West Rapti River
Encyclopedia
Not to be confused with the East Rapti
in Chitwan Valley
some 100 miles (160.9 km) to the east, this Rapti drains Rapti Zone
in Mid-Western Region, Nepal
, then Awadh
and Purvanchal
regions of Uttar Pradesh
state, India
before joining the Ghaghara a major left bank tributary of the Ganges.
The West Rapti is notable for janajati ethnic groups – Kham Magar
among its highland sources and then Tharu in Inner Terai Deukhuri Valley, for its irrigation and hydroelectric potential, and for recurrent floods that led to its nickname "Gorakhpur's Sorrow".
Himalaya and the Mahabharat Range. A 3500 metres (11,482.9 ft) summit on this ridgeline marks a triple divide. North of the triple divide the Karnali and Gandaki basins are adjacent; south of it the Rapti and similar but smaller Babai River separate the two larger basins. After crossing into India, the Babai and Rapti separately join the Karnali's continuation called Ghaghara. The Ghaghara ultimately joins the Ganges, as does the Gandaki.
. The western tributary Māŗdī Kholā rises in northwestern Rolpa
and is joined by Lungrī Kholā draining northeastern Rolpa. The Mardi then crosses into Pyuthan
. It is joined by east-flowing Arun Kholā at Devithān where it enters a gorge through the Mahabharat Range.
Jhimruk Kholā -- east of the Mardi—mainly drains Pyuthan
. Below the upper highlands, an alluvial valley opens where Bahun
and Chhetri rice farmers irrigate paddy fields. At Cherneta, Pyuthan the Jhimruk approaches within 1.5 km of the Mardi and a 12 megawatt hydroelectric
plant exploits the Jhimruk being 200 meters higher.
Below Cherneta the Jhimruk loops east, becoming the border between Pyuthan and Arghakhanchi District
. Its valley narrows and steepens as it enters the Mahabharat Range. Partway through it joins the Mardi and the combined flow is then named the Rapti. The main river emerges from its gorge into the lower Siwalik Hills
and Dang District
. At Bhalubang Bazaar Nepal's east-west Mahendra Highway
bridges the river.
Below Bhalubang, Inner Terai Deukhuri Valley opens between the Dang and Dudhwa Ranges, both subranges of the Siwaliks. Valley, following the WNW trend of the Siwalik hills for 100 km. Although the land is fertile, before DDT came into use in the 1950s Deukhuri was so malaria
l that only the Tharu people who had genetic resistance could be confident of surviving the warmer months.
The river crosses from Dang into Banke District
. Approaching Nepalganj -- largest town in Nepal's western Terai
-- the Dudhwa Hills fall away and the river turns SE, crossing into Uttar Pradesh, India and flowing through districts Shravasti
, Basti, Sant Kabir Nagar
and Gorakhpur
, passing Gorakhpur
city at about 135 air miles (215 km) from Nepal.
Just west of the city it is joined by the smaller Rohini
rising further east in Nepal's Nawalparasi
and Rupandehi District
s, draining 794 sq km in Nepal then 1892 sq km in India. 60 km beyond Gorakhpur the Rapti joins the Ghaghara (Karnali) at Rajpur. About 120 km further on at Chhapra
, the Ghaghara reaches the Ganges.
s in premonsoon April to 451 cumecs at the peak of the monsoon in August. Maximum recorded flood was 7,390 cumecs on 10 September 1981. 100-year flood
flows are predicted at 10,100 cumecs. Over 700000 acres (283,280.2 ha) in Uttar Pradesh are at risk of floods every year.
Flood control projects under study include a dam at Jalkundi that would inundate 71000 acres (28,732.7 ha) of farmland in Deukhuri Valley. An alternative damsite is upstream at Naumure on the Pyuthan-Dang district border (27°53'N, 82°48'E). This would be an earthen dam 169 m high with 351 million cubic meters live storage capacity, storing excess monsoon flows for irrigation use during the following dry season and generating up to 207 megawatts. Impoundment would mainly be in gorges through the Mahabharat Range, inundating less farmland than the Jalkundi alternataive.
Plans are also underway for three irrigation sub-projects – Kapilvastu District
30500 hectares (75,367.1 acre) involving interbasin water transfer to the southeast, Deukhuri Valley 9500 hectares (23,475 acre), and Banke District
40000 hectares (98,842.1 acre).
East Rapti River
East Rapti River, a small river draining the Chitwan valley in Nepal, flowing west to join the Narayani River a short distance north of the Indian border....
in Chitwan Valley
Chitwan Valley
Chitwan Valley is an Inner Terai valley in the south of Nepal, encompassing the districts of Makwanpur, Chitwan and Nawalparasi. The valley is part of the Terai-Duar savanna and grasslands ecoregion of about 150 km length and 30–48 km width....
some 100 miles (160.9 km) to the east, this Rapti drains Rapti Zone
Rapti Zone
Rapti Anchal in the Mid-Western Development Region of Nepal. It is named after the West Rapti River which drains Rolpa, Pyuthan and part of Dang district. The remainder of Dang and part of Salyan are drained by the Babai. The remainder of Salyan and all of Rukum are drained by the Bheri.The...
in Mid-Western Region, Nepal
Mid-Western Region, Nepal
Mid-Western Region is one of Nepal's five development regions. Westward from the Central region surrounding Kathmandu are the Western, Mid-Western and finally Far-Western regions. Counter-intuitively, Mid-Western lies west of Western....
, then Awadh
Awadh
Awadh , also known in various British historical texts as Oudh or Oude derived from Ayodhya, is a region in the centre of the modern Indian state of Uttar Pradesh, which was before independence known as the United Provinces of Agra and Oudh...
and Purvanchal
Purvanchal
Purvanchal is a geographic region of north-central India, which comprises the eastern end of Uttar Pradesh state...
regions of Uttar Pradesh
Uttar Pradesh
Uttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...
state, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
before joining the Ghaghara a major left bank tributary of the Ganges.
The West Rapti is notable for janajati ethnic groups – Kham Magar
Kham Magar
Kham Magar and Northern Magar are descriptive terms invented by academic linguists and anthropologists for a nationality in the Middle Hills of mid-western Nepal inhabiting highlands extending through eastern Rukum and northern Salyan, Rolpa and Pyuthan Districts in Rapti Zone as well as adjacent...
among its highland sources and then Tharu in Inner Terai Deukhuri Valley, for its irrigation and hydroelectric potential, and for recurrent floods that led to its nickname "Gorakhpur's Sorrow".
Geography
The Rapti rises south of a prominent E-W ridgeline midway between the western DhaulagiriDhaulagiri
Dhaulagiri is Earth's seventh highest mountain at ; one of fourteen over eight thousand metres. Dhaulagiri was first climbed May 13, 1960 by a Swiss/Austrian expedition....
Himalaya and the Mahabharat Range. A 3500 metres (11,482.9 ft) summit on this ridgeline marks a triple divide. North of the triple divide the Karnali and Gandaki basins are adjacent; south of it the Rapti and similar but smaller Babai River separate the two larger basins. After crossing into India, the Babai and Rapti separately join the Karnali's continuation called Ghaghara. The Ghaghara ultimately joins the Ganges, as does the Gandaki.
Course
The Rapti's headwaters descend south from rugged highlands populated by Kham MagarKham Magar
Kham Magar and Northern Magar are descriptive terms invented by academic linguists and anthropologists for a nationality in the Middle Hills of mid-western Nepal inhabiting highlands extending through eastern Rukum and northern Salyan, Rolpa and Pyuthan Districts in Rapti Zone as well as adjacent...
. The western tributary Māŗdī Kholā rises in northwestern Rolpa
Rolpa District
Rolpa of 210,004. Livang is the district's administrative center.By Nepalese standards, Rolpa is an underdeveloped area plagued by low life expectancy and poverty . It was a major flashpoint in the 1996-2006 Civil War.Adjoining districts are Dang to the south, Pyuthan to the east, Salyan to the...
and is joined by Lungrī Kholā draining northeastern Rolpa. The Mardi then crosses into Pyuthan
Pyuthan District
Pyuthan District of 212,484. Pyuthan Khalanga is the district's administrative center.-Geography:Pyuthan borders Dang Deukhuri District to the southwest along the crest of the Mahabharat Range and extends about 50 km northeast through the Middle Hills to a 3,000+ meter ridge that is both...
. It is joined by east-flowing Arun Kholā at Devithān where it enters a gorge through the Mahabharat Range.
Jhimruk Kholā -- east of the Mardi—mainly drains Pyuthan
Pyuthan District
Pyuthan District of 212,484. Pyuthan Khalanga is the district's administrative center.-Geography:Pyuthan borders Dang Deukhuri District to the southwest along the crest of the Mahabharat Range and extends about 50 km northeast through the Middle Hills to a 3,000+ meter ridge that is both...
. Below the upper highlands, an alluvial valley opens where Bahun
Bahun
Bahun is a colloquial Nepali term for a member of the Pahari or "hill" Brahmin caste, who are traditionally educators, scholars and priests of Hinduism. They are also known as Barmu in Newari. By tradition—and by civil law until 1962—they represented the highest of the four Hindu...
and Chhetri rice farmers irrigate paddy fields. At Cherneta, Pyuthan the Jhimruk approaches within 1.5 km of the Mardi and a 12 megawatt hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
plant exploits the Jhimruk being 200 meters higher.
Below Cherneta the Jhimruk loops east, becoming the border between Pyuthan and Arghakhanchi District
Arghakhanchi District
Arghakhanchi is one of the districts of Lumbini Zone in Nepal's Western Development Region. The district headquarters are Sandhikharka.-Etymology:...
. Its valley narrows and steepens as it enters the Mahabharat Range. Partway through it joins the Mardi and the combined flow is then named the Rapti. The main river emerges from its gorge into the lower Siwalik Hills
Siwalik Hills
The Sivalik hills is a mountain range of the outer Himalayas also known as Manak Parbat in ancient times. Shivalik literally means 'tresses of Shiva’. This range is about long enclosing an area that starts almost from the Indus and ends close to the Brahmaputra, with a gap of about between the...
and Dang District
Dang district
Dang is a district in the state of Gujarat in India. The administrative headquarters of the district are located in Ahwa. The Dangs have an area of 1764 km² and a population of 186,729 ....
. At Bhalubang Bazaar Nepal's east-west Mahendra Highway
Mahendra Highway
Mahendra Highway also called East West Highway runs across the Terai region of Nepal, from Kankarbhitta in the east to Mahendranagar in the west, cutting across the entire width of the country. It is the longest highway in Nepal.-Overview:...
bridges the river.
Below Bhalubang, Inner Terai Deukhuri Valley opens between the Dang and Dudhwa Ranges, both subranges of the Siwaliks. Valley, following the WNW trend of the Siwalik hills for 100 km. Although the land is fertile, before DDT came into use in the 1950s Deukhuri was so malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
l that only the Tharu people who had genetic resistance could be confident of surviving the warmer months.
The river crosses from Dang into Banke District
Banke District
-Geography:Banke is bordered on the west by Bardiya district. Rapti zone's Salyan and Dang Deukhuri Districts border to the north and east. To the south lies Uttar Pradesh, India; specifically Shravasti and Bahraich districts of Awadh. East of Nepalganj the international border follows the...
. Approaching Nepalganj -- largest town in Nepal's western Terai
Terai
The Terai is a belt of marshy grasslands, savannas, and forests located south of the outer foothills of the Himalaya, the Siwalik Hills, and north of the Indo-Gangetic Plain of the Ganges, Brahmaputra and their tributaries. The Terai belongs to the Terai-Duar savanna and grasslands ecoregion...
-- the Dudhwa Hills fall away and the river turns SE, crossing into Uttar Pradesh, India and flowing through districts Shravasti
Shravasti District
Shravasti District is one of the districts of the Uttar Pradesh state of India and Bhinga town is district headquarter. Shravasti district is a part of Devipatan Division...
, Basti, Sant Kabir Nagar
Sant Kabir Nagar District
Sant Kabir Nagar district is one of the 72 districts of Uttar Pradesh state in northern India. Khalilabad town is the district headquarters. Sant Kabir Nagar district is a part of Basti Division. The district is bounded on the north by Siddharthnagar and Maharajganj districts, on the east by...
and Gorakhpur
Gorakhpur District
Gorakhpur district is a district of Uttar Pradesh state in India. Gorakhpur is the administrative headquarters of the district.-History:The district was ceded by the Nawab of Awadh to the British East India Company in 1801. With this cession, Gorakhpur was raised to the status of a district. The...
, passing Gorakhpur
Gorakhpur
Gorakhpur is a city in the eastern part of the state of Uttar Pradesh in India, near the border with Nepal. It is the administrative headquarters of Gorakhpur District and Gorakhpur Division. Gorakhpur is one of the proposed capitals of the Purvanchal state which is yet to be formed...
city at about 135 air miles (215 km) from Nepal.
Just west of the city it is joined by the smaller Rohini
Rohni River
The Rohni or Rohini River rises in the Chure or Siwalik Hills in Kapilvastu and Rupandehi Districts of Nepal's Lumbini Zone and flows south into Uttar Pradesh state, India...
rising further east in Nepal's Nawalparasi
Nawalparasi District
Nawalparasi District of 562,870. This district has given birth to many Nepal's top level people including late Prime Minister Tanka Prasad Acharya...
and Rupandehi District
Rupandehi District
-Village Development Committees :*Aama*Aanandaban*Amari*Amawa Marchawar*Amuwa Paschim*Asurena*Babhani*Bagaha*Bagauli*Bairghat*Balarampur*Bangai*Bangai Marchwar*Baragadewa*Barsauli*Basantapur*Betakuiya*Bhagawanpur*Bisunpura*Bodabar*Bogadi...
s, draining 794 sq km in Nepal then 1892 sq km in India. 60 km beyond Gorakhpur the Rapti joins the Ghaghara (Karnali) at Rajpur. About 120 km further on at Chhapra
Chhapra
Chhapra is a city and headquarters of Saran district in the state of Bihar, India. Chhapra is also written as Chapra. It is situated near the junction of the Ghaghara River and The Ganges River....
, the Ghaghara reaches the Ganges.
Development
The Rapti's flow has great seasonal variation because the river lacks sources in high elevation glaciers and snowfields to buffer pre-monsoon drought. Average monthly flows at Jalkundi (27°58'N, 82°14'E) in Deukhuri Valley vary from 17.6 cumecCumec
The cumec is a measure of flow rate. One cumec is shorthand for cubic metre per second; also cms or m3/s . Continuing the informal usage, the plural form cumecs is also common in speech....
s in premonsoon April to 451 cumecs at the peak of the monsoon in August. Maximum recorded flood was 7,390 cumecs on 10 September 1981. 100-year flood
100-year flood
A one-hundred-year flood is calculated to be the level of flood water expected to be equaled or exceeded every 100 years on average. The 100-year flood is more accurately referred to as the 1% annual exceedance probability flood, since it is a flood that has a 1% chance of being equaled or exceeded...
flows are predicted at 10,100 cumecs. Over 700000 acres (283,280.2 ha) in Uttar Pradesh are at risk of floods every year.
Flood control projects under study include a dam at Jalkundi that would inundate 71000 acres (28,732.7 ha) of farmland in Deukhuri Valley. An alternative damsite is upstream at Naumure on the Pyuthan-Dang district border (27°53'N, 82°48'E). This would be an earthen dam 169 m high with 351 million cubic meters live storage capacity, storing excess monsoon flows for irrigation use during the following dry season and generating up to 207 megawatts. Impoundment would mainly be in gorges through the Mahabharat Range, inundating less farmland than the Jalkundi alternataive.
Plans are also underway for three irrigation sub-projects – Kapilvastu District
Kapilvastu District
Kapilvastu district of 481,976.-Geography:The district situated at the height of 93 to 1491 meters from sea level. Geographically, the district can be divided into plain low lands of terai and low Chure hills.Kapilvastu is bounded by-...
30500 hectares (75,367.1 acre) involving interbasin water transfer to the southeast, Deukhuri Valley 9500 hectares (23,475 acre), and Banke District
Banke District
-Geography:Banke is bordered on the west by Bardiya district. Rapti zone's Salyan and Dang Deukhuri Districts border to the north and east. To the south lies Uttar Pradesh, India; specifically Shravasti and Bahraich districts of Awadh. East of Nepalganj the international border follows the...
40000 hectares (98,842.1 acre).