LAKE BOGORIA

Lake Bogoria (formerly Lake Hannington) is a saline, alkaline lake that lies in a volcanic region in a half-graben basin south of Lake Baringo, Kenya, a little north of the equator. Lake Bogoria, like Lake Nakuru, Lake Elementeita, and Lake Magadi further south in the Rift Valley, and Lake Logipi to the north, is periodically home to one of the world's largest populations of lesser flamingos. The lake is a Ramsar site and Lake Bogoria National Reserve has been a protected National Reserve since November 29, 1973.

Lake Bogoria is located in Baringo County,about 120 km north of Nakuru city and 240 km north of Nairobi. It is in the Gregorian Rift Valley.It was once part of a larger freshwater lake, joined with the current Lake Baringo.As shown on the satellite picture at the top of this page, it is divided in three lobes: a large center one and two smaller ones at the north and south extremities. The two narrower areas separating these lobes are shallow, tectonically controlled sills at Nyalibuch and Mwanassis.

There are contradictions regarding its altitude. Unesco's Ramsar gives 963 m (3,159 ft). More precise  and more prudent , Renaut & Owen 1991 give c. 990 m as of August 1977, but also indicate that the lake's level fluctuates seasonally by 50 to 100 cm; and that it can vary by several meters for short periods, having fluctuated between c. 988 and c. 996 m during the 20th century. Lake-shore terraces around the shoreline, made of coarse angular gravel and angular orthoconglomerates, mark higher lake levels from the Pleistocene and Holocene.They are visible on 45% of the present level, and some are about 9 m above the present shoreline.

In 1991 the maximum length is 17.6 km (10.9 mi) and its width ranges from 0.5 km (0.31 mi) to 3.6 km (2.2 mi)The drainage basin is 700 km2 (270 sq mi)[citation needed].The lowest point of the drainage divide is at 999 m near Loboi village; when the level of the lake reaches that altitude, its waters flow northward in lake Baringo drainage basin.

In 1978 its maximum depth was recorded as 12 m (39 ft)[11] or 11.5 m (38 ft), and Renaut & Owen 1991 precise that this was in the largest sub-basin or lobe; and that the two smaller parts at the north and south extremities were 5.5 m (18 ft) deep at that time.In 2003 its maximum depth is just over 10 m (33 ft) in an area of 3,000 ha (7,400 acres). This is relatively shallow, but nevertheless deeper — and therefore hydrologically more stable — than the other endorheic lakes in Kenya. The Rift Valley lakes undergo regular (and cyclic) changes in water levels mostly in response to precipitation, which is unreliable and unpredictable. In this region, lake Bogoria is the only alkaline lake that has minimal lake water fluctuations, and is used as a refuge for flamigos and other animals when other relatively shallow lakes dry out.Its surface is generally 3,300 ha (8,200 acres) but this fluctuates, essentially according to the amount of rainfall.Most of the rain falls between April and November, and precipitation ranges average about 700 mm on the Loboi plain and 1200 mm on the adjacent highlands. But El Nino years bring increased rainfall and flooding of the lake shores. For example, in 2020 its area increased to about 4,690 ha (11,600 acres):2020 was one of the hottest years on record, but despite depressed rainfall in the short-rains season (October to December, or OND) it also saw a wetter than normal January and February because of the strong positive Indian Ocean Dipole index during that period, and enhanced rainfall during the long-rains season (March to May, or MAM) (that year, Lake Victoria rose to a new record level.