Lake Malawi’s fluctuating waters: A two-faced occurrence to adapt to

By The Daily Times Last updated May 22, 2023

Roads, homes and leisure industry infrastructure which are located too close to the shores of Lake Malawi have been under water in the wake of continued rainfall in an extended season running into April. Such are the contradictory implications abnormal rains and the varying water levels on Lake Malawi can cause on different sectors of the economy.

By Hope Musukwa:

Crops and vegetation have been washed away by runoff causing landslides and gullies along. At the same time, Chipoka Port in Salima, already operating at less than half capacity for over five years, is itching to resume full services in view of rising levels of water in the lake. Electricity Generation Company (Egenco) will need more outflow through the Shire to propel the turbines at Nkula as well as those just turned on at Kapichira to boost power generation. Such are the contradictory implications abnormal rains and the varying water levels on Lake Malawi can cause on different sectors of the economy.

Too much water can damage hydro power equipment on the Shire River as it happened last year when water rose to the brim bringing down the walls of the reservoir. The country plunged into months of load shedding. But also, too little flow cannot push the turbines — resulting in persistent power cuts during lean periods. The unpredictable nature of electricity availability affects pumping of water which disrupts supply, leaving users with dry taps for long periods with no alternative source to potable water.

According to 2018 Unesco Hand Book, “where, when and how much rain falls, can affect people’s health and livelihoods and too much or too little precipitation can have devastating effects”.

The National Water Resources Authority (NWRA) is advising potential developers along the lake to contact the water authority for technical guidance to preempt consequences of overflow on the shore.

According to NWRA “this year the lake levels have taken the highest trajectory since 2010. The continued increase would mean that the country has adequate reserves of water resources to satisfy various economic uses along the lake as well as along the Shire River like generation of hydro power, irrigation, navigation and recreational among others.”

NWRA Director of Water Resources Development and Management Toney Nyasulu says the swings of water levels on Lake Malawi have positive as well as negative economic and social implications to bear. The fluctuating water is affecting tourist infrastructure along the lake. What appears dry land today can be a pool of water in an instant. A temporary jetty at Nkhata Bay built nearly five years ago by Mota Engil is now under water. Chipoka which has been operating below half its capacity is likely to resume full services after water levels have risen high enough to allow docking of deep keel vessels at the Chipoka quay that has been idle for years. The port is the country’s strategic docking harbour for cargo vessels sailing from Tanzania through Chilumba and Nkhata Bay linking the railway line.

Nyasulu says increased level on Lake Malawi is due to both good rains and effective management of the Kamuzu Barrage at Liwonde. The barrage regulates lake levels and Shire River flows to determine optimal releases that satisfy generation of hydropower and conserve adequate water in Lake Malawi.

Austin Mtethiwa and Wilson Jere both from the Lilongwe University of Agriculture and Natural Resources and Mexford Mulumpwa from the University of Malawi in their 2015 study acknowledge that the “oscillations have hydro-ecological and socio-economic implications”.

The fluctuating water level in Lake Malawi is attributed to “tectonic factors- processes that result in the structure and properties of the Earth’s crust and its evolution through time and climatic factors”, according to a study by Damien Delvaux of the Belgian Royal Museum of Central Africa, Department of Geology and Mineralogy.

Lake Malawi level has been rising for over 5 years, a period that has experienced unpredictable, mostly higher rainfall but has not attained the highest level recorded since 2009-2010 rainfall season. As of April this year the lake rose nearly a metre over annual mean level of 24 months ago.

Satellite rainfall data for the period 2009 to 20022 from 10 stations – four from the North and six from the Central – all from catchment areas where rivers flow directly into the lake, was compared with monthly means above seas level (Mals). There is some positive correlation between rainfall pattern and water level fluctuation on Lake Malawi. Previous studies have found that rainfall pattern alone does not have significant influence on the fluctuation of lake levels. A study published over two years ago indicates that out of four variables tested likely to influence water levels, open evaporation came first when combined with “rainfall, inflowing discharge or low frequency climate variability indicators such as Eli Nino in 2016”. ‘Multivariate framework for the assessment of key forcing to Lake Malawi level variations in non-stationary frequency analysis’ was jointly conducted by Cosmo Ngongondo, a professor of Earth Sciences at the University of Malawi and others.

Eli Nino impact lasted until 2017 when the lake started rising again. This is the period when rainfall recorded was lowest after nearly 10 years of decline in a period characterised by floods, drought and hunger according to Oxfam International.

Two hundred streams feed Lake Malawi. But the lake’s primary inflow is Ruhuhu River from Tanzania, according to the Global Nature Fund contributing 12 per cent of the volume. Tanzania river inflow contributes 44 percent, Malawi lets in 46 percent, and from Mozambique comes 10 percent according to Climate Resilient Infrastructure Development Facility (CRIDF), a British aid organization. The Shire is the only outlet.

Lake Malawi is the ninth largest in the world and the fourth deepest. It is Africa’s third largest inland freshwater lake home to more species of fish than any other lake in the world, including at least 700 species of cichlids.

The 220-meter average deep fresh water lake can be peaceful but can abruptly swing to stormy conditions just as its unstable water levels. David Livingstone noted all these in 1859 which prompted the Scottish missionary and explorer to baptize this body of water with bipolar pseudonyms of the ‘Lake of Stars’ and the ‘Lake of Storms’. The lake’s fluctuation of its water levels has been and remains a phenomenon to adapt to, for now and in the future.