HYDERABAD: The Greater Hyderabad Municipal Corporation (GHMC) has decided to switch over to a more effective method of clearing pipe culverts on main roads that have been blocked by silt accumulated over the years, by boring horizontally.
The civic body spends about Rs 50 crore annually to desilt these culverts within the Greater Hyderabad limits, but since the traditional method of using buckets to remove the silt fails to fully clear the pipes, roads -- especially in low-lying areas -- are often waterlogged.
That is not the end of the matter -- the silt stuck in pipes over the years has left them unfit for water flowing through them. When it rains in the city, the roads turn into cesspools because the water flow does not pass through the culverts. For starters, the GHMC has decided to try Horizontal Boring Technique in the LB Nagar zone in the first phase.
Horizontal boring is a method that entails equipment being placed on the surface while maintaining a specific 30-degree angle so that the drilling head reaches the entrance point of the drains. Once in place, a cutter is installed from the side and moved horizontally inside the pipeline, cutting and clearing the choked and silted area. The GHMC’s decision has been a long time coming — the civic body lags behind when it comes to adopting modern technology. For instance, the GHMC still deployed the bucket cleaning technique to remove silt from choked storm water lines.
Earlier, two workers in LB Nagar died during a cleaning operation using this technique. However, on the other hand, the Hyderabad Metropolitan Water Supply and Sewerage Board (HMWS&SB) has been using a state-of-the-art robotic system to track and clean choked sewer lines instead of manual operations for the past few years.
In this connection, the GHMC has invited quotations from agencies for clearing, cleaning and removing of silt inside the pipe culverts on main roads with the horizontal boring method, as well as making arrangements for traffic diversions.
The method
Horizontal boring is a method that entails equipment being placed on the surface while maintaining a 30-degree angle so that the drilling head reaches the entrance point of the drains