Monday, January 27, 2020

Flooding in and around Ruaha National Park


Checking the flow rate of this causeway. We did not cross.
This January we received an abnormally large amount of rainfall in the area leaving parts of Ruaha National Park and the surrounding area (our work area) inundated. Speaking to locals they say it's a 50 year flood with flash floods from the higher areas to the south. Riverbanks were widened after debris built up behind bridges and eroded riverbanks to the point where all bridges to the park were impassable.
Map of the road to the park. Iringa to the east (right) and he park to the west (left). Upper road in the diamond shape is "Never ending road" with the Madogolo bridge (star) and the southern road is the village road with Tungamalenga Bridge (star). The left most star is Karavati Nane, a causeway near to the Great Ruaha River, the lifeblood of the park.
This early and heavy rain was predicted due to a meteorological phenomena called the Indian Ocean dipole. It's also referred to as the "Indian Nino" since it has similar causes and effects as the better known El Nino in the Pacfiic. It's the cause for Australia's extreme dryness this year (exacerbating bush fires) and the deluge of rain to hit east Africa.

We happened to be in the park when the rains began to fall. We all woke up at 3am on Friday the 24th and were shocked at the intensity of the rainfall. One lodge in the park measured 91ml (3.58 inches) in a three hour period, which according to my cursory internet research, is a shit ton of rain. We prepared to leave but we knew something wasn't good when we got to the Great Ruaha River Bridge. The water was higher than we had ever seen it and we were both overwhelmed with the energy of the water. We nearly always stop at the bridge to birdwatch so it's a place we are very familiar with, and to see it suddenly overpowered by a mass of water was incredible. It was one of those moments where nature makes you feel so small and one is just in absolute awe.
Bridge pumping with water.
Bridge under normal wet conditions.
When we reached a causeway called Karavati Nane we realized that we would not be able to pass. We were behind one vehicle full of rangers and I think we both kinda gave each other looks like if one went the other would follow, but neither was going to go first. The water was flowing fast enough and high enough that I wasn't going to try and within an hour there were about five cars surveying the area.

We went puttered around the area for a few hours and then returned at 2pm. The water still hadn't gone down, in fact it looked like it had almost gotten higher. The rangers admitted they weren't sure what was going on but were sure it'd be down by four or six pm. We were also hearing rumors that the bridge at Tungamalenga was down and the bridge at Madogolo was still covered with water meaning people couldn't even survey the damage. Ana and I agreed to head back to Jabali and at least relax in the afternoon and hopefully we'd have access to more information coming in.

That evening we received information that the river had still not receded. We went out the next morning to survey the scene and the water had actually increased! We did receive confirmation that the Tungamalenga bridge was down but Madogolo bridge was still covered in water. In the evening the news was the same, water was still at the same level.

Two days later, the water finally began to recede and damage was extensive. Karavati Nane had a large section that had collapsed (see below) and this was made worse when a team came to fill it with rocks and collapsed another section of the causeway that had presumably had its base eroded beneath it leaving it unable to support a gigantic truck loaded with stones. 

Causeway with some damage
Causeway with some self inflicted damage (face palm)
When we returned to Jabali we decided to face reality and discuss our plan for getting out. The prospect of quick action to repair various bridges was low. We'd heard that people were crossing by foot at Tungamalenga and then heard that the village leaders had stopped it due to safety risks. Two people were confirmed drowned by the floods and two more were missing. Multiple villages west of Tungamalenga were cut off. It was still raining and looked like it was still raining in the catchment area of the rivers. We decided to leave our car in the park and to book a flight to Iringa the next morning.

When we showed up for the flight it was raining. The flight was an hour late and we heard someone call the pilot who reported he was delayed because of the rain and the clouds. When he landed he took us aside and said that it was doubtful we could land in Iringa due to the heavy cloud cover and rains. He did say he could take us to Dar es Salaam but that was just compounding our problem. Ana thought this might be wise since we could at least take the bus the Iringa from Dar. We were worried that the airstrip was getting water logged and if there was another huge rain we might really be stuck. We then got an update from one of the safari drivers that Karavati Nane was passable and we decided to try to cross the river.
Work on Karavati Nane.
Karavati Nane was passable by the slimmest margins. When we got to the gate we met a tourist that had come from surveying the river. He hadn't the slightest clue what was going on and I felt bad for the poor guy as he seemed to be under the impression they'd be able to drive across in a day or two. I didn't know what to tell the poor guy so wished him luck and told him we were going to try to ford the river, at which point he looked horrified.

When we reached Tungamalenga bridge the damage was shocking. The bridge had not been swept away, rather the river bank had widened by as much as the length of the bridge on both sides. It was nearly unrecognizable. To add to the drama, a government representative was coming to survey the damage so what appeared to be the entire village was out at the river. When they spotted me and Ana they were immediately interested, especially when they realized we were going to cross the river.
Tungamalenga Bridge
Tungamalenga is a village we work with so we knew everyone there. The village leader was extremely concerned that if we drowned our embassies would be involved but we assured him we could swim well and wouldn't take unnecessary risks. People indicated that we could cross a bit down river so we walked, and in a very nervous moment I had to laugh as about a hundred people followed us in unison on the opposite bank of the river.
Crossing point.

Getting in there!
I felt a little better when I saw a rope strung across, as well as a gentleman cross with a bicycle and another with a crate of beer. Granted, they were struggling and they were solidly built human beings, to say the least. One guy offered to carry our big bag and escort us across. Ana was initially insistent she didn't need assistance but as we got further into the river she extended her hand to our guide! The water was quite strong at a few points but overall was not bad.

When we reached the other bank there were some cheers and celebrations from some of the people we know well. One of our staff members had just crossed and he was quite pleased to have seen us there. We had a project vehicle meet us in Tungamalenga and drove it to Iringa, leaving our car for another day....


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