Despite repeated promises of cleaning up, the river's condition has been deteriorating by the day. However, the issue is not entirely of pollution—the flow of water in the Delhi stretch of the river is not adequate.

Most of the natural river water is retained by the three barrages along the river for irrigation, drinking water and industrial use. The rest that reaches Delhi can hardly survive the amount of sewage and filth that the city dumps into it, and the natural riverine ecosystem is killed. But this issue was simply overlooked all these years.

The Congress government oversaw most of the Yamuna Action Plan-II which revolved around "cosmetic" improvements. The plan involved installing expensive sewage treatment plants (STPs) and expanding urban sewerage to keep waste water away. But a 2012 critique of the YAP by Massachusetts Institute of Technology International Science and Technology Initiatives (MISTI) pointed out that a large number of cities and villages are not connected to sewerage infrastructure and therefore even the new STPs are unable to intercept all the waste. Also, STP capacity is inadequate to meet the waste from the rapidly increasing population and STPs have no reliable power supply, resulting in release of raw sewerage. And while industries are responsible for managing and treating their own waste, they often don't do so.

"No amount of effort will yield any results unless a minimum flow is maintained in the Yamuna. The government has failed to tackle the root cause. The big question is: where has all the money gone? Restoration of the river is integrally related to how water flow is brought to the city," says Manoj Misra of Yamuna Jiye Abhiyan. A lot of infrastructural changes have taken place, such as building of toilets to avoid open defecation, crematoriums and sewage treatment plants. "The toilets remain unused, STPs are running grossly under their capacity so the entire policy remains disconnected," adds Misra.

Himanshu Thakkar of South Asia Network of Rivers, Dams and People (SANDRP) says the performance of the government has been 'pathetic'. "The threats to the river have only increased in 15 years with more and more encroachment of the river floodplain and the ridge. The government has failed to implement rainwater harvesting or even manage the demand. The CM herself has accepted that they have failed in saving the river," he says.

The experience with air pollution has been slightly different. Delhi's air continues to be very highly polluted. The state ranked 30th this time among 35 states monitored by the Planning Commission as part of the Environment Performance Index (EPI), of which air quality is a significant indicator. Just by monitoring Delhi Pollution Control Committee's real-time ambient air quality data one can gather that Delhi is dangerously high on not just particulate matter (PM 10) and PM 2.5 levels but also newer pollutants like nitrous oxide (NOx), ozone, volatile organic compounds (VOCs) and carbon monoxide.

While Delhi is one of the few states that have started monitoring many parameters which has led people to recognize the impact of newer pollutants, it's far from monitoring 32 parameters, including persistent organic pollutants (POPs), that Europe monitors. Introduction of unleaded petrol (1998), reduction of sulphur content in diesel (2000), reduction of benzene content in fuels (2000) and introduction of compressed natural gas in 2001 were some of the policies that were implemented during the Congress tenure.

The CNG impact has long worn out. It has been replaced by a massive surge in diesel-run private vehicles for which the government doesn't seem to have any answers. Recently, the government planned to unveil its 'agenda for air pollution control' which aims to meet permissible air quality standards by 2017 through various control mechanisms. But impending elections probably stopped it from releasing it as many may see it as restrictive.

Despite the new fleet of buses and the Metro, public transport hasn't become easily accessible. "Most of our investment goes into making it comfortable for car owners who constitute just 14% of the population. The government hasn't worked on improving the reliability of the bus network, speed, feeder services and walkability in the city. It's difficult to deal with air pollution until there is an effort to make the city accessible," says Anumita Roy Chowdhury, executive director, Centre for Science and Environment. Absence of restraints on car usage and low parking charges are among the main reasons for Delhi's failure to deal with air quality, she adds.