Report lifts lid on Rusizi hot springs mystery

The report estimates that acidic water and chemical compounds found in rainwater and underground water were 85 per cent the cause of the disappearance while earthquakes, dynamite explosions and other reasons took 15 per cent.

Tuesday, September 08, 2020
The hot springs suddenly disappeared last month. / Photo: Courtesy.

A new report released by Rwanda Mines, Petroleum and Gas Board on Monday, September 7 suggests that earthquakes, and dynamite explosions might have acted as ‘trigger’ and ‘accelerator’ for the disappearance and deviation of the one-hectare hot spring pond in Rusizi district.

A hot spring is formed when hot water is produced by the emergence of geothermally heated groundwater that rises from the Earth’s crust.

The hot water vanishing in Nyakabuye sector happened in the mid- August and since then, geologists and seismologists launched a probe into the incident.

The water was serving as a tourist destination and as physiotherapy for sick people.

The report suggests the two as triggers because the limestone rock under the hot spring pond was already broken down by acidic water and chemical compounds found in rainwater and underground water creating sinkholes ‘cavern system’ into which the hot spring pond water sunk and disappeared.

The report estimates that acidic water and chemical compounds found in rainwater and underground water were 85 per cent the cause of the disappearance while earth quakes, dynamite explosions and other reasons took 15 per cent.

Earthquakes happened on September 16, 2020 and August 24, 2020. Dynamite explosions in the area are used three times a month.

Jean Claude Ngaruye, Mining Exploration Division Manager at Rwanda Mines, Petroleum and Gas Board said "Earthquakes and dynamites might have shaken the already weakened rock, land and mud under the hot spring pond which ‘triggered and accelerated’ the time of deviation and disappearance of hot water. But the root causes is the nature of rock broken down by chemical compounds.”

This is why nature of the rock broken down by acidic water takes a big percentage and other reasons such as earthquakes and dynamites take 15 percent of disappearance factors, he explained.

Time bomb

Meanwhile the geologists and seismologists have warned that the ‘limestone rock’ under the hot spring in the area is like a ‘time bomb’ that could explode any time in the future even if there are no earthquakes and dynamites.

"This is because limestone rocks by nature gradually create sinkholes in them which can accidentally cause land to sink and kill people who live on that land. The accident could still happen in the future in that area if precautions are not taken,” the report explained.

The report recommends a thorough study of the flowing and circulation of hot spring water in Rusizi and its affiliated caves because they could collapse any time in the future and cause accidents while ‘trying to create another pond’.

It also recommends turning hot spring water into electricity, swimming pools and others that could attract tourists.

The report shows that in order to restore the previous hot spring by building a dam is very expensive since it requires sophisticated equipment that ensures safety.

Another hot spring pond can be created elsewhere and be used as a swimming pool for tourists,” recommends the report.