, Nepal.|right The basin of the Bagmati River, including the Kathmandu Valley, lies between the much larger
Gandaki basin to the west and the
Koshi basin to the east. These adjacent basins extend north of the main Himalayan range and cross it in tremendous gorges, in fact, the
Arun tributary of the Koshi extends far into
Tibet. The smaller Bagmati rises some distance south of the Himalayas. Without glacial sources, its flow is more dependent on rainfall, becoming very low during the hot season (April to early June), then peaking during the monsoon season (mid-June to mid-August). In these respects, the Bagmati system resembles the
(West) Rapti system lying between the Gandaki basin and the
Karnali basin in the far west of Nepal. The Bagmati originates where three headwater streams converge at Bāghdwār Falls (), where the water flows out through a
gargoyle shaped like a
tiger's mouth, situated in
Shivpuri Nagarjun National Park near
Sundarijal in
Nepal . This lies above the southern edge of the Shivapuri Hills, about northeast of Kathmandu. Here the Bagmati is wide and swift with a high load of
suspended solids, giving it a grey appearance. and sewage-laden
Tukucha Khola. Then the river bends south and the Bishnumati enters from the right at Teku Dovan. The Bishnumati also rises in the Shivapuri Hills, some west of the Bagmati's source. It flows south past the Nagarjun Hill,
Swayambhu Stupa and
Durbar Square in Kathmandu. As it passes the centre of Kathmandu, this tributary becomes heavily polluted and choked with trash. Flowing generally south although with many curves, the Bagmati reaches the edge of the Kathmandu valley and enters
Chobhar gorge near the
Dakshinkali temple complex. The Chobhar gorge cuts through the
Mahabharat range, also called the Lesser Himalaya. This range is the southern limit of the "middle hills" across Nepal, an important cultural boundary between distinctive Nepali and more Indian cultures and languages, as well as a major geological feature. The Bagmati also crosses the lower
Sivalik Hills before reaching the
Terai, then crosses into India at
Bairgania. It flows across the districts
Darbhanga,
Sitamarhi,
Sheohar,
Muzaffarpur and
Khagaria in Bihar. It meets
River Kamala at Jagmohra Village of
Samastipur. However, in past the river had a different course and used to drain directly into the Ganges. In
Swasthani Bratakatha of the
Skanda Purana, Bagmati's present northern tributary was regarded as main channel called Sāli river which was a tributary of Gandaki and it is obvious since Manohara river, the present day Sali river, is larger than Bagmati at their confluence. ==Pollution==