The iconic Serengeti ecosystem of eastern Africa -- until recently threatened by a major new highway -- is being imperiled again. Here, three eminent Serengeti authorities -- senior staffers Bakari Mnaya and Mtango Mtahiko from Tanzania National Parks, and Eric Wolanski from James Cook University -- tell us how proposed dams on the Mara River and its tributaries could imperil one of the world's natural wonders.
The Serengeti -- a World Heritage Site and living laboratory for one of the world's last great animal migrations -- is facing one of its most serious threats.
The Serengeti ecosystem -- comprised by Serengeti National Park in Tanzania, Masai Mara Reserve in Kenya, and adjoining game-controlled areas that create a buffer zone -- has only one year-round river, the Mara.
During the driest periods, aside from a few scattered springs, the Mara River is the only source of life-giving water for Serengeti's migrating wildlife -- the vast herds of wildebeest, other megafauna, clouds of migrating birds, and the big predators whose sheer numbers darken the African plain.
The Mara River and its tributaries have long been threatened by water extraction, for irrigation and hydropower. A major hydropower project that would have gulped up much of the Mara's flow was shelved in 2001, but remains a potential threat.
On top of this, Kenya is now proposing major new dams on the Mara or its key tributaries. These include:
- The 10-meter-tall Norera Dam, mainly for irrigation
- The 65 meter-high Amala Dam, deep in the Mau Forest, mainly for hydropower
- One or two dams (30 to 70 meters tall each) on the Nyangores River, a key Mara tributary, mainly for irrigation
Tanzania is also proposing the Borenga Dam, though it would occur further downstream on the Mara, past the Serengeti, and thus is of less concern.
Crisis in the Making
There's no question that Kenya's proposed Mara dams could have huge ecological ramifications.
The respected Lake Victoria Basin Commission recommends a minimum flow of 300 liters per second for the Norera Dam, but the proposed Norera Dam would release just a third of that.
The Norera Dam is in a critical location -- on the Nyagores River about 30 kilometers upstream of the Serengeti -- where irrigation is already sucking up much of the river's natural flow. Add the Norera dam on top of these demands, and the Serengeti will almost certainly face ecological collapse during the next major drought.
Think of catastrophic wildlife mortality -- hundreds of thousands of animals dying under a baking sun -- while whirring turbines and water pumps drain away the river's life-blood.
Eco-Engineering at Its Worst
As a kind of half-baked solution to the Norera Dam, Kenya is proposed to build the 65-meter-tall Amala Dam. The idea would be to divert water out of the Mara River, and then store it in another watershed, in order to feed back into the Serengeti during the dry season.
But the Amala Dam will cause its own environmental problems -- flooding and destroying a large expanse of the ecologically vital Mau Forest.
And the waters diverted for hydropower in Kenya would then flood into Lake Natron -- imperiling the nesting sites of three-quarters of Africa's magnificent lesser flamingos.
Kenya's house of cards gets even shakier. For example, the feasibility study of the Norera Dam failed to consider basic elements of its hydrology -- where its water comes from -- magnifying the chance of failure during critical periods.
Just as worrisome is that Kenya's proposal is based on average stream flows -- but rainfall in this region is hugely variable among years. In a drought year, would Kenya sacrifice its own electricity and irrigation to sustain dying wildlife?
And would Kenya consider the needs of Tanzania, which contains two-thirds of the Serengeti, while deciding on its consumption of scarce water?
Don't Kill the Serengeti
If you pointed a gun at someone and pulled the trigger, you'd be guilty of murder. But if you locked them in a room without water, knowing they would eventually succumb, wouldn't you be just as guilty?
That, in essence, describes the failed logic of Kenya's proposed dams on the Mara.
These dams would breach World Bank safeguards. They would defy ecological knowledge. And they would flout common sense.
We know enough to say this: A calamity might not happen tomorrow, or the day after. But surely as night follows day, Kenya's Mara dams will lead to an environmental crisis in the Serengeti.
The Serengeti is the magnet for an invaluable tourism industry, a global icon for nature, and the most important vestige of Africa's great savanna ecosystem. Imperiling its water could well be its death knell. It should be unthinkable.