Quick Overview of the Mara River in Tanzania

Quick Overview of the Mara River in Tanzania

The Mara River in the Mara Region of Tanzania and the Narok County of Kenya lies across the Maasai Mara/Serengeti National Park ecosystem in the migration path of hooved animals.

The River’s Path

The Mara River is situated in both Tanzania and Kenya. Approximately 35% of the river’s 13,504 sq km basin is in Tanzania, and 65% in Kenya. Its source is in the Kenyan highlands, and from there, it flows for approximately 395 km. The Mara River starts at the Mau Escarpment and runs towards Lake Victoria, where it drains.

The Mara River’s basin can divide into approximately four administrative and/or land use units.

The River’s Regions

The Source: The Napuiyapi swamp (where the Mara River originates) is situated at 2,932 m in the Kenyan highlands. Its main perpetual branches are the Nyangores, and the Amala streams, which flow from the Mau Escarpment situated west. This region supports forests, small-scale agriculture (up to 10 acres), and medium-size farms (approximately 40 acres of mainly tea).

Kenyan Rangelands: This area is home to the Nyangores and Amala streams which flow from the Mau Escarpment to join together as the Mara River. The newly formed Mara River then curves through gaping savannah grasslands. These grasslands are ruled mainly by group ranches of the Maasai tribe who use them as livestock pastures and small to large-scale agricultural land (over 40 acres). The Loita Hills are also situated in this area alongside four important branch stream basins of the Mara – the Engare, Engito, Sand, and Talek rivers.

Protected Areas: Once the river reaches the internationally-known Maasai Mara National Reserve, it merges with three of the above mentioned branches. The river continues to flow until it reaches the Serengeti National Park on the Kenyan-Tanzanian border, where the remaining branch (the Sand – also known as Longaianiet – River) joins it. Human activity is restricted to wildlife viewing.

The Mara Region: The Mara River flows downstream from the Ikorongo Game Reserve, which borders the Serengeti National Park. It curves southwest, where after the main river divides into different branches which feed the Mara wetlands. These branch streams and wetlands continue downstream for approximately 70 km.

The primary use of land in this part of the basin is for small-scale livelihood farming. Humans and livestock crowd the area.

The Mara River is categorized as a functional and ecological river related to socio-economic activities in Lake Victoria and beside the River Nile. It is one of ten basins that drain into and feed Lake Victoria.

Altitudes and Ranges

Bridge crossing Mara river between Tanzania and Kenya
Bridge crossing Mara river between Tanzania and Kenya

The Mara River basin is between 1,134 m and 2,932 m high, with the highest point at its sources in the Mau Escarpments and its lowest at Lake Victoria.

Rainfall in the regions of the Mara River is unpredictable. The different regions receive rainfall at varying times of the year. The rainfall season in the Mara River regions has two peaks, with mid-March as the starting date for the long rains, April for its peak, and June for its end. The short rains fall between September and December.

The amount of annual rainfall that the Mara River receives varies based on these altitudes. The lowest area around Lake Victoria and the low Loita Hills of Kenya receive approximately 700 – 800 mm of rain. The transfrontier savannah grassland (situated in the middle) averages approximately 900 – 1,000 mm. Around the highest point at the Mau Escarpments, rainfall averages between 1,000 – 1,750 mm.

The Effects of the Mara River

Mama hippo with her calf resting on Mara river, Kenyan side
Mama hippo with her calf resting on Mara river, Kenyan side

While the Mara River may appear shallow during dry seasons, it can swell to double its size once heavy rainfall has occurred. During this time, it is an essential water source for grazing animals in the reserve. However, it can also create rapids within the river. When this happens, predators who cannot cross the river to hunt experience food shortages.

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