Expression of Interest for Consultancy Services for the Lesotho to Botswana Water Transfer Conveyance System Technical Feasibility Study B. Overview of Water Transfer System: The LBWT Conveyance System is fully piped and will transport raw water from a weir located downstream of a Dam on the Makhaleng River in Lesotho, to a proposed outfall upstream of Nnywane Dam in Botswana over 688 km. Several major road, rail, and watercourse crossings were identified that will require special design considerations. There are nine off-takes proposed to augment towns identified along the conveyance route in addition to the augmentation to Botswana. Geotechnical Investigations: Founding conditions in the areas where the route traverses dolomites from Lichtenberg to the South African border with Botswana, and in areas that have been undermined in the Free State Goldfields, require consideration because of the risk of subsidence and seismicity associated with underground mining. Pumping requirements: Elevations vary from 1850 to 1125 masl. Steel pipes with diameters ranging from 2200 mm to 1100 mm will deliver design flows ranging from 8731 I/s to 2735 I/s, resulting in pipe velocities between 1.3 m/s and 2.9 m/s. The total dynamic head requirement at the discharge in Botswana requires a combination of nigh lift pump stations, booster pump stations, and break-pressure tanks. Hydropower potential: At Chainage 660,7 km, a 65 m residual head could generate up to 3.2 MW at peak flow, and at Chainage 668.5 km. a residual head of 118 m could generate 5 9 MW Pumped Storage Potential: The high ground west of the dam site could be used to construct an upper storage dam at an elevation of 2000 m. The full supply level at the dam site is 1637 m. This could provide a static head in the order of 400 m. The distance between the two dams is 7 km. The additional water could be transferred from the Upper dam via a tunnel to near Matelile, from where it can gravitate via a pipeline to the conveyance route. Tender Link : https://www.pressreader.com/ (The Midweek Sun)
We takes all possible care for accurate & authentic tender information, however Users are requested to refer Original source of Tender Notice / Tender Document published by Tender Issuing Agency before taking any call regarding this tender.
