The 50 mile marker area along a mining road in Papua has become the wettest place in the world. Photo: Freeport

JAKARTA – Records are made to be broken and marker post Mile 50, on a precipitous mining road in Papua’s mist-blanketed Central Highlands, is about to challenge two long-reigning Indian champions for the title of the world’s wettest place.

Over the past five years, the rain gauge maintained by the Meteorology, Climatology and Geophysics Agency (BMKG) and mining company Freeport Indonesia at Mile 50, has recorded an average of 12,143 millimeters (mm) of rain.

That’s 478.071 inches, or 39 feet 10 inches and change, enough to oust Cherrapungi, a town in the remote East Khasi Hills of northeast India, from the current top spot, if the World Meteorological Organization (WMO) endorses the data.

Mile 50 is actually known on Freeport’s maps as Tanaga Panamen, which the company’s website notes is also the location of the only public toilet on the route linking the lowland city of Timika with Freeport’s Tembagapura mining town.

It does, in fact, also mark the point where the road leaves the lowlands and begins the 2,000-meter meter climb to the old volcano known as the Grasberg, one of the world’s most profitable – and most controversial — copper and gold mines.

No chance of a suntan there, with rain falling on an average of 329 days a year. The highest annual rainfall recorded around Tembagapura was 15,457.3mm in 1999, while the highest monthly figure was 2,055.4mm in August 2017.

Clouds shroud the peak of the Grasberg volcano. Image: Wikipedia

Almost every afternoon, a thick mist descends over the mountains, stopping all helicopter flights into the town and forcing mine staff from the lowlands to take the three-hour ride over the narrow gravel carriageway that is often subject to rebel sniper attacks.

Freeport environmentalist Gesang Setyado says the high, steep mountainsides create a phenomenon known as the “orographic effect”, in which rain-sodden clouds moving in from the sea and across the coastal plain are abruptly forced upwards.

For all the heavy rainfall, however, Freeport’s milling operation has to rely on water siphoned from the nearby Ajkwa River, the same fast-moving waterway that carries the Grasberg’s tailings downhill to a sprawling lowland deposition area. 

Building dams to store the huge amounts of water required is out of the question because of the nature of the terrain and the risk of earthquakes. According to one engineer, any prolonged dry period can have a critical impact on mine production.

Papua has never figured on the list of the world’s 10 wettest places, although in 2014 data portal IndexMundi placed Indonesia in ninth place, directly behind Malaysia and Brunei, among 186 countries with the highest annual precipitation.

Even the 24/7 Wall St website, relying on data from the Global Historical Climatology Network, a program of the US Centers for Environmental Information (NCEI), failed to include Papua among the supposed 50 rainiest places on earth.

Separated by 15 kilometers on a high plateau in India’s Meghalaya state, Cherrapunji and the tiny settlement of Mawsynram (population: 350) have always been considered the globe’s wettest places, routinely recording more than 460 inches a year.

A rainy day at Mawsynram village in India. Photo: Pinterest

Cherrapunji is the current holder of the two-day world rainfall record, according to the WMO. On June 15-16, 1995, 2,493mm (98.15 inches) fell on the city of 10,000, exceeding the previous record of 2,467mm dumped by a tropical cyclone on the Indian Ocean island of la Reunion in April 1958.

Weather experts say the Khasi Hills, rising to a height of 1,400 meters, catch the full force of the southwest monsoon blowing off the storm-prone Bay of Bengal between May and October; July alone averages 3,050mm or 120 inches.

This year may also have another new wettest place challenger in Mahabaleshwar, a hill station in Western Ghats, a mountain range 2,800 kilometers away from Cherrapunjki on the west coast of the Indian peninsula that fields moisture from the Arabian Sea.

According to the Guinness Book of records, Cherrapunji holds the all-time records for the highest monthly rainfall (9,300mm, or 366 inches, in July 1861) and the highest annual rainfall (26,461mm, or 1041.7 inches, between August 1860 and July 1861).

Other perennial contenders for the title over the years have been Tutunendo in central Colombia and the Cropp River on the west coast of New Zealand’s South Island where a national record-breaking 42 inches of rain fell during a 48-hour period in March last year.

Further south, the popular tourist destination of Milford Sound has long been recognized as the country’s wettest location, with remote parts of surrounding Fiordland and Westland in the far southeast estimated to receive as much as 630 inches a year.

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