Ahmedabad: Impact of industrial development on the Sabarmati

The earliest cities all over the world have emerged along riverbanks and Ahmedabad is one such city, located along the river Sabarmati. It is the seventh largest city in the country and is the commercial capital of the Indian state of Gujarat. According to Census 2011, the city has a population of 5.57 million. The river Sabarmati divides the city into eastern and western parts. Most of the industries are located in the eastern part of the city whereas the western part is predominantly a residential and commercial area. The city falls in a dry and arid climatic zone, with mean temperature ranging from 41.3 C in summer to 26.3 C in winter. It receives an average rainfall of 782 mm, mostly in the monsoon months with an average of 35 rainy days in a year. The city has expanded from an area of 90 sq. km in 1971 to 464.16 sq. km in 2009 and is governed by the Ahmedabad Municipal Corporation (AMC). The industrial areas used to be outside the city limits but as the city expanded, the industrial estates on the eastern side got incorporated into the AMC limits in 1996.

The river Sabarmati originates in the Aravalli hills in the neighbouring state of Rajasthan, flows for a length of 371 km in the southwest direction, then joins the Gulf of Khambat and finally meets the Arabian Sea. It is non-peren-nial river. Presently, the river stretch in Ahmedabad city is being fed from the Narmada river water at Chiloda, due to the development of the river front on the Sabarmati. As the river flows through the city, there are a few storm water inlets which open up into the river. Downstream of the river, treated sewage and industrial effluents are discharged into the river from seven sewage treatment plants (STPs) and two pipelines carrying treated industrial effluents.

It is reported that urban areas have the most consistent and ubiquitous effects on degradation of the river water quality (Lewczuk et al., 2016), with industrial effluents and domestic sewage being the two major pollutants. The study of river water quality is assuming great importance in the current context in India due to increasing economic growth as well as rising urbanisation. With economic growth, the society’s demand for better living conditions is gaining importance and investments are being made in the infrastructure to treat pollution and improve environmental quality. As Ahmedabad is a major industrial centre (Chapter 4) as well as the main urban centre in Gujarat, this chapter examines the impact of the city on the river water quality¹.