TRANSFORMATION OF THE RIVER THAMES
It is a surprise to know that The River Thames is considered one of the world's cleanest rivers running through the city. It is even more surprising that this status is reached in 60 years. The Thames still faces new and increasing threats from pollution, plastic and increasing population.
THE THAMES:
The Thames runs 229 miles from Kemble to Essex and bisects London city. It is experiencing pressure from the increasing population from the medieval period.
The river has become a repository for waste, with dumped rubbish, and leaking cesspits.
The final straw is referred to as the Great Sink when high levels of human and industrial waste in the river actually drove people out of London.
During Second World War, bombing across the city destroyed the sewage network of the city, allowing the entry of sewage into the river. It is heavily contaminated with heavy metals from roads and industries, creating a toxic aquatic environment.
DISSOLVED OXYGEN-
The amount of oxygen that is present in water is called dissolved oxygen(DO).
For the fish to survive, the DO should be 4-5miligrams per litre. The DO levels in the Thames were 0.5mg/l in the 1950s. That says the river didn't support the survival of fish. Hence The Thames is considered "biologically dead."
TURNING TIDES-
- With considerable effort from policymakers, the river's fate began to change.
- The privatization of water companies established the protective NATIONAL RIVERS AUTHORITY, in 1989 and the introduction of biotic monitoring.
- The turning point in the Thames' health was the installation of large oxygenators or bubblers, to increase DO levels.
- A self-powered "Thames Bubbler" in 1988, and a third vessel was launched in 1999. Together, they're responsible for maintaining oxygen at a level sufficient to support the growing fish population.
- Today around 125 species of fish are regularly recorded including salmon, sea horses etc.,
Although the recession in the 1990s saw the loss of many industries that had been pumping waste and heavy metals didn't significantly change the water pollution levels. Currently, a new 25km super sewer is being constructed in London to handle this increased load.
More investment is needed in new drainage infrastructure across the city to avoid damage from increasingly pollution, storm surges etc.,
THE THAMES vs THE GANGES
- The National Mission for Clean Ganga was implemented by the National Council for Rejuvenation, Protection and Management of River Ganga, established on 12th August 2011.
- The Ganges is the largest river stretching 2525km providing a livelihood for millions of people and the most polluted.
- The DO level in The Ganges is 8.9mg/l which is considered as healthy for aquatic life.
- The quality of the Ganges is improved since 2014.
DRAWBACKS
- Wastes from paper, sugar mills, and tanning industries are the major pollutants of Ganga.
- Illegal constructions and poor governance are also making NMCG lame.
- Around 3million sewage is being dumped into The Ganges.
- a Large amount of coliform bacteria is found in The Ganges, making it unfit for consumption and bathing.
- AdiGanga, a stretch of Ganga is being planned to be converted into the drainage.
Decades of planning and hard work, millions of pounds collected in the form of funds and taxes, made THE THAMES the cleanest river. The Ganges supporting good aquatic life are being planned to rejuvenate into the drainage.
