PROVISION OF WATER SUPPLY TO THAR COALFIELDS

Name of Scheme: Construction of Canal Water Carrier with Capacity of 300 Cusecs (Makhi Farash Link Canal Project, Chotiari Phase-II)

Scope: Thar Coal Mining & Power Generation Projects has initial demand of 300 cusecs fresh canal water. In this regard, Irrigation & Power Department has prepared a project for supply of canal water from Nara Canal system. The project envisages construction of a water carrier.

The assured water supply for Thar coal power projects proposed by constructing open CC lined channel with gravity flow from Farash regulator Ex-Lower Nara Canal to Nabisar through an old water way of Dhoro escape. Further the contours are not favorable due to sandy dunes topography of Thar Desert upto 350 ft height, therefore the water will be delivered through pressure pipe line from Nabisar to Islamkot ultimately extended to Thar Coal Field block-II in this regard sufficient water available in Nara Canal system.

The Nara canal is an ex-river and the main branch of Indus River naturally off takes from Sukkur barrage on left bank and was commissioned in 1932. The design discharge of Nara Canal is13649 cusec but at present drawing upto 20,000 cusec and irrigating areas in Khairpur, Nawabshah, Sanghar, Mirpurkhas, Umerkot and Thar districts of Sindh, the whole system comprises of 8312 R.D’s or about 1162.3 canal miles in length. In between upper & lower Nara canal, Chotiari reservoir was constructed with storage capacity of 0.71 MAF (supplement supplies in Rabi).

The Nara Canal has three weirs, one each located at Jamrao, Makhi and Farash. Makhi weir is 48 km below Jamrao and 120 km above Farash weir. Jamrao canal (3400 cusecs) off-take at Jamrao head, Mithrao canal (2400 cusecs) and Khipro Canal(1400) cusecs off-take at Makhi weir, while Farash which is at Tail of lower Nara where a number of channel off-take including Dhoro escape. The canal water for Thar Coal Power Generation Units will be supplied through its Farash regulator (2300 cusecs).

Thar Coal Water Carrier :
Thar Coal water carrier is proposed to be constructed in two phases,

Ph-I. Construction of stone pitching of Re-aligned Nara Canal from RD 0 to 105, CC lining of Makhi Farash Link Canal from RD 105 to 305, followed by construction of 100 cusecs CC lined channel from Farash regulator to Nabisar through Dhoro eascape natural water way about 214 RD in length and further by providing two pumping pipe lines of 4ft dia each with suitable pumps and intermediate reservoirs from Nabisar to Vajihar about 31 mile in length with carrying capacity of 50 cusecs discharge each in order to support system with auxiliary arrangement. As the natural contour limits the gravity flow with very mild gradient, hence it is also proposed to provide velocity booster (Persian wheels) at appropriate intervals in CC lined channel.

The main reservoir at Nabisar pat, which is a historical depression lake area of Dhoro escape having surface area of about 1000 acres will be converted for retention further the silt free water will be pumped through proposed spiral steel pipe lines. There is also proposed to construct a metallic road along proposed CC lined channel, which will provide additional supporting strength to the embankment of CC channel in Dhoro Escape and bifurcate the natural water way and leaving sufficient water way to Dhoro ecology, In addition this will also provide communication link to the adjoining settlements and facilitate the Monitoring/Operational activities.