The topographical survey and mapping of the project shall be geared towards preparation of the engineering site plans and sections of the project area, according to a tender notice published on the company’s website on 14 February. Engineering site plans and sections shall be prepared in sufficient detail to establish a sound basis for planning, engineering and design of the project. To attain the above objectives, the contracted party will be required to conduct a control survey for establishment of control points, an engineering site plan survey and a river survey. The contracted work should be completed within 180 days (90 days for Gongri project and 90 days for Jerichhu pumped-storage project) from the date of issuance of the Letter of Award.
The projects are planned in the Drangmechhu river basin, the biggest river system in Bhutan. The Gongri storage project is located on the Gongri river, one of the basin’s two major rivers, on the boundary of the Trashigang and Mongar dzongkhags (districts), four km downstream of the confluence of the Gongri and Sherichhu rivers. The main project components including the diversion tunnel with the powerhouse located at around 900 m downstream of the planned dam. A pre-feasibility study of Gongri, which was carried out by Dagachhu Hydro Power Corporation, the former operator of the Dagachhu plant, and now majority owned by DGPC, anticipated an installed capacity of 740 MW, and assessed the project to be techno-economically viable mainly considering its geology and the potential for its integrated development as a pumped storage facility.
An original topographic survey was outsourced to National Land Commission, while geotechnical investigations was outsourced to M/s. Bhutan Core Drilling & Geotech Services and geological studies and mapping was outsourced to M/s Alpha Geotech & Company.
The Jerichhu pumped-storage facility, which would be the country’s first, is planned in Trashigang Dzongkhag on the river Jerichhu, which is the left bank tributary of Gongri. A reconnaissance study, which was conducted by the erstwhile DHPS in collaboration with Japan International Cooperation Agency (JICA), found the project to be technically viable. The open-loop pumped storage project, with a maximum output of 1800 MW, is designed with inflow connected to the upper reservoir and a tail race tunnel connected to the lower dam which would be part of the Gongri hydropower project.
Detailed specifications, scope of supply and terms and conditions of supply as well as qualification requirements are given in the bidding documents, which can be downloaded free from DGPC’s website (www.drukgreen.bt). For further information, contact: Darjay Wangdi, Head, Contracts Management and Procurement Division, Druk Green Power Corporation, PO Box No. 1351, Motithang, Thimphu, Bhutan: Tel.: +975-2-339875; E-mail: d.wangdi269@drukgreen.bt
