Landforms

Ranges of mountains with peaks, isolated mountains, hills, river valleys, waterfalls, plateaus and plains form the relief of Mauritius. Mountains are remnants of a big volcano which erupted many millions of years ago.

Volcanic Cone with Crater

Bassin Blanc is well known for the scenic lake nested in a volcanic cone.

Cliff along the shore

Cliff coast has been produced where the coral reefs are found very close to the shore. The waves erode the low lying lava plains. At Pointe aux Caves, the fossil cliff is fronted by a debris of rounded boulders of various sizes which cover the wave-cut platform.

Mountain Range

	The range of mountains forms a ring suggesting that at one time they all belonged to one big volcano. Port Louis - Moka Range is the longest one. Others are the Grand Port Range, Savanne Range and Black River Range. Some of the Mauritian mountains have distinct features; Pieter Both Mountain has a rock perched at the top, while Le Pouce Mountain has the shape of a thumb. Mountains carry names according to their shapes e.g. Lion Mountain in the Grand Port Range has the shape of a sitting lion, Trois Mammelles has three protruding peaks and Montagne Blanche has been named after the grayish white colour of the rocks found on the mountain. There are also isolated peaks like Corps de Garde and Tourelle du Tamarin.

Central Plateau

Inside the ring of mountain ranges, there is the Central Plateau which was formed by lava flows from several small volcanoes. The Central Plateau is higher in the south west and it slopes gradually towards the north and east into an undulating landscape.

Rivers and Waterfalls

The volcanic landscape has been deeply dissected by fast flowing streams which take their sources from the super humid Central Plateau.

The rivers have broad and open valleys on the Central Plateau. On crossing the rim of mountains, they have carved out spectacular waterfalls and deep gorges.

The most spectacular one is the waterfall on River Tamarin, known as “Sept Cascades”.     At Chamarel, Rivière Baie du Cap river has a very scenic waterfall.

Sometimes the hard bend of rocks forming the waterfall shows columnar jointing as can be seen at Rochester Falls.

Coloured Earth

In certain areas, the volcanic tuffs (compacted volcanic ash) have weathered into coloured earth, examples of which can be seen at Chamarel and Mont Blanc.

Gorges

Black River Gorges Over millions of years, water flowing down from Black River has carved these beautiful gorges in that mountainous region due to its steep gradient towards the sea. Even today, the rainfall, which varies from 1,000 mm in the valley to 4,000 mm on the peaks, determines which plants will flourish at each location.

Plains

Outside the ring of mountains ranges are the coastal plains, the largest one is in the North and is known as the Northern Plains. These plains have been formed by quick flowing lavas from volcanoes such as Mont Piton, Butte aux Papayes and Forbach Hill.

The other plains i.e. Flacq Plains, Grand Port and Savanne Plains have been formed from lava flows of volcanoes on the Central Plateau. Most of the Grand Port and Savanne Plains have been formed by lavas coming from the largest volcano: Curepipe Point.

Waterbodies

Midlands Dam, constructed in 2003 in the wetter central part of the island, provides water for the northern districts in response to the growing water demands. The water storage capacity is 25.5 Mm³.

During the past 100 years or so, 10 man-made reservoirs, listed hereunder, have been constructed in Mauritius.

Reservoir Capacity(Mm3) 1 Mare aux Vacoas 25.89 2 Mare Longue 6.2 3 La Ferme 11.52 4 Piton du Milieu 3.0 5 La Nicoliere 5.26 6 Tamarin Falls 2.3 7 Eau Bleue 6.2 8 Diamamouve 4.4 9 Dagotiere 0.6 10 Valetta 2.0   Total 67.37

Islets around Mauritius

The island shelf bordering Mauritius supports a large number of offshore islets of various structural types. These islets play a crucial role in deflecting waves and currents along the coast and hence affect the coastal morphology along main island.

The basaltic islets lie close to the main island with very shallow water in between. The major ones are Ile d’Ambre, Ile de l’Est and Ile aux Cerfs. Several sandy islets are found in the lagoon a long the western coast.

Trou aux Cerfs volcano

Trou aux Cerfs is one of the most well-defined and impressive volcanic structures of the island. It presents a perfect circular depression reaching a diameter of 350 metres at the surface. The crater is about 80 metres deep and its base, which is around 180 metres in diameter, remains marshy all year round.

It is situated in the town of Curepipe and offers a panoramic view. Because of its accessibility, it serves as a recreation centre and is also one of the main tourist attractions.

Rivers

Most of the rivers (streams) of Mauritius are small both in terms of their length and amount of water that they carry. Many streams have sources in the high rainfall regions of the central plateau and flow down slope towards the sea. They discharge large amounts of water only during heavy rainfall and during occasional tropical cyclones.

Grande Rivière Noire

Grande Rivière Noire has cut its gorge back into the uplands and exposes solid bedrock along much of its course. This river is the largest stream to dissect the volcanic shield and the spectacular views from its highland rim are famous.