Residents of Clyde and the surrounding district are being warned they might hear loud explosions during the day as part of work to upgrade Transpower transmission lines near the town.
The work, in Fruitgrowers Rd, involved a new technique for installing fittings, which required explosives to be used, project manager Mark McKeogh, of Electrix Ltd, said in a letter to landowners in the Clyde area.
Noise levels would be ''significant'' from the work near Clyde, which began yesterday, and there would be a blasts from a warning siren before explosives were detonated.
Transpower corporate communications manager Rebecca Wilson said, as a result of the work, the capacity of the lines between Roxburgh and Clyde would double, but the size of the towers would not.
Extra capacity would be gained by changing conductors on the lines from ''simplex'' to ''duplex'' conductors.
The work is a part of a Transpower project, known as the Clutha to Upper Waitaki Lines Project, to upgrade lines between Roxburgh and the upper Waitaki.
Two sections of the work, between Clyde and Roxburgh and between Aviemore and Livingstone, were under way, and other work was on hold until a review next year.
The two parts of the project were designed to provide better power supply security to consumers in Southland.
Future work would aim to transfer power northwards.
The total cost of the project was about $197 million. However, as only two of the five sub-projects were going ahead, the total cost was closer to between $40 million and $50 million.
Completion of the total project depended on the review next year but if other sections were to go ahead, Transpower expected the project to be completed by about 2018.
The letter to landowners explained the new technique for installing fittings would use ''implosive jointing'', which would connect lengths of conductors.
If people had concerns or questions about the work, they could contact Electrix Ltd.
The work near Clyde was expected to take about three weeks.
