Staff at the East Yorkshire lake say young people have been ignoring warning signs.
Open water and sea swimmers gathered for organised sunrise events in Hull and Hornsea.
Welton Waters Activities Centre says groups of young people have been gathering near the lake.
Two Ukrainian mothers fled to the UK with their families when the war with Russia started in 2022.
Any local group would need to raise £8000 to fund the purchase of a dragon boat.
Pupils helped design the "sustainable" facility at South Hunsley School in East Yorkshire.
Police are investigating a video showing horses at a stables being grabbed by the mane and ridden.
East Yorkshire councillors are considering using cameras to catch people parking dangerously.
Matthew Simpson died after falling into the Gaping Gill cavern in the Yorkshire Dales National Park.
