Colwick Park swimming events hit by blue-green algae

Colwick Lake is popular with open water swimmers and dog walkers

A number of open water swimming events are under threat after a rise in algal blooms at a lake in Nottingham.

Colwick Lake is closed to bathers until blue-green algae levels have consistently dropped to a safe standard, the city council said.

Algal consumption can cause vomiting, diarrhoea and breathing problems.

The authority's head of parks said more tests were needed until the water is declared safe but events "will not proceed" at this point.

'Disappointed'

"Occasionally during hot weather when the water temperature rises algal blooms can start to grow beyond what we call safe bathing standards," said Eddie Curry.

"Disappointingly we have got a number of aquathlons and open water swims booked throughout July and August.

"At this point those events will not proceed until we've got the all clear from the Environment Agency."

The last test showed the water quality was below the "danger zone" but Mr Curry said a further two tests were needed before it was safe for people to swim or allow dogs into the water.