A Taiwanese man surnamed Chen has claimed that he dropped the mobile phone while paddleboarding in the Sun Moon Lake a year ago; but last week, a worker contacted him to say the phone had been found - its case covered in dried mud.
Chen who said he could not sleep for excitement, added the phone worked thanks to its waterproof covering, reports the BBC.
Taiwan's worst drought in 56 years has dried up one of its most iconic lakes. Chen's story is a rare positive one in the East Asian island, which is facing measures like water rationing due to the severe dry spell. It has also adversely affected its semiconductor industry which is the largest in the world.
Chen said the worker who returned the phone had told him that the Sun Moon lake was seeing its lowest water levels in "50 to 60 years".
Many social media users have been posting selfies at the popular tourist spot in recent days, where the ground in some parts has dried up so much that the mud has cracked.
In other parts of the lake, vegetation has grown over the lake bed, making the area look like grassy plains instead.
Taiwan's dry spell comes after not a single typhoon made landfall last year, the first time this has happened in more than half a century. The typhoons usually bring abundant rainfall to the island.
It has forced officials to implement water rationing measures, affecting more than one million households and businesses in the cities of Taichung, Miaoli and northern Changhua county.
On rationing days, various restrictions are in place, including no-shampoo treatments at hair salons and no car washes at petrol stations.