The Sanskrit name of this river is Vitasta. The river got this name from the incident regarding the origin of the river as explained in Nilamata Purana. Goddess Parvati was requested by sage Kasyapa to come to Kashmir for purification of the land from evil practices and impurities of Pisachas living there. Goddess Parvati then assumed the form of a river in the Nether World. Then Lord Shiva made a stroke with his spear near the abode of Nila (Verinag Spring). By that stroke of the spear, Goddess Parvati came out of the Nether World. Shiva himself named her as Vitasta. He had excavated with the spear a ditch measuring one Vitasti(a particular measure of length defined either as a long span between the extended thumb and little finger, or as the distance between the wrist and the tip of the fingers, and said to be about 9 inches), through which the river - gone to the Nether World - had come out, so she was given the name Vitasta by him. 
A passenger traversing the river precariously seated in a small suspended cradle Circa 1900
The river Jhelum is called Vitastā in the Rigveda and Hydaspes by the ancient Greeks. The Vitasta (Sanskrit: वितस्ता, fem., also, Vetastā) is mentioned as one of the major rivers by the holy scriptures of the Indo-Aryans — the Rigveda. It has been speculated that the Vitastā must have been one of the seven rivers (sapta-sindhu) mentioned so many times in the Rigveda. The name survives in the Kashmiri name for this river as Vyeth. According to the major religious work Srimad Bhagavatam, the Vitastā is one of the many transcendental rivers flowing through land of Bharata, or ancient India.
The river was regarded as a god by the ancient Greeks, as were most mountains and streams; the poet Nonnus in the Dionysiaca (section 26, line 350) makes the Hydaspes a titan-descended god, the son of the sea-god Thaumas and the cloud-goddess Elektra. He was the brother of Iris, the goddess of the rainbow, and half-brother to the Harpies, the snatching winds. Since the river is in a country foreign to the ancient Greeks, it is not clear whether they named the river after the god, or whether the god Hydaspes was named after the river. Alexander the Great and his army crossed the Jhelum in BC 326 at the Battle of the Hydaspes River where it is believed that he defeated the Indian king, Porus. According to Arrian (Anabasis, 29), he built a city "on the spot whence he started to cross the river Hydaspes", which he named Bukephala (or Bucephala[disambiguation needed]) to honour his famous horse Bukephalus or Bucephalus which was buried in Jalalpur Sharif. It is thought that ancient Bukephala was near the site of modern Jhelum City. According to a historian of Gujrat district, Mansoor Behzad Butt, Bukephalus was buried in Jalalpur Sharif, but the people of Mandi Bahauddin, a district close to Jehlum, believed that their tehsil Phalia was named after Bucephalus, Alexander's dead horse. They say that the name Phalia was the distortion of the word Bucephala. The waters of the Jhelum are allocated to Pakistan under the terms of the Indus Waters Treaty.India is working on a hydropower project on a tributary of Jhelum river to establish first-use rights on the river water over Pakistan as per the Indus waters Treaty.
Verinag is approximately 80 km from Srinagar, by road, at an elevation of 1,876 m. It is believed that the eponymous Verinag spring is the chief source of the river Jhelum. There is an octagonal base at the spring, surrounded by a covered passage.
The Verinag spring is one of the principle tourist attractions of Verinag. The spring, which was originally shaped in a circular form was given a change of shape during the reign of the Mughal Emperor Jahangir in 1620, when he gave orders to renovate the spring in the Mughal traditional shape of an octagon. Today, picturesque in its settings and surrounded by tall pine trees, the Verinag Spring is characterized by waters which are calm and sparklingly clear.
Water control structures are being built as a result of the Indus Basin Project, including the following:
Mangla Dam, completed in 1967, is one of the largest earthfill dams in the world, with a storage capacity of 5,900,000 acre feet (7.3 km3)
Rasul Barrage, constructed in 1967, has a maximum flow of 850,000 ft³/s (24,000 m³/s).
Trimmu Barrage, constructed in 1939 some 90 km from Mari Shah Sakhira town, at the confluence with the Chenab, has maximum discharge capacity of 645,000 ft³/s (18,000 m³/s).
Harahpur (Victoria Bridge) Constructed in 1933 Approximate 5 km from malakwal near Chak nizam Village. Its length is 1 km mainly used by Pakistan Railways but there is a passage for light vehicles, motorcycles, cycles and pedestrians at one side.