KARACHI: The Sindh irrigation department has initiated a feasibility study to explore an ancient river course in Thar as part of its longterm programme to end the desert`s dependence on unpredictable rainfall as the only source of its water needs, it emerged on Wednesday.

The report sent to the chief minister as the department`s input to the government efforts to end the nagging healthcare disaster in Thar said the study was meant for the exploration of groundwater along the old course of the historical Hakro River.

Sharing brief details of the study, the report said that Thar had been a hub of agricultural activity in ancient times because of the Hakro River, which later changed its course from Choolistan to the west.

`The evacuated channels are presumed to exist and buried by drifting sand. This buried river course must be in the form of large aquifer from which water could be extracted for utilisation,` said the report.

The report said the study entailed survey of the area for groundwater profiling and the old river course and preparation of different schemes. `The abandoned track may be fed by Nara Canal or Ghotki Feeder Canal for groundwater replenishment and rising,` it said.

Similarly, the report proposed various other projects with the objective to make Thar self-sufficient and said water constraints in Thar could be mitigated by rainwater harvesting and storages through construction of small dams.

The dams would provide surface storages and the stored water would percolate to raise the groundwater table. Shallow depth of underground water table would be feasible for usage by means of pumping, for drinl(ing as well as agricultural purpose, said the report.

Officials said the department had conducted various feasibility studies and submitted PC-Is to the competent authority for approval.

They said that conventional method of surface irrigation and consumption of excessive amount of water was unaffordable in water scarce area like Thar. Thus, non-conventional method of drip and sprinkler irrigation system had been proposed to be associated with construction of small dams. Stored water would be efficiently utilised in this way for the cultivation ofthe vast desert area,they said.

The report also proposed rehabilitation or upgradation of upper and lower Nara canal.

Nara canal was a natural river, which branched out of the Indus near Arore in ancient times. Its alignment ran along desert and further to some extent the course was given separate feeder channel from Sukkur Barrage for regulated supply of water, said the officials.

The Nara river track has natural meandering and kinks throughout its length and can carry a discharge of up to 14,000 cusecs.

The projects for upgradation by straightening, dragging and construction of four fall struc-tures are ongoing schemes, which will enhance its capacity to 20,000 cusecs. Similarly, Lower Nara canal system is being remodeled up to Farash regulator, which will improve supplies along Thar region.

The Chotiari reservoir with storage capacity of 0.7 million acre feet (MAF) is integrated to Nara system, which is rarely filled to maximum storage level and capacity, as present capacity of Nara canal hardly meets the irrigation requirement.

The officials said the project was being funded by the federal government and the World Bank loan. Upon completion, it would enable Nara canal to take flood supplies to Chotiari lake and facilitate storage of water during shortages, they said.

Likewise, the extension of Mithrao canal was yet another such scheme. Mithrao irrigates the boundary line areas along Thar. It had been proposed to remodel and line distributaries of Mithrao for water conservation to take adequate quantum of water till the gravity flows, they said.

They said that during summers surplus water was available in the Indus system which could be diverted to Thar. For this purpose, Rainee Canal was being constructed jointly by WAPDA and Guddu barrage, they said.

The canal would be operative for two months of a typical year and its water would be used for short periodfodder crops.Based on experience of this project more such canals would be proposed, said the ofhcials.