River Godavari
The Godavari rises near Trimbak in Nasik, Maharashtra. The river is 1,465 km along and joins the Bay of Bengal in Andhra Pradesh. It has a catchment area of 31 mha. The mighty river contributes about 3000 tmc of water annually at 75% dependability. The maximum flood so far observed is about 35 lakh cusecs at Dowalaiswaram anicut. Flowing in our state it is fed by tributaries like Penganga, Pranahita, Sabari, Indravati, Manjeera and Manair. On account of the high concentration of population, industries, towns and cities in the basin, large quantities of domestic and industrial wastes are discharged into the river. Waste water from agriculture, animal care, domestic and industrial use reach the river by leaching, drainage and surface wash-off during the monsoon. The application of fertilisers in the Godavari basin is 49.34 kg/ha, which is more than twice the national average. The total BOD load is 998 tonnes, whereas the total consumption of pesticides in the basins in Andhra Pradesh, Madhya Pradesh and Maharashtra is 21,586 tonnes. Industry produces a total of 808 million cubic meters (mcum) of waste anually. About 90,600 kg, that is, around 17.94% of the BOD load is from industrial sources. In addition to BOD load, industry releases various toxic pollutants in the rivers. The organic pollution load contributed daily by the urban sector alone comes to 414 tonnes/day. Parameters to decide river quality
Water quality is measured in terms of parameters like Biochemical Oxygen
Demand (BOD), Dissolved Oxygen Demand (DO) and Total Coliform Count. BOD
is a measure of water pollution based on the organic material it contains.
The organic material provides food for aerobic bacteria, which require
oxygen to be able to bring about the bio-degradation of such pollutants.
The greater the volume of organic material and the greater the number
of bacteria, the greater will be the demand for oxygen. Thus, the BOD
value gives an indication of organic pollution levels in the water. If
BOD exceeds the available dissolved oxygen in the water, oxygen depletion
occurs, and aquatic organisms suffer. Fish kills are not uncommon under
such circumstances.