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 the tendering and construction of hydropower 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.

 

The guidelines may help in the preparation of a bankable detailed project report (DPR) during the survey and investigation (S&I) stage, preparation of comprehensive bid documents, and improvement in construction-stage geological activities, the CEA said.

   

Tunnels are essential components of hydropower infrastructure, but their construction is highly sensitive to subsurface geological conditions. In the Himalayas, ground conditions are often unpredictable, with problems such as sudden water leakage, folded rock layers and high levels of seismicity. These often result in significant time and cost overruns, which in turn trigger contractual disputes, variation claims and erosion of stakeholder confidence.

 

Due to the geotechnical hazards often encountered during tunnelling, 90 per cent of infrastructure and hydropower projects globally exceed their budgeted cost, and tunnelling projects, on average, exceed their expected costs by 50 per cent, it said.

 

The guidelines recommend using advanced remote-sensing techniques through satellites, aircraft and drones equipped with sensors such as 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 such as Seismic Refraction Tomography (SRT) should be carried out throughout the length of the diversion tunnel.

 

Based on conventional and advanced geological and geophysical technologies such as remote sensing, aerial electromagnetic surveys and directional drilling, a Geotechnical Baseline Report (GBR) can be made part of the tender documents to show anticipated rock mass quality, hydrogeological conditions, problematic geological zones and other relevant geotechnical properties, as per the guidelines.

 

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

 

In twin-tunnel projects, the guidelines require the construction of 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.