Jharkhand Assembly is posing a classic case of collective amnesia.

A rainwater harvesting system, which was inaugurated seven years ago by then chief minister Madhu Koda, has slipped from everyone's memory like butter. While no one seems to have seen the plaque announcing the launch of the water conservation technique, the storage tank is slighted as a gaddha (hole) where garbage is dumped.

In 2008, the tank - measuring 12ft by 7ft - was built near the Assembly secretary's office in the main building. A pipe from the rooftop was linked to the tank to channel rainwater.

Since the building construction department raised the facility on the right side of the approach road to the 14-acre premises, it should have been in plain view of some 82 ministers and MLAs, and 700-odd employees entering the Assembly. And yet, today, the tank is caked with garden soil and collects waste instead of water.

The Telegraph contacted at least 15 government servants, including Assembly Speaker Dinesh Oraon, secretary Sushil Kumar Singh, deputy secretaries Sishir Kumar Jha (in-charge of building maintenance), Madhukar Bhardwaj and Mithilesh Mishra, as well as gardeners, but no one seemed to remember whether a single drop of rainwater was harvested at the facility that they "didn't know existed in the first place".

"You are the first to inform me about a rainwater harvesting system here. I was not aware of it," Speaker Oraon honestly accepted his ignorance.

Assembly secretary Singh drew a blank when asked about the water conservation technique.

So did Jha who had to ask his junior where the tank was. "I joined this division (building maintenance) only a few months ago. I was not aware of the system," he said, emphasising that his work was limited to coordinating with different departments such as building construction, water supply and energy, and sending requisitions for repair or renovation.

Another senior Assembly official was candid. " Aap kis gaddhey ki baat kar rahe hain? Kya yahan water harvesting system bhi tha? Madhu Koda kab inaugurate kiye they? Humko doubt hai ki yeh kabhi kaam mein aaya hoga (Are you talking about that hole? Was there a water harvesting system there? When did Koda launch the system? I doubt the facility ever functioned," he said.

Secretary Singh maintained that if the system had gone defunct, it was the responsibility of the building construction department to repair it.

Junior engineer (building construction) Sudhir Kumar, who is posted at the Assembly, expressed ignorance about when the project was launched, completed and how much investment went into it. "Are you talking of the abandoned tank, which is filled with sand and soil? I was posted here only two years ago. I don't know about it," he said.

Speaker Oraon, however, said he would summon officials concerned within a few days. "I promise to revive rainwater harvesting on the premises. I feel bad that we who make the law inadvertently did not follow conservation rules. After all, government buildings should boast the provision when Ranchi faces acute water problems," he added.

Chief minister Raghubar Das holds the building construction portfolio.