Hyderabad: At a time when Telangana is grappling with alarmingly low reservoir levels, the Godavari and Krishna rivers are recording a sharp rise in faecal coliform (FC) levels, placing them among the country’s most contaminated major river stretches, after the Ganga and Yamuna.The latest data, for Aug, released by the Central Water Commission (CWC) under the Union ministry of Jal Shakti, show FC levels of 1,60,000 most probable number (MPN) per 100 ml in the Krishna at Suryapet and the Godavari at Mulugu and Nizamabad. The readings are 320 times the reference benchmark of 500 MPN/100 ml, highlighting the scale of faecal contamination in the two river systems.In June, TOI reported FC levels of around 9,200 MPN/100 ml in these rivers — already nearly 20 times the benchmark. Since then, the readings have surged to 1.6 lakh MPN/100 ml, marking an increase of more than 1,600%.Experts warn that the findings are particularly concerning because the Godavari and Krishna are important sources of water for Telangana, including for Hyderabad’s drinking water supply, which meets more than 90% of the city’s requirement. The high concentration of human and animal waste poses a risk of serious health problems.“Although water drawn from these rivers is treated before being supplied to households, inadequate treatment or contamination after treatment could expose consumers to waterborne diseases such as diarrhoea, typhoid and parasitic infections,” said MVSS Giridhar, professor at the Centre for Water Resources, JNTUH.El Niño compounds the problemKey contributors include untreated or inadequately treated sewage, leaking sewer lines, septic tanks, drains and runoff carrying human and animal waste. Below-normal rainfall this year, which experts attribute partly to the El Niño effect, has compounded the problem by reducing river flows and limiting the dilution of pollutants.The contamination is not confined to these three locations. Other monitoring points in Mulugu and Bhadradri Kothagudem, as well as the Musi tributary at Valigonda, nearly 60 km from Hyderabad, have also reported alarmingly high FC levels, far above prescribed benchmarks. At Bhadrachalam and Mancherial, FC levels of 92,000 MPN/100 ml were recorded — 184 times the benchmark.A study by the National Institute of Technology (NIT), Warangal, commissioned by the Union ministry in 2024 to prepare a condition assessment and management plan for the Krishna river basin, highlights the problem of untreated sewage discharge from towns and cities.“Most urban settlements along the Krishna release untreated sewage directly into the river. In parts of Suryapet, several houses lack even septic tanks, allowing human waste to flow into the river and worsen contamination,” said a professor at the Centre for Krishna River Basin Management and Studies, NIT Warangal.The NIT report also identifies pollution from pharmaceutical and synthetic chemical industries in the Telangana stretch of the Krishna basin, with implications for Nagarjuna Sagar, which supports irrigation and power generation. Activities such as bathing further add to the pressure on river water quality.Experts said below-normal rainfall may have further aggravated the problem. Unlike in years of heavy rainfall and floods, when increased flows can carry pollutants downstream, reduced river flows can allow contaminants to remain more concentrated.“Sewage discharged from residential settlements causes faecal pollutants to accumulate in riverbed sediments during summer. With the arrival of the monsoon, it usually disturbs these sediments, resuspends the contaminants, pushing up coliform readings at monitoring stations,” said B Venkateshwar Rao, an expert in water resources.BOX: Musi’s bacterial load adds to concernsThe results for the Musi at Valigonda in Yadadri Bhuvanagiri district raise further concerns about water quality, with dissolved oxygen and biochemical oxygen demand (BOD) levels deviating sharply from reference values.Dissolved oxygen was recorded at just 1.28 mg/l, against a reference value of at least 5 mg/l. BOD stood at 10.94 mg/l, more than three times the reference limit of 3 mg/l. Low dissolved oxygen can threaten aquatic organisms, while elevated BOD indicates that the decomposition of biodegradable organic matter is consuming oxygen in the water.“Weak monitoring and inadequate enforcement of pollution-control norms have allowed the problem to persist, with untreated or inadequately treated wastewater from residential areas and industrial units continuing to threaten river water quality,” said KM Lakshmana Rao, an expert in disaster management.Key recommendations for Krishna & MusiThe upper, middle and lower Krishna sub-basins face significant water-quality challenges arising from urban sewage, industrial effluents and agricultural runoff. Addressing these issues requires stricter enforcement of industrial wastewater discharge standards and adequate treatment of sewage before it enters rivers and other water bodies.Greater Hyderabad currently has 42 sewage treatment plants (STPs), with another 36 in the pipeline. However, despite thousands of high-rise buildings and gated communities, only around 600 are reported to have functional sewage treatment facilities, while the rest discharge wastewater into the Musi. Strengthening urban sewage treatment infrastructure and ensuring compliance by residential complexes are therefore crucial to reducing pollution.The Krishna basin also requires targeted interventions across its sub-basins. In the Upper Krishna sub-basin, monitoring groundwater levels, promoting water-efficient irrigation methods such as micro-irrigation, and improving soil health through green manure and riverbank buffer zones are important measures.In the middle Krishna sub-basin, integrated watershed management, soil conservation and agroforestry can help reduce agricultural runoff and erosion, while stricter controls on industrial pollution are essential. In the lower Krishna sub-basin, advanced wastewater treatment, effective management of industrial discharges and improved urban solid waste management are critical to protecting river-water quality.
