2020 order on floodplain zoning declaring Gomti ‘non-perennial river’ draws flak

Subject :Geography

Section: Rivers in news

Context:

A three-year-old government order (GO) issued on September 3, 2020, by the irrigation department of the Uttar Pradesh government declaring the Gomti as a “non-perennial river” has drawn flak from water experts and river rights activists.

Details:

The order states: As it’s a non-perennial river, e-flow (environmental flow) cannot be maintained throughout the year and no surplus water is available to augment the flow.
The order also declared a 50 metres area from both banks of the river as a no-construction zone.
On June 18, 2010, the Lucknow bench of the Allahabad High Court ordered the UP government to stop all construction activities within 100 metres of the banks of the river.

About Gomti river:

Gomti is a tributary of Ganga river and an alluvial river of the Ganga Plain.
It originates near Mainkot, from Gomat Taala lake also known as Fulhar Jheel in Madhotanda. This is located around 30 kilometres from Pilibhit town in UP.
The river flows through Sitapur, Lucknow, Barabanki, Sultanpur and Jaunpur before meeting the Ganga at Kaithi, Ghazipur district.
It empties into the Ganga near Saidpur. The 960-km-long river also supplies around 450 million litres per day of water to Lucknow.
As per a CPCB report from 2022, Gomti is the fifth most polluted river in the country.
Tributaries: Sai river, Sukheta river, Choha river and Andhra Choha river.

Pollution in Gomti river:

Recently, thousands of dead fish are found along the bank of the Gomti river.
The fish had died as dissolved oxygen level of the river water had dipped too low.
Officials of the pollution prevention board blame untreated muck for this situation.
The dissolved oxygen levels dipped to as low as one milligramme per litre (mg/l). A minimum level of four to six mg/l is considered essential to sustain aquatic life.
- Dissolved Oxygen is a measure of the amount of free oxygen available in river systems.
- The quality of water increases with an increase in DO levels.
Cause of pollution:
- Discharge of untreated sewage
- Discharge of industrial effluents and domestic wastes
- Encroachment of floodplains

Biological Oxygen Demand (BOD):

BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water. It is expressed in milligrams of oxygen per litre of water.
The higher value of BOD indicates low DO content of water.

Chemical Oxygen Demand (COD):

COD measures the amount of oxygen in parts per million required to oxidise organic (biodegradable and non-biodegradable) and oxidizable inorganic compounds in the water sample.

Presence of Solariella in Gomti river:

Monitoring by the state pollution control board reveals the water is unfit for consumption.
A marine species of molluscs — Solariella — was recently found in the river.
This is alarming, as Solariella is endemic to coastal waters that ordinarily have high levels of ph.
The presence of Solariella was revealed during the first-ever biomapping of the river done by the Geological Survey of India (gsi), Lucknow.
According to the gsi report, the invertebrate species, Solariella, may have been introduced in the river by birds like waders.
In other areas (Madhavpura, Isauli and Bashariaghat) they have found Hemicypris arorai — another organism that survives in highly alkaline water.
- The high ph levels of these areas were mainly attributed to the use of fertilisers in nearby fields.