we shouldn't be surprised.
"While taking a dip or a swim can be a great way to cool off, we all need to take care around the water, understand the hidden dangers that can lie beneath and know what to do if we find ourselves in trouble."
High tides had been used to naturally flush out as much of the lake's compacted silt as possible with new orange and white buoys installed in the lake to mark changes in water depth.
Clevedon Marine Lake, which is about 19km (12 miles) further up the Bristol estuary, was also temporarily closed and drained due to deteriorated water quality on Wednesday.