River under threat

River Musi River, a seasonal river flowing eastwards, is one of the major tributaries of the Krishna River. It originates in the Ananthagiri Hills of Rangareddy district of Andhra Pradesh and joins River Krishna at Wadapally village of Miryalguda taluk of Nalgonda district. The length of the river is approximately 240 Km. This river flows through Rangareddy, Hyderabad, and Nalgonda districts. It has three tributaries, viz., Easa, Aleru and Paleru. While Easa is on the upstream of Hyderabad, the Aleru and Paleru rivers will join the river Musi in the down stream of the city.

It has a drainage area of 11,017 sq.Kms. Estimatedly, more than 110 million cubic metres of waste water is joining river Musi annually (1989-90). Total annual run-off in the river is 1410 MCM, with an average rate of flow of 45 cumecs. The river Musi originates about 70 Km upstream from Hyderabad city. There is extensive deforestation in the hills, where it originates. Water flow is entirely dependent on the South-West monsoon. The annual rainfall period is between 20 to 90 days in a year. No studies have been done on the sedimentation, and/or soil erossion.

About thirty anicuts have been constructed across River Musi. These anicuts supply water to over forty villages. This enabled paddy cultivation twice a year, viz. Kharif and Rabi. The utilization pattern of these anicuts across River Musi, contrary to general trend, is 100 per cent more than what was originally planned. This could be a unique case in the history of Indian irrigation systems.

Being a seasonal river, waters in Musi were channelised into reservoirs and canals at var¬ious places as additional storage for the harder times, and/or second crop. Almost every village has this link to its tanks through canals.

Pollution
Presently, the river flow is majorly sustained by the sewage of the city, and the industrial effluents. In the last fifty years, the water quality in Musi has undergone tremendous changes owing to Musi becoming the ultimate destination for all waste waters of Hyderabad, domestic, industrial and other purposes. Estimated¬ly, total quantity of waste water generated and released into Musi River is about 200 million gallons a Day (MGD).

With such a volume of daily inflow, a seasonal river became a perennial sewage channel. Also, the storm water drains carrying particulate matter drain into the river. This water contains often the pollutants of automobile pollution, since the rainwater in the entire area of the Hyderabad and Secunderabad is drained into the river. The area under Municipal Corporation limits is 172.6 sq.km. If urban agglomeration is added to it, the area occupied by the twin cities of Hyderabad and Secunderabad would be 727 sq.km. at present.

Low Cost Solutions
Conventional sewage treatment is expensive. Freshwater polluted by metals and industrial or agricultural chemicals re¬quires expensive, technologically advanced treatment. In the United States, government had provided $57 billion since 1972 - as much as 55-75 percent of construction costs, depending on the type of sewage treatment plants. The United Nations has estimated that construction costs for treatment plants and submarine outfalls for the 539 Mediterranean coastal towns with populations greater than 10,000 would amount to more than $5 billion.

Preventing pollutants from entering groundwater or surface waters can reduce treatment costs and downstream damage. Some existing, small-scale measures can also salvage nutri¬ents for use in raising food and creating habitat for wildlife. As an alternative to conventional sewage treatment, Arcata, California, a small coastal town of 15,000, has transformed a local garbage dump into 63 hectares of wetlands that serve as a simple, low-cost waste treatment plant. Sewage is collected in sewers, held in ponds where solids settle out, then released into marshes, where it is filtered and cleansed by natural processes. Some of the treated water irrigates other wetlands; the rest is pumped into the bay, where oyster beds thrive.

It appears that this approach requires more land than conventional sewage treatment plants. However, its cost-effectiveness depends on whether the land would produce greater value from the alternative use, such as agriculture or real estate development or road construction. One Swedish study concluded that the benefits of sewage treatment are greater than the costs of lost agricultural production on the same land.

In other areas of the world, partially treated sewage is used to raise fish. For example, a small fraction of the sewage generated by the 7 million inhabi¬tants of Lima, Peru, is directed into holding ponds, where solids settle out and bacteria decompose many of the wastes.

After 20-30 days, the water is clean enough to irrigate grain crops for cattle and to raise fish. A 1985 study for the World Bank described similar aquaculture operations relying on human excreta in Bangladesh, China, the Federal Republic of Germany, Hungary, India, Indonesia, Israel, Malaysia, Taiwan, Thailand, and Vietnam.

The largest single waste-fed aquaculture system in the world is the Calcutta sewage system, where water and sewage are fed into two lakes covering an estimated 2,500 hectares.

After an initial bloom of algae, fish-principally carp and tilapia are introduced, and additional sewage is fed into the lakes once each month. The system supplies about 7,000 metric tons of fish annually to the Calcutta market, or 2.8 metric tons per hectare per year.

Several measures can virtually eliminate human health concerns about fish from sewage-fed fish ponds, such as detaining sewage in stabilization ponds for at least 20 days before introducing it into fish ponds or transferring fish and shellfish to clean water before harvesting.

By: Donthu Narasimha Reddy