PARIS (AFP) - For well over a century, the gallant soldier standing below the Alma bridge has been Parisians' favourite way of measuring the rising Seine when floodwaters strike.

The "Zouave" statue commemorates the soldiers from one of France's African regiments that took part in the 19th century Crimean War, where the Battle of Alma was the first major victory.

For a reason that remains obscure, he has become the favourite way to mark the rise of the Seine and on Friday, Parisians flocked to grab a picture of the waters reaching his hips as floods swelled the river more than 6m above normal levels.

It is a rare sight - the last time the Zouave was troubled by the Seine was in 2010 when mild flooding brought water to its toes.

The greatest peril faced by the soldier came in 1910 when record floods saw the river rise up to his neck.

But comparisons cannot be trusted.

The stone bridge that forms the Zouave's pedestal was originally built for Napoleon III in 1856, but was rebuilt in the 1970s and replaced with a metal bridge.

In the process, the soldier was raised several centimetres, said Simon Carrage, an urban architect.

He says beating the 1910 record would now only require water to reach the tip of the soldier's beard.

While the Zouave remains the popular choice for measuring the Seine's swells, the authorities prefer to use the Austerlitz bridge.

But perhaps that is not as reliable as they would wish, since an apparent equipment fault led to the river's depth being wrongly measured for several hours on Friday.