SWIMMERS have been warned away from Lake Eppalock since high levels of toxic algae were recorded by Goulburn-Murray Water.Levels have been rising for some time but reached dangerous highs this week, prompting recommendations to stay out of the water.Acting infrastructure general manager Andrew Reynolds said the lake was still open for all other activities.“We’ve identified some high levels in the last couple of days,” he said. “We’ve been monitoring for a while but it has only just reached high alert level where it is potentially dangerous to people and stock.”Contact with algae can result in skin irritation; sore eyes, ears and nose; and nausea and vomiting if water is ingested.Mr Reynolds said there were often low levels of algae in the lake but conditions were right for blooms.“Generally warmer weather and high nutrient levels will lead to blooms,” he said. “Current inflows will have washed a lot of nutrients into the water and it has been warmer.”If conditions continue it could prolong the length of the bloom, Mr Reynolds said.“It is an unknown ... the timing is uncertain,” he said. “Some blooms break up within weeks but if the conditions stay right it could be longer.“We continue to monitor levels and when they drop below levels that are hazardous we will issue a notice letting people know it’s safe again.”Lake Eppalock is still open to boating, fishing and sightseeing and while swimming is not banned Mr Reynolds said it was discouraged.“We don’t prevent people from swimming but we do provide them with the advice they need and they have to make their own judgment,” he said. “It’s recommended but we don’t enforce it.”G-MW has also advised water users at Lake Eppalock to seek an alternative water supply for stock-watering and domestic use.