Waste management remains a problem in
Uganda. This has caused pollution of the environment including the soil and
water. Edwin Nuwagaba looks at how pollution has impacted on Lake Victoria and
how environmentalists are dealing with the problem.
Back in my secondary school days, we
were taught the properties of water. We were told by the chemistry teacher that
water is actually colorless. And in geography, we were told Lake Victoria was
one of the world’s fresh water bodies and that the areas surrounding it
received regular rainfall with high crop yields. This appears to have
drastically changed.
First, when I visited Murchison Bay
in Luzira recently, I found something different about water. The water here had
turned dark green.
Reason? The experts said Lake
Victoria had been polluted. And the pollution had put the entire lake at risk
of drying up.
The surrounding areas now experience
long spells of heat. And according to experts, Lake Victoria, is now greatly at
risk of environmental degradation because unplanned development around it has
destroyed the lake’s catchment area.
The wetlands and swamps around the
lake have been encroached on and some wiped out. “More and more people have
been moving towards the lake because of its fertile soils and its reliable
rainfall,” said Mr Simon Thuo, a water expert at Nile Basin Initiative.
Expert opinion
According to Mr Thuo, the biggest
urban centres in the country like Jinja, Masaka Municipalities and Kampala City
are located around the lake, therefore, releasing effluent into the lake.
Moreover, the effluent is normally
inadequately treated hence causing significant pollution. This pollution is
worsened by the lack of virgin land around the water body.
Human activities like construction,
cutting of trees and poor methods of farming have denied the lake enough
ability to store fresh water. “The lake needs some virgin land so that the
water can be able to infiltrate and percolate. Water naturally needs to move at
a surface flow for it to be able to come out as sub-surface flow, and this is
the water that feeds our streams,” said Mr Fred Kyosingira, a commissioner at
the Directorate of Water.
The water expert added that when
human beings mess with the catchment area, the hydrological cycle is rendered
incomplete, therefore; the water does not get to filtrate. According to Mr
Kyosingira, if the water does not infiltrate the ground, it causing conditions
like flooding during wet seasons because the rain water simply runs off the
surface.
According to experts, unchecked
destruction of Lake Victoria’s catchment area has exposed the lake and left it
vulnerable to siltation and possible drying up.
Lake dries up
The experts worry that unlike Lake
Tanganyika which is 1,470 metres deep, Lake Victoria’s depth ranges from 80 metres
to 140 metres, therefore; the latter’s exposure to siltation and pollution,
makes it more vulnerable to extinction.
According to the study entitled
“Dropping water levels of lake Victoria 2005″ conducted by the Water Resources
Management Department in the Ministry of Water, the surface flow by far
represents the largest inflow of water to Lake Victoria, accounting for 82 per
cent of the inflow with the rest being contributed by land discharge (water
that comes from the land after it has rained).
This explains why it is very
important not to tamper with the catchment area. And Mr Oweyegha Afunaduula, an
environmentalist at Uganda Nile Discourse Forum, says the lake’s catchment area
has been destroyed by people who have illegally reclaimed wetlands around the
lake.
“Our lake is not so deep. If it
continues to lose more and more water and if siltation continues, it may dry
up,” he said, adding that “And whenever the water
becomes less, it also becomes dirty,
and creates a dirty environment where diseases such as cholera, tuberculosis,
typhoid, fever, diarrhea, anthrax, dysentery and others emerge.”
Besides diseases, Mr Afunaduula said:
“Lake Chad was the eighth largest lake in the world but now it is more of a
swamp than a lake.”
According to Mr Afunaduula, Lake
Baringo in Kenya has become shallow because of siltation. He said the lake has
since reduced from its original depth of nine metres to about a metre.
The adverse effects of the
mismanagement of Lake Victoria’s catchment area are not just for the future.
They are manifest even now. For instance, at Murchison Bay where the water has
turned green, National Water & Sewerage Corporation draws the water which
it supplies to the city and its suburbs.
According to Mr Christopher
Kanyesigye, the quality control manager at the NW&SC, over time, the costs
of treating the water skyrocketed. To purify water today, he said, requires
huge amounts of chemicals.
Yet in 1992, Mr Kanyesigye said, 25mg
of a chemical known as alum (Aluminum Sulphate) was used per litre of the water
they supplied.
By 2003 the alum dose used to treat a
litre of water had increased to an average of 36mg. In 2006, it shot to 50mg
and in 2007 it shot to 65mg. Today, an average of 75mg is used per liter.
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