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
Choluteca river basin from this Inter-American Development Bank loan are being used to finance expansion of potable water. A 2003 USAID collaborative project with the Zamorano Pan-American Agricultural School is targeting improved management of water sources in the lower basins of the Choluteca and Negro Rivers in southern Honduras. This program supports small-scale irrigation systems and water-harvesting systems, and also commissioned a detailed basin-wide study of the densely populated Choluteca River watershed to assist decision-makers in improving efficiency of water use, development planning, and resource allocation. More specific program activities include low-cost practices to protect the water supplies, improve water storage for farming