Thirst quencher to cesspool: Despite spending crores, algae bloom resurfaces in Hussain Sagar

On January 10, a Twitter user Raj Bhagat shared a Google satellite image of the Hussain Sagar Lake. The image showed the presence of green color algae and black-colored sewage which created an inland delta as it enters the lake.

In another satellite image that he captured, shows hyacinth formation in Hussain Sagar due to agricultural, industrial, and domestic pollution of Fox Sagar, an upstream of Hussain Sagar and one of the oldest man-made reservoirs in India.

Hyacinth plants are considered a weed or nuisance to the water body as it enhances the evaporation rate of water and it affects the aquatic life in it.

The 450-year-old Hussain Sagar has been of great significance to the people of Hyderabad. It was the source of irrigation and drinking water for the people before the construction of Himayat Sagar and Osman Sagar.

"I remember swimming and catching fishes at Hussain Sagar. The water was flowing in a larger area then," well-known historian Sajjad Shahid fondly recalls.

Many factors were responsible for water quality deterioration in the lake. One of the major contributors is the industrial pollutants of the Patancheru, Kukatpally area. It pollutes the Kukatpally Nala in Begumpet which is a feeder river of the lake. Sewage also enters many of the feeder lakes which ultimately joins Hussain Sagar. Apart from these, the encroachment and construction activities happening besides the lake is also harming its pristine waters.

Understanding the problem of Hussain Sagar

Hussain Sagar lake has mainly four feeder nalas- Picket Nala, Banjara Nala, Kukatpally Nala, and Balkapur Nala. When the Picket Nala, Banjara Nala, and Balkapur Nala brought domestic sewage into the lake, the Kukatpally Nala discharged a mix of domestic sewage and industrial effluents.

The domestic sewage, industrial pollutants, and stormwater together increased the content of organic matter- nitrogen and phosphorus in the lake. This accumulation of nutrients in the water leads to eutrophication (water bodies getting enriched with minerals and nutrients) and as a result, to algae formation and growth of hyacinth.

Ganesh idol immersion

Every year thousands of Ganesh idols are immersed into Hussain Sagar which is a major cause of pollution.

On September 16, 2020, the Supreme Court of India allowed the Telangana government's request for symbolic immersion of Ganesha Idols in the Hussain Sagar in the city. The bench of Chief Justice of India NV Ramana and Justice Surya Kant heard the plea by Greater Hyderabad Municipal Commissioner, Lokesh Kumar seeking permission to immerse Ganesh idols in Hussain Sagar.

On September 9, the Telangana High Court had banned the immersion of PoP idols in Hussain Sagar. A Division Bench comprising acting Chief Justice M.S Ramchandra Rao and Justice T. Vinod Kumar had also ordered that immersion of PoP Ganesha idols should be allowed at only designated spots along the Necklace Road.

"People from far-off places are coming to watch it and the government is making a lot of money with tourism during that period that it doesn't want to ban it," says Madhulika Chaudhary, a lake conservationist in the city.

Projects implemented for the lake's restoration

1. Hussain Sagar and Catchment Improvement Programme (HCIP) 2008-13

The project implemented in 2008, before the formation of Telangana state, aimed at improving the quality of water was initiated at a cost of Rs 310 crore taken as a loan from Japan International Cooperation Agency (JICA) and Rs 60 crore was the state's (Andhra Pradesh) share. The deadline of the project was set for 2012 and later shifted to 2013 but even after the extension, the project was not completed.

Seven fountains were installed at the lake to improve the dissolved oxygen content of the lake and thereby improve the aquatic life in the water, besides adding on to the aesthetic beauty of the lake.

2. Holistic Transformation of Hussain Sagar Lake

In 2020, Hyderabad Metropolitan Development Authority (HMDA) had signed a Memorandum of Understanding (MoU) with WRI India (an NGO) and DESMI (a company in Denmark) to clean up Hussain Sagar Lake.

Pollution Data 2021

Biological Oxygen Demand (BOD)

Biological Oxygen Demand or BOD is the amount of oxygen required by microorganisms living in the water to decompose organic matter like sewage present in water. If BOD is more, the water body is more polluted. If BOD is less, it is less polluted.

Unpolluted rivers have a BOD below 1mg/lt while for moderately polluted water bodies; BOD varies between 2 to 8 mg/l. According to the Central Pollution Control Board (CPCB), the acceptable range of BOD is 30 mg/l for drinking water.

As per monthly data provided by the Telangana State Pollution Control Board (TPSCB), at all the nine different locations of the lake from where the samples were connected, the BOD value ranged between 12 mg/l to 26mg/l as of 8 December 2021.

Chemical Oxygen Demand (COD)

Chemical Oxygen Demand also tests the amount of oxygen required to decompose organic matter but here instead of microorganisms oxidizing, it is the oxygen demand of oxidizing agents added into water bodies.

CPCB sets 250 mg/lt as the permissible value of COD in drinking water.

The COD levels in Hussain Sagar stood at 48 mg/l to 80 mg/l as of 8 December 2021.

Total Dissolved Solids (TDS)

Total Dissolved Salts constitute all inorganic salts and some organic matter dissolved in water. Calcium, magnesium, sodium, and potassium are the main inorganic salts found in water bodies. They enter the water through natural phenomena and human activities like industrial pollution.

According to the World Health Organization (WHO), if the TDS level is less than 300 mg/lt, the water is excellent for drinking, good between 300 and 600 mg/lt, fair between 600 and 900 mg/lt, poor between 900 to 1200 mg/lt, and unfit for drinking if it exceeds 1200 mg/lt of TDS.

TDS at different locations in Hussain Sagar has been in the range of 695 mg/l to 813 mg/l in December 2021.

What's wrong with restoration measures?

"Sirf money is not enough," says Mahdulika. "Instead, you should love them, feel that they are much more than just water bodies, and realize that they are part of our family, culture, religion, civilization, etc," she adds.

Mahdulika narrates her own experience of waiting for over five days to get permission from the government to organize a cleaning drive in Hussain Sagar Lake. "Hussain Sagar is a political agenda for the government. With the data on crores of rupees spent, they just want to show that they are marinating it," she says.

Another important concern that she raises is of the non-functioning Sewage Treatment Plants (STPs) in the city. "Around 150 MLD of untreated sewage flows into Hussain Sagar every day," she says. "Out of the 33 STPs, 50% are not working. Why are they not working? Has the government ever reasoned it out," adds Madhulika.

Commenting on the government interventions in restoring Hussain Sagar, Sajjad says, "Too little, too late. It is not possible or increasingly difficult to rejuvenate the quality of the lake. Silt deposits in the lake are toxic."