Uganda: Why Rwizi, Ankole's Biggest River Is Drying Up

8 September 2021

Sustained human assault on the environment is depleting key natural resources, exposing them to glaring risk of extinction in the near future.

It would not be discourtesy to say the country's environmental degradation is moving to a scale of epidemic proportions.

In the western region, River Rwizi has lost 60 per cent of its water catchment due to degradation by human encroachment and poor agricultural practices. Rwizi, the biggest river in Ankole sub-region, has a catchment of 8,700 square kilometres.

The river is formed by several wetlands downstream that converge or flow into one another to create the Rwizi that serves 14 districts of Greater Ankole area.

There has been debate about the source of River Rwizi with one theory saying it starts from Sheema district while another account traces the origin in the hills of the neighbouring Buhweju district. The river straddles the districts of Sheema, Bushenyi, Ntungamo, Rwampara, Mbarara, Isingiro, Kiruhura, Lyantonde, Rakai and Kyotera, among others before it moves down to pour its waters into Lake Victoria.

With guidance of local environmentalists and residents, this writer was able to trace the source of Rwizi in a small hill at Rwemigoye in Kyenjogyera, Buhunga sub-county in Buhweju.


The steep Rwemigoye hill sits defiantly between a chain of undulating hills. In the middle of the hill are waterfalls, a precursor to the source, rumbling violently over a rock. You might mistake this for the source of the river. It's not.

Reaching the source requires endurance and manoeuvres through a rough terrain of interlocking rocks a little further uphill. Shortly before the hilltop, a short savanna vegetation sits on a shallow layer of soil defiantly holding loose rocks.

Underneath the rocks, several jets of clean water gush out. This is the source of River Rwizi. These small jets of water form a small stream that rumbles downhill to make Ankole's biggest river.

However, the source is not safe from man's relentless degradation. Crop gardens lie on either side of the stream that grows into a big wetland downhill and splits its waters before intervening streams join it further downstream to form the Kyenjogyera-Mushasha- Kyeirungu wetland system.

Another wetland originating from Kibimba flows through Kajaani, Nsiika and both wetlands converge at Nyakambu on the Mbarara-Sheema boundary to make one water body that is River Rwizi.

However, this water catchment is diminishing due to the rapid degradation instigated by population pressure as people seek more land for farming. The degradation starts right from the source and further downstream along the river course.

During the rainy season loose soils from the banks and surrounding hills, rendered bare by reckless cultivation, are washed into the river, causing silting. The silting and invasion of wetlands is drying up the river's tributaries thus reducing the water flow downstream.

At various locations along the river course, nearly all the wetland systems have been reclaimed and converted into farmlands. At Nyakafumura, part of the Mushasha-Kyeirungu water catchment, the wetland has been drained and converted for crop and livestock farming.

Only a narrow stream of less than four meters wide remains today. Its buffer zones have also been drained. This practice is prevalent in various places where The Observer reached during the field visits.

Kanyabukanja wetland in Karungu sub-county has also been converted into farmland. The entire papyrus vegetation cover has disappeared and the buffer zones have been invaded by man.

The original wetland, which measured about 200 meters wide thirty years ago, has been eroded, leaving only a small stream meandering through a cattle farm of the encroacher.

Local leaders and environmental officers told The Observer that they have tried to stop the encroacher but he has defied all the rules.


He has been arrested several times and even prosecuted in court but the degradation has persisted. When The Observer visited the place this month, the concrete pillars of the National Environment Management Authority (NEMA) erected to demarcate the wetland were right inside the degraded part, meaning the degradation has extended beyond the wetland to include its buffer zones.

A few meters upstream at Nyabirerema foot bridge, a mother of two, Dorotia Birungi, who was found washing clothes in the stream, said about 30 years ago, it was hard to cross the stream at that point because of the huge volume of running water.

She said residents would place two long logs of hard wood to cross. But today due to the persistent degradation in the last three decades, the stream has so reduced that the current water volume cannot even fill up the culvert installed by the district local government.

This writer crossed the stream effortlessly on foot as the water level is hardly above the ankle. The exciting waterfalls about 500 meters upstream are not safe either. They face clear environmental threat as both sides of the wetland have been invaded and the resultant silting continues to reduce the water volume.

The removal of the vegetation cover also exposes the water to direct sunlight, which leads to rapid evaporation and escape into the atmosphere.

Vegetation retains water in a wetland and releases it at a slow rate. Removal of vegetation reduces the wetland's water retention capacity. Water flows much faster and the accelerated drainage leaves the land dry, altering or disrupting the area's weather and climate patterns.

Interviewed for this story in Nsiika, Buhweju district environment officer Clemensia Birungi told The Observer that the district has made several interventions to check degradation of wetlands but has been frustrated by the lack of support from other departments of government such as police and courts.

Birungi said police and courts are slow or reluctant to act on cases of environmental degradation. She said even on occasions when encroachers are arrested and taken to police or courts, they are often released. They come back to continue with the degradation.

Birungi also cited political interference as another impediment to fighting encroachment on wetlands and other water catchments. Many encroachers are influential in the affected areas. Any attempted action on them attracts intervention from some local politicians who frustrate the investigation and prosecution process.

Another obstacle is underfunding. She said government gives a lean budget to the ministry of Water and Environment and what trickles down to the district is peanuts.

Birungi said wetland restoration is proving an uphill undertaking because it's not enforced uniformly countrywide. Some local governments are not enforcing interventions on environment and implementation in a few districts is perceived as selective persecution of the culprits.

"Environmental degradation cannot be fought in isolation. You are fighting wetland degradation here and telling the invaders to vacate but elsewhere they walk scot-free. You get accused of personal vendetta and persecution against the culprits. It makes it hard to implement the restoration of wetlands. The Nyakafumura-Kyeirungu wetland has been destroyed. We arrested the culprits, took them to court but the court declined to visit the locus [scene]. Court ruled that we failed to prove that the accused had degraded the wetland yet there are NEMA pillars showing the de- graded area is a wetland," Clementia said.

Mbarara city's NEMA senior environment support officer Jeconious Musingwire revealed that about 60 percent of Rwizi catchment has been degraded, resulting in reduced water volumes.

A visit to the water treatment plant at Ngaro Mwenda bridge in Mbarara city gives credence to this claim. He said due to degradation, the wetlands no longer have enough water to feed the river. He added that encroachment on wetlands and runoff from degraded hills due to poor agricultural practices have accelerated disposal of soil into the river, leading to silting up and reduced water volume.

However, he said there are ongoing efforts to restore the catchment and save the river.

"Together with development partners, we are focusing on restoration of water resources. We have evicted many encroachers, blocked drainage channels to retain water around, and allow vegetation to grow. We have restored the Nyakambu wetland in Bukiro and Masheruka at the Mbarara-Sheema boundary. We have recovered Kashasha wetland in Rwampara district. Recovery is at 75 percent. Restoration of Bujaga wetland system started last year and we are following up. Recovery is at 30 percent. If we are to restore River Rwizi, all wetlands must be recovered," Musingwire said.

The National Water and Sewerage Corporation (NWSC) principal engineer at Mbarara office Eng. Samuel Akol admitted the river's volume has shrunk and affected their operations.

"During the dry spell, the river levels go down so much that it exposes our foot valves which means they cannot suck water and pump it into the pipes. So, we put sandbags to retain the little water coming in to raise its level to allow foot valves suck it and send it to the pipes," Eng. Akol said.

He said demand for water in the city had gone down during the Covid-19 lockdown in May-June. He warned, however, that following the lifting of the lockdown, demand will go up and water shortage in Mbarara may get worse.

The NWSC spokesperson for Western region Paul Turyamureeba said degradation of River Rwizi has undermined their mandate to purify and supply water. The affected water level has become a big challenge to NWSC in fulfilling its mandate of supplying water.


Turyamureeba said a committee for restoration of Rwizi catchment has been constituted comprising members from the districts that share the river. Musingwire and Eng Akol said through the stakeholder engagement, there are ongoing interventions to restore the river's catchment and water level.

Under this partnership, Nile Breweries has erected gabion walls at its plant in Ruharo in Mbarara, to stabilise the river banks and stop the loose soils from collapsing into the river and silting it. Nile Breweries environment and safety manager at the Mbarara plant Adam Wilson Emaru said there are similar efforts to protect the river catchment upstream in Kakigani in Rwampara district.

"The river's water levels have reduced, but we are doing what we call source stabilisation. The gabions stabilise the banks to stop the silting and also stabilise the water levels to enable us monitor the volume to know how much water is in the river," Emaru told The Observer at the site on the river bank in Ruharo.

"We have erected metering pillars to monitor the water flow. We take readings of the water levels every day and submit monthly readings to the Ministry of Water and Environment for analysis," he added.


The ministry of Water and Environment says government has undertaken statutory decisions to fight further degradation of environment and restore the degraded areas across the country.

"There is a cabinet directive to cancel all land titles in wetlands and the cancellation process is ongoing. Land titles of people living in gazetted forest reserves are being cancelled. We are trying to demarcate all wetlands in Uganda and we are sensitising people on dangers of degrading environment," the ministry's spokesman Charles Muwonge told The Observer during investigations for this story.

This story was done under the initiative supported by Dunia, a CFI (French media development agency) project.

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