Katwe craters

The first written report of Lake Katwe was penned by Speke, who heard second-hand about a legendarily wealthy source of salt close to the base of the Mountains of the Moon. By that time, the lake had been mined for at least 400 years, and with salt being regarded as more valuable than precious metal in pre colonial Uganda, control of this prized possession regularly shifted between the region's different kingdoms. Indeed when Speke visited Uganda in 1882, Lake Katwe had for some years been part of Toro, but in the late 1870s it was recaptured by Omukama Kabalega, a coup that led to the first military confrontation between Bunyoro and a combined British-Toro expedition led by Captain Fredrick Lugard^[8]

Lugard arrived at Katwe in 1890 and recorded that: 'Everywhere were piles of salt in heaps covered with grass, some beautifully white and clean'.^[8]

Modern salt making continues and can be seen at Lake Katwe or Kasenyi Crater where local residents maintain a systems of salt ponds. The craters can be visited by more adventurous travelers to the national park. Best viewed from Katwe Explosion Craters Track, a rough, single lane dirt track that climbs through the hills and runs along several crater rims.

The crater area lies along the Albertine Rift, inside the Queen Elizabeth National Park landscape north of Mweya.^[9] Dozens of extinct craters occur along the “Crater Drive” route between Kabatoro and Crater gates.^[10]

The Katwe-Kikorongo volcanic field covers about 180 km² and includes about 80 foiditic tuff cones and maars, with several crater floors holding lakes.^[11] The crater landforms formed through explosive magma-water interaction (phreatomagmatic activity), producing maar craters and tuff cones.^[12] The Global Volcanism Program reports no confirmed Holocene eruptions for the field, and the last eruption remains unknown.^[13]

Published summaries describe wide variation in crater size; the largest reach about 3 km in diameter and about 100 m depth.^[14]

Lake Katwe occupies intersecting craters immediately north-east of Lake Edward, forming a shallow water body about 3 km long.^[15] Lake Katwe lies at about 885 m elevation and reaches a maximum surface area of about 2.5 km²; reported depth ranges from about 0.4 m to 1.6 m, with a reported circumference of about 9 km.^[16]

Munyanyange Crater Lake lies near Katwe town and functions as a seasonal wetland; when full, reported surface area reaches about 40 ha, and surveys treat the site as a long-term bird roost location.^[17]

Salt extraction at Lake Katwe forms a long-running livelihood activity in the Katwe-Kabatoro community. Uganda Wildlife Authority materials describe salt extraction using evaporation pans since the 14th century, supported by local guiding for visitors entering the crater floor.^[18]

Engineering and geochemistry literature describes production around the lake through traditional solar evaporation, with over 10,000 salt pans reported around the lake margin, and seasonal harvesting reported from February to April and from July to September.^[19] The same source reports a preliminary estimate of about 22.5 million tonnes of crystalline salts in Lake Katwe (citing a 1997 Uganda Development Corporation study), and reports current production at about 15,000 tonnes.^[20]

Soda and saline crater lakes in the Queen Elizabeth National Park landscape support waterbirds, including seasonal congregations of flamingoes reported in Uganda Wildlife Authority visitor information materials.^[21] UWA monitoring reports record Lesser Flamingo at Munyanyange (July–August 2019) and note long-term declines in recorded species associated with lake drying and human activity pressures.^[22]

Crater landscapes form a major scenic feature in Queen Elizabeth National Park. UWA describes a 27 km Crater Drive between Kabatoro and Crater gates, with viewpoints along crater rims and an information centre at the Queen’s Pavilion near Crater Gate.^[23] UWA materials also describe guided visits at Lake Katwe to view salt extraction and note migrating lesser flamingo at adjacent Lake Munyanyange between August and November.^[24]

Research on Lake Katwe brines describes carbonate-type hypersaline chemistry and mineral salt precipitation during evaporation, with implications for salt quality and processing methods.^[25] Geological summaries also document the field as the largest volcanic field in a chain of Western Rift volcanic fields in Uganda, with maars and tuff cones extending between Lakes Edward and George.^[26]

• Lake Katwe
• Queen Elizabeth National Park
• Albertine Rift