Upper Tamakoshi Hydropower Project (456 MW) — Supply, Delivery, Installation & Commissioning of Water Level Sensor and Early Warning System (EWS)

The Upper Tamakoshi Hydroelectric Project is Nepal's largest operating power plant, with an installed capacity of 456 MW and an average annual energy output of 2,281 GWh. Sited on the Tamakoshi River in Dolakha district, this peaking run-of-river scheme comprises a 22-metre-high concrete dam, twin 225-metre-long desanding basins, an 8.4 km headrace tunnel, and an underground powerhouse equipped with six Pelton turbines operating under a massive gross hydraulic head of 822 metres.

Because the project sits in a seismically active, high-altitude Himalayan region prone to extreme weather, a robust project performance monitoring system and a flood early warning system are critical — particularly for tracking upstream threats such as the Tsho Rolpa glacial lake. These specialised automated networks provide real-time reservoir-level and hydrological data that help optimise daily peak energy dispatch, trigger timely safety protocols to prevent catastrophic downstream infrastructure damage, and enhance community resilience along the river corridor.

Under this contract, IES Nepal undertook the supply, delivery, installation and commissioning of the water level sensing and Early Warning System for the project. The scope spans three radar water level sensors across the reservoir, forebay and Tamakoshi River; the data acquisition and visualisation software for flood-level monitoring; and a full EWS covering the headworks and powerhouse with six sirens, wireless repeaters, a project-specific SMS alert system and dedicated EWS software — followed by testing, commissioning, and ongoing operation and maintenance of the integrated system.