NAINITAL: The water level of Naini lake in Nainital , which has dropped to zero, should have been 5-7 feet above the zero mark in “ideal conditions”, said experts. Data from 2010 to 2018 show that it was only in 2015 that the water level in the lake stood 4 feet and 8 inches above the zero mark.

The surface of the southern end of the lake, known as Tallitaal , has been marked as “zero”. The water levels and depth of the lake are measured using this mark as a base.

G L Sah, a former professor of geography in Kumaon University and author of “Nainital Samay ka Kaleidoscope”, a book about the lake, said, “We should not be happy that the water levels are better than last year. Under ideal conditions, it should have been between 5-7 feet above normal.”

In the past few years, the water levels at Naini lake had been hovering between 3 feet above zero the mark to 5 feet 6 inches below it. In 2010, the levels were 3 feet above normal. In year 2011, it was 1 feet 8 inches. In year 2012, the level went down to an inch below the zero mark and the next year, it was 2 feet 6.5 inches above the mark. In 2014, it was 1 feet 5 inches above the mark. In 2015, it rose to 4 feet 8 inches and drastically came down to 4 feet 7 inches below the mark in 2016. It was lower in 2017, with 5 feet 6 inches below the mark.

The data also showed that in the years that the water level reached the mark zero, the month in which it did so varied. For instance, in 1923, the water touched zero in June, as it did in 1980, 2002, 2004, 2006, 2010. In the years 2009, 2011, 2013, 2014 and 2018, the water level touched zero in May. For 2012, it was April. In the years 2016 and 2017, the water had touched zero extremely early, by February.

Ajay Singh Rawat, 68, a noted activist who filed petitions in the Uttarakhand high court and Supreme Court for the conservation of the lake, said, “The main problem is infringement of the catchment area, which is Sukhaataal. It recharges 40% of the lake and needs to be free from concretization.”

Vishal Singh, a senior research scholar and executive director of Centre for Ecology Development and Research (CEDAR) said, “The cumulative impact of unplanned development and environmental apathy are visible; the lake level has reached zero level despite decent episodes of rainfall during the past two months.”

Officials of the irrigation department said that the levels remain at zero or drop further if there was no rainfall to recharge the water body, which is considered life line of the town.

In December last year, rationing of water supply from the lake was started to conserve the lake. Supply was also cut down to 8 million liters per day from 14 million liters per day. Last year on May 23, the water levels had touched a record low, plunging 18 feet below normal.

The decision to curtail the supply came after a preliminary survey was conducted by experts from Indian Institute of Technology, Roorkee, National Institute of Hydrology and Indian Institute of Soil and Water Conservation, according to sources in the irrigation department, the agency responsible for maintaining the lake.