CEA issues norms to reduce cost overruns in hydropower projects nationwide

The new guidelines recommend advanced geological investigations, greater transparency in tendering and continuous monitoring to reduce delays, disputes and cost overruns in hydropower projects

The Central Electricity Authority (CEA) has issued new guidelines for tendering and construction of hydro power projects to minimise geological uncertainties, reduce time and cost overruns, cut contractual disputes, and boost investor confidence.

 

It recommends the use of advanced technologies, calls for increased transparency in tender documents, continuous geological monitoring during construction, stronger safety measures for workers and a higher budget for geological investigations.

 

According to the body, the guideline is likely to help in the planning and execution of hydroelectric projects. It includes preparation of a bankable detailed project report (DPR) during survey and investigation (S&I) stage, preparation of comprehensive bid documents, and improvement in construction stage geological activities.

 

Tunnels are essential components of hydropower infrastructure, but their construction is deeply sensitive to subsurface geological conditions.Due to unpredictable ground conditions in the Himalayas, tunnel construction often results in significant time and cost overruns, which in turn trigger contractual disputes, variation claims and erosion of stakeholder confidence.

 

Due to ground-related hazards – landslides, soil subsidence, and liquefaction – often encountered during tunneling, 90 per cent of infrastructure and hydro-power projects globally exceed their budgeted cost and tunneling projects on an average exceed their expected costs by 50 per cent, it mentioned. 

The guidelines recommend using advanced remote sensing techniques through satellites, aircrafts and drones using sensors like light detection and ranging (LiDAR) systems to carry out high resolution surface geological mapping and develop a 3D digital terrain model of the proposed tunnel alignment incorporating major geological features. They also say that geophysical surveys like Seismic Refraction Tomography (SRT) should be carried out throughout the length of the diversion tunnel.

 

Based on the conventional and advanced geological and geophysical technologies like remote sensing, aerial electromagnetic survey and directional drilling, a Geotechnical Baseline Report (GBR) can be made a part of tender documents which shows anticipated rockmass quality, hydrogeological conditions, problematic geological zones and other relevant geo-technical properties, as per the guidelines.

 

To handle weak and difficult geological conditions in tunnels, advanced safety and stabilization measures should be used. These include regular monitoring of already excavated tunnel sections using standard instruments to detect movement or instability early, controlled blasting methods in very hard or stressed rock zones to reduce the chance of rock bursts.

 

In twin-tunnel projects, guidelines require building a connecting tunnel so that workers have an emergency escape route in case of collapse, flooding, fire or gas leakage. It also recommends creating a digital twin to simulate geology and tunnel behaviour.