Ten metres of stubborn black, basalt is all that stands between Maharashtra and 1,000 mega watts of power, and the anxious engineers cannot wait to breach this final barrier. Two years of toil that has put technological wizardry to the ultimate test is about to climax in an explosion that will unleash critical energy which will meet the state's peak hour power demands.

The blast will usher in the last leg of the World Bank-aided, Rs 1,100 crore, phase 4 of the Koyna hydro-electric power generation project, scheduled to be completed by December 1998.

Engineers of the State Government's Irrigation Department and thousands of labourers, powered by sheer adrenalin, have been workinground-the-clock to complete the project located in Koynanagar, straddling Satara and Ratnagiri districts. Phase-4, actual work for which commenced in 1992, has been delayed by more than a year and engineers are determined to complete the work by the December deadline.

Using a technique called Lake Tapping for the first time in India, it is the first totally underground power project in Maharashtra. Its uniqueness also lies in the fact that it has used only indigenous technology on par with international standards.

Two holes -- with a diameter of 6.5 metres each -- will be drilled in the bed of the Shivajisagar lake, which is nothing but the catchment water of a dam built on the Koyna river way back in 1962. The lake water, which will empty into these two giant holes, will be fed into two tunnels embedded 80 metres below the lake's surface and which run over 4 km under the Sahyadri mountain range.

After roaring down these tunnels, the water will plunge down four tunnels (diameter 3.9 metres) at an angleof 58 degrees and on to the turbines of a power generation plant located 580 mt below. The entire project, comprising a labyrinth of 33 tunnels that run 17 km, depends on precision rock-blasting techniques that leave no margin for error.

``The highest precision and extreme caution will be maintained while blasting this 10 metre thick rock and making way for the water to start flowing. Several small holes running 2 km will be drilled in this patch and explosives will be filled in the pierced rock,'' Deepak Kandi, circle engineer and project head, says, detailing the most crucial part of the project to Minister of State for Irrigation and Urban Development Ravindra Mane who visited the site on Saturday.

The water inside the tunnels will be controlled and regulated by three gates and can be completely stopped for maintenance and repair work. In case of emergency stoppage, the water in the tunnel can be diverted into a surge well, 21 mt wide and 131 mt high. Moreover, the flow can be halted in just 50seconds, which will prevent structural damage.

After leaping down 580 metres at an angle of 58 degrees through four tunnels, the water will carry a momentum of 72 km per hour. Each turbine will generate 16 MW, which in turn, will be stepped up to 250 MW each using a group of 13 transformers.

The giant turbines will rotate only during peak demand -- between 6 pm and 10 pm -- and the 1,000 MW of power so generated will augment the State's power supply grid through the Maharashtra State Electricity Board's network. Engineers working on the project say this capacity will be achieved by the end of 1999.

``The project is a miracle. Once through, it will prove why Koyna is termed as the `fate-line' of industrial Maharashtra. The power generated here will definitely boost industries and reduce peak hour demand statewide,'' says Mane.Displaced families threaten stir