Ganges Basin (112,490 km²), West Bengal (71,485 km²), Haryana (34,341 km²), Himachal Pradesh (4,317 km²) , Delhi, Arunachal pradesh(1,484 km²), the whole of Bangladesh, Nepal and Bhutan. Several tributaries rise inside Tibet before flowing south through Nepal. The basin has a population of more than 500 million, making it the most populated river basin in the world. The basin comprises semi-arid valleys in the rain shadow north of the Himalaya, densely forested mountains south of the highest ranges, the scrubby Shiwalik foothills and the fertile Gangetic Plains. Central highlands south of the Gangetic Plain have plateaus, hills and mountains intersected by valleys
Thika River country upriver from the falls. Rhinoceros, lions, and hyenas also resided in the area. Most of the game today relocated either upriver to the Aberdares forest or downriver due to pressure from increased human settlement along the river. Eighty percent of the water supply for Nairobi, Kenya's capital city, comes from the Thika River. Deforestation and overgrazing along the river's heavily populated course have caused soil erosion problems. Sediments have reduced river flow, reservoir size, and water quality. Water quality has also deteriorated due to pesticide runoff. The Thika is part of the Tana basin, which is the most extensively