According to the latest readings from the Hydrometeorological Administration, dated 2 October, the level of Lake Ohrid stands at 693.36 metres above sea level. The multi-year average for October is 693.31 metres. The difference: five centimetres.

For now the lake is above average, but the water level has been falling steadily for a long time. Only 26 centimetres remain to the minimum permitted level of 693.10 metres. The sharpest drop was recorded between 11 and 13 August, when the water fell by ten centimetres in just two days. The downward trend has continued since, and the retreating water is visible all along the shore.

Five centimetres above average sounds reassuring. But ten centimetres in two days in August is not a figure easily explained by a hot summer alone. Did the drop come from evaporation, from the outflow through the Black Drin, or from both? The published measurements don't say.

Lake Ohrid is protected by UNESCO and is one of the oldest lakes in the world. Its water level is not just a number for hydrologists - it is a measure of whether anyone is paying attention. The next readings will show whether the trend stops, or whether those 26 centimetres to the minimum become the news.