Rivers, Lakes, Dams & Water Resources: previous-year questions

Answer: (D) (I) and (III)

Only pairs I and III are right. Rihand Dam (Govind Ballabh Pant Sagar) is on the Rihand, a tributary of the Son, in Sonbhadra district of Uttar Pradesh, and Rana Pratap Sagar Dam is on the Chambal at Rawatbhata, Rajasthan. Massanjore (Canada) Dam on the Mayurakshi stands in Dumka district of Jharkhand, although it was built with Canadian aid in 1955 mainly to irrigate Birbhum and is operated by West Bengal, a favourite trap in WBCS papers. Hirakud, the world's longest earthen dam, is on the Mahanadi near Sambalpur in Odisha, not Chhattisgarh. Chambal project sequence: Gandhi Sagar (Madhya Pradesh), Rana Pratap Sagar, Jawahar Sagar and Kota Barrage (Rajasthan).

Answer: (B) Cauvery (Kaveri)

Both dams are on the Kaveri. Krishna Raja Sagar (KRS) Dam is in Mandya district near Mysuru, Karnataka, built between 1911 and 1931 under engineer M. Visvesvaraya, with the Brindavan Gardens below it; Mettur Dam (Stanley Reservoir) is in Salem district, Tamil Nadu, completed in 1934. The Kaveri rises at Talakaveri in the Brahmagiri hills of Kodagu, forms the Shivanasamudra falls and builds a fertile delta around Thanjavur before entering the Bay of Bengal. Dams on the other rivers: Krishna, Nagarjuna Sagar, Srisailam and Almatti; Mahanadi, Hirakud; Godavari, Jayakwadi and Polavaram. The name 'Krishna Raja' refers to the Mysore ruler Krishnaraja Wadiyar IV, not the river Krishna.

Answer: (A) Wular Lake

Wular Lake in Jammu & Kashmir, fed and drained by the Jhelum, is India's largest freshwater lake. Loktak in Manipur is the largest freshwater lake of the North-East and is known for its floating phumdis, while Dal and Naini are much smaller.

Answer: (D) Jhelum

The Jhelum rises at Verinag, flows north-west through the Kashmir Valley past Srinagar and through Wular Lake, then cuts a gorge into Pakistan. The Chenab, Ravi and Sutlej flow through Jammu, Himachal Pradesh and Punjab instead.

Answer: (A) Brahmaputra.

The Raka (Raga) Tsangpo is a tributary of the Yarlung Tsangpo, which is the name of the Brahmaputra in Tibet. It has no link with the Mahanadi, Ganga or Krishna systems.

Answer: (D) Tapi

The Tapi, like the Narmada, flows west through a rift valley (a fault trough between the Satpura and Ajanta ranges) and enters the Arabian Sea through an estuary. The Luni is an inland drainage river of the Thar, and the Chambal and Son are Ganga-system rivers draining the plateau without a rift.

Answer: (A) Andhra Pradesh.

Kolleru, one of India's largest freshwater lakes, lies between the Godavari and Krishna deltas in Andhra Pradesh and is a wildlife sanctuary. Tamil Nadu, Kerala and Karnataka have other lakes, such as Pulicat and Vembanad.

Answer: (A) Krishna

Nagarjuna Sagar Dam is built across the Krishna on the Telangana–Andhra Pradesh border. The Tungabhadra is a tributary that joins the Krishna upstream and has its own dam at Hosapete, while the Godavari and Cauvery are separate rivers.

Answer: (D) Gomti

Lucknow stands on the banks of the Gomti, a tributary of the Ganga. The Ganga flows past Kanpur and Varanasi, the Yamuna past Delhi and Agra, and the Saryu past Ayodhya.

Answer: (B) Tamil Nadu.

The Mettur Dam and hydroelectric project are on the Cauvery in Salem district, Tamil Nadu. Karnataka has upstream Cauvery works such as Krishnaraja Sagar, which makes it tempting.

Answer: (A) Hirakud dam

Hirakud Dam on the Mahanadi in Odisha, about 25.8 km long including its dykes, is the longest dam in India. Bhakra is among the highest gravity dams, which makes it tempting, but it is far shorter.

Answer: (B) Rajasthan.

Didwana is an inland salt lake in Nagaur district of Rajasthan, like Sambhar, Pachpadra and Lunkaransar. Punjab and Odisha have no such lake, and Odisha's Chilika is a coastal lagoon.

Answer: (C) Sutlej river.

The Koldam hydroelectric project is built on the Sutlej in Bilaspur district, Himachal Pradesh, upstream of the Bhakra reservoir. The Beas has the Pandoh and Pong dams, and the Gandak and Bagmati flow through Nepal and Bihar.

Answer: (A) Mahi

The Mahi rises in Madhya Pradesh south of the Tropic, flows north into Rajasthan across it, then turns south-west through Gujarat and crosses it again before reaching the Gulf of Khambhat. The Narmada flows entirely south of the Tropic, and the Chambal and Mahananda cross it at most once.

Answer: (A) Chilika Lake

Chilika Lake in Odisha is India's largest brackish-water lagoon and a Ramsar site known for Irrawaddy dolphins. Pulicat is the second largest, Vembanad is Kerala's longest lake, and Loktak is a freshwater lake.

Answer: (A) Tapi

The Tapi flows west through a rift valley into the Arabian Sea and ends in an estuary, not a delta. The Cauvery, Godavari and Krishna flow east across a gentle slope into the Bay of Bengal and build large deltas.

Answer: (B) Saravathi river

Jog Falls (Gersoppa), about 253 m high, are on the Sharavati river in Shivamogga district, Karnataka. The Cauvery has Shivanasamudra Falls, which makes it tempting, and the Tapi and Bhima have no such falls.

Answer: (A) Ram Ganga Multipurpose Project — Madhya Pradesh

The Ramganga multipurpose project (Kalagarh dam) is in Uttarakhand, formerly Uttar Pradesh, not Madhya Pradesh, so pair (A) is incorrect. Shivanasamudra is in Karnataka, Hirakud in Odisha, and Nagarjuna Sagar on the Andhra Pradesh–Telangana border, so the other pairs are correct.

Answer: (B) Amarkantak hills

The Son rises near Amarkantak in Madhya Pradesh, close to the source of the Narmada, and flows north-east to join the Ganga near Patna. Amarkantak is part of the wider Maikal range, but the Amarkantak hills name the exact source; the Kaimur hills only flank the Son valley and the Rajmahal hills lie in Jharkhand.

Answer: (C) Wells and tube-wells

Answer as of 2022 — this may have changed since.

Wells and tube-wells (groundwater) are the largest source of irrigation in India, accounting for well over half of the net irrigated area, with Punjab, Haryana, Uttar Pradesh and Gujarat relying heavily on tube-wells. Canals come second and are most important in the plains of the north and in river deltas, which makes (A) the tempting option. Tanks are a traditional source mainly in the hard-rock areas of peninsular India such as Tamil Nadu, Telangana and Karnataka. River-lift irrigation serves only small areas.