It is the largest tributary of River Ganga. The River Ghaghara is called Karnali or Manchu in upper reaches and has its source in the Himalayan glacier about 60 km south-west at Mansarovar at an elevation of 4800 m. After flowing for about 70 km in a southeasterly direction, the river enters Nepal. Ghaghara enters in India at Kotia Ghat near Royal Bardia National Park, Nepal Ganj, where it is known as the river Girwa for about 25km. The total catchment area of the Ghaghara River is about 127,000 sq. km, out of which 45% falls in India.The total length of the Ghaghra River up to its confluence with Ganga at Doriganj in Bihar is 1080 Km. Various tributaries are Saryu, Sarda, Rapti, Kwano, Little Gandak, Seti etc.

River Ghaghra

The geographical extent of the Ghaghra basin lies between 79°29' to 84°49’ east longitudes and 25°47' to 30°55' north latitudes in China, Nepal, Uttarakhand, Bihar, and Uttar Pradesh covering a total area of 1,30,935.10 sq.km including complete Rapti Basin and 1,04,861.92 sq.km excluding complete Rapti Basin. The portion of Ghaghra basin falling in Uttar Pradesh lies between east longitudes 79°29' to 84°49’ and north latitudes 25°47' to 30°31' covering an area of 31,503.00 sq.km in Uttar Pradesh. It is bounded by Gomti basin in the west and South, Rapti basin in East, West and South, Ganga and Gomti basin from South and Nepal from North. There are eight sub-basins defined in Ghaghra basin within Uttar Pradesh namely Chauka, draining 2850.68 sq.km (9.05%), Kuwano 5872.17 sq.km (18.64%), Little Gandak 3453.07 sq.km (10.96%), Lower Ghaghra 5778.65 sq.km (18.34%), Sarda 3126.67 sq.km (9.92%), Saryu 2560.02 sq.km (8.13%), Tehri 1530.17 sq.km (4.86 %) and Upper Ghaghra 6331.57 sq.km (20.1%).

There are 70 towns in Ghaghra Basin, out of which, 58 are Statutory Towns and 12 are Census Towns. There are five towns having a population between 1 to 10 lakhs viz. Bahraich, Basti, Faizabad, Gonda and Lakhimpur Kheri. The basin covers 21 districts (1 fully and 20 partial districts) and 157 blocks (81 fully and 76 partially) of Uttar Pradesh. The climate of Ghaghra basin is sub-tropical, monsoonal. Winters (October to February) are cool and dry with occasional fogs and light showers, summers (March to early June) are hot and dry, and the monsoon season (middle June to September) is warm and humid, with frequent heavy rainfall. The basin experiences very hot during summer season and very cold during the winter season except in Upper Tarai region and the hills of Nepal. The highest monthly mean maximum temperature is in the month of May (31.71°C) while the lowest monthly mean minimum temperature is in the month of January (10.9°C). 

Ghaghra basin- HO Network

The average annual rainfall in Ghaghra Basin is 1000.30 mm. It can be seen that rainfall in the Ghaghra Basin is dominated by monsoon rainfall (87.0% of total rainfall) in the months of June to September, with July and August being the wetter months in which most of the rainfall occurs (65% of monsoon rainfall and 56.13% of total rainfall). The humidity is the lowest during April and May. The maximum humidity is observed during the month of July & August and it goes up to 80% or more. The highest evaporation is in May (296 mm, 9.55 mm/day) while the lowest is in January (35 mm, 1.13 mm/day). The annual average pan evaporation rates for Ghaghra Basin is 4.62 mm/day. 

As per census 2011, the total population in Ghaghra Basin is 25,864,960. Out of which 2,083,813 (8.06 %) is urban and 23,781,147 (91.94%) is rural. Out of the total population 13,333,356 (51.55 %) are male and 12,531,604 (48.45%) are female. On average 42.6 % of the total population is living below the poverty line in the basin. In Ghaghra Basin, in addition to Girja and Saryu barrages, through the Saryu system, there are several lift schemes such as Saryu, Tanda, Kuwano, Ayodhya, Doharighat and Doharighat Feeder, Gola, and Dumariyaganj. Girija Barrage was constructed on Ghaghra River near Katarnia Ghat in Bahraich District of Uttar Pradesh.

Ghaghra Basin Map