Lake Jindabyne is nearly 80 per cent full and the Bureau of Meteorology forecast more showers, storms and rain in the Snowy Mountains this week.

Mayor John Cahill said it was marvellous to see the lake full and even better to see the shire so green and productive.

"The high country is in a very good state and the lower country is catching up," Cr Cahill said.

Higher water levels may be inviting for swimmers as summer temperatures rise. The Jindabyne Yabbies Surf Lifesaving

Club helps young people enjoy water sports safely and president Simon Quinn said swimmers should take extra care in the lake.

“With the lake being at such a high level, it is advised to swim in areas that can be easily accessed by wading,” Mr Quinn said.

Shallow lake waters can deepen suddenly according to Mr Quinn, and submerged trees and rocks pose safety hazards.

Mr Quinn said cold lake waters, unsuitable inflatable aids and unsafe diving and jumping added to swimming risks.

“Depths can vary and new underwater obstructions like sand, rocks, branches and rubbish may be present. A broken neck from a diving accident could paralyse you for life.”

Snowy Hydro Limited spokesperson Paul Johnson said Lake Jindabyne had capacity for 140 more gigalitres, or 140,000,000 litres. Flooded parts of NSW are seeing dams overflow but Mr Johnson said this was unlikely at Lake Jindabyne.

“It is extremely unlikely that full capacity would ever be reached in Lake Jindabyne as its main function is to capture and store water that is then pumped up into the Murray side of the Snowy Scheme to generate renewable energy,” Mr Johnson said in a statement.

Mr Johnson said the lake was higher than in recent years but reached similar levels in 2004. He said water levels were unlikely to rise much higher.

“As we have seen in previous years we would expect that Lake Jindabyne will now start to drop over summer and into autumn due to our normal electricity and water commitments,” Mr Johnson’s statement said.