Is Fighting for Survival, Let's Help Rejuvenate & Restore Her
A brief Profile
Once a beautiful lake in a perimeter of over 8 kilometres, at geographical coordinates of 21°14′56″N 79°5′56″E, just about 17 kilometres northwards of the city of Nagpur. It is a natural lake with mythological importance, due to the MahaLakshmi Jagdamba Mata Temple that is one of the 51 shaktipeethas, as described in various Hindu scripture including Brahmanda Purana, Shakthi Peetha Stotram written by Adi Shankaracharya, Mahapithapurana, Rishi Markandeya composed the ‘Devi Saptashati’ and many others.
The lake used to be an ornithologist’s paradise with sightings of various beautiful birds like Ibises, Ducks, Geese & Gadwalls also birds of Prey like Common Kestrel, along with Warblers like Booted Warbler, Paddyfield Warbler with Chats & Thrushes like Black Redstart and not to forget Sparrows & Buntings like Black-headed Bunting, Common Rosefinch, Red-headed Bunting. The whole region used to be lush green with lots of water and a healthy bio-diversity around. But things started changing since 1974.
The KTPS Factor
In the year 1974, The Koradi Thermal Power Station (KTPS) came into existence and the power generation started. The power plant is one of the four major power plants in Vidarbha region, State of Maharashtra, India. It is one of the nine active power stations operated by Maharashtra State Power Generation Company Limited (Mahagenco), a subsidiary of Government of Maharashtra owned Maharashtra State Electricity Board (MSEB). The plant operates 8 units and has a total power generation capacity of 1700 MW. A proposed 440 kilovolt high power transmission line from Koradi to Bhusawal would join Nagpur with Mumbai. KTPS campus also contains training institute of MahaGenco for middle and senior level engineers, technicians and other staff. Since the day the KTPS has begun the production, Vidarbha region has never looked back in terms of energy requirements. It left the whole country behind, and became a power surplus region. But every development has it’s own cost. And in this case the cost was water.
Otherwise a small village or a suburban settlement of Koradi, became an organised township with the beginning of the KTPS plant. This called for nearby villages to move closer, a market got developed, off course a complete ecosystem of school, hospital, malls, colleges, multiplexes and therefore private colonies and so on developed all around the lake. Ample amount of water is a necessity for dwelling of any animal habitat including humans, and thus Koradi Lake served that purpose, what went wrong was the disposal of waste water. As we, human beings have made water as the de-facto waste transport media, the waste water (both industrial acidic effluent from the plant and the domestic sewage water from the township and colonies nearby) had to be disposed and unfortunately it was disposed back into the same lake.
Now, the irony is that the water for KTPS and THPS (Totaladoh Hydroelectric Power Station) power station presently comes from Koradi Lake only. Also Nagpur Municipal Corporation provides treated water from its sewerage treatment plant. Due to further expansion of 3X660 MW more water is required by the plant. Hence the major source of water is available in nearby area and is Koradi Lake. To supply water from reservoir to Koradi Thermal Power Plant supercritical flow is necessary. Hence water must be pollution free. No silt shall enter into the system.
The degradation of lake
However, reservoirs are losing their water quality due to addition of waste water and increase in typha type grass and are therefore seriously threatened in their performance. Without any mitigating measures the viability of many reservoirs in the worldwide is questionable, as the impacts and losses are not balanced by the profits. Reservoir sedimentation shortens the useful life of reservoirs. Approximately 1% of the storage volume of the world’s reservoir is lost annually due to sediment deposition. The storage capacity of reservoirs decreases day by day due to accumulation of sediment. The total withdraw of water depends upon the capacity of the reservoir which is also determined. Evaluation of siltation of Koradi Lake is to be done which is again necessary for the withdrawal of water.
What is causing more concern is that the polluted water of lake is seeping into ground-water levels of wells, hand-pumps and other resources, and their water too is getting polluted. The chemists of Pollution Control Board had examined the samples of water and certified it as highly polluted, with a caution not to use the water. Even the power generation plant administration was served a notice to this effect.
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) published a research paper vide e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 12, Issue 3 Ver. I (May. – Jun. 2015), PP 11-14, titled, “Evaluation of Siltation and Analysis of Water Samples for Koradi Lake” conducted by student, professors and research scholar from Nagpur university and EX- NEERI Scientist & Director, Enviro Techno Consults from Nagpur.
The study was conducted using various tools and meters like, pH was determined electrometrically using digital pH meter, electrical conductivity was measured by conductivity meter, dissolved oxygen is measured by DO meter, total dissolved solid was measured by using TDS meter and similarly turbidity is measured by Nepthalo turbidity meter. Alkalinity, chloride, TDS, calcium, magnesium, total hardness, nitrate and phosphate were determined by NEERI Manual.
The total surface area of the lake was calculated using GPS and Autocadd. The present total surface area and the present capacity of the reservoir is determined using Autocadd and GPS. The reduction in capacity of a reservoir is the amount of silt accumulated in the reservoir. The maximum depth of the lake was determined. The actual depth of the lake was measured with a iron disc and measuring tape at different location/points. The depth was measured nearly at 50-60 points in the entire lake. The required data was taken from irrigation department, Koradi. The present total capacity is calculated. The total amount of sedimentation in the lake is also determined.
Below is the water quality test report after the above mentioned study conducted in 2015;
Five samples taken from five different point at five different depth, as depicted in the table above.
The study concluded that, the wastewater from Koradi colony is directly discharged into the lake without pre-treatment. This has resulted in loss of dissolved oxygen in the lake. The Langelier index is found to be negative which indicates that water present in the lake is corrosive. Also the Ryznar index is more than 7.5 which also indicates that water is highly corrosive. The surface area of the lake in 1974 was 194 Ha.
But at present the surface area of water is found to be 121 Ha. i.e. 73 Ha of lake surface area is covered by weeds, grass and is totally silted. The grass generally found is typha grass. The present capacity of the lake is 4.84 Mm3 and the original capacity of the lake was 6.16 Mm3 i.e. lake has a total silt deposition of 1.33Mm3. Net average depth of the lake has reduced because the area to the west of the bridge on the Chhindwara road is completely silted as also along the shore line. The maximum depth was found near to pump house which is 4m i.e. the depth of the lake has reduced by 3m in last 40 years. The lake is today in eutrophic stage i.e. the lake has more growth of typha grass and algal growth. Occasionally an excessive algal bloom occurs and can ultimately result in fish killing due to respiration by algae and bottom living bacteria. If the similar condition continues for the longer period, the lake may soon become ecologically inactive. Measures must be taken to improve the water quality and reduce the amount of silt deposition. Also the methods must be implemented to remove the silt accumulated in the reservoir, to increase the capacity of the lake.
2. A yet another research was conducted in 2016, as published in IJSRD – International Journal for Scientific Research & Development| Vol. 4, Issue 02, 2016 | ISSN (online): 2321-0613, by the name Effect of Phytoremediation on Koradi Lake Water, conducted by Snehal Khobragade (M.Tech Scholar) and Mangesh Bhorkar (Assistant Professor) from Nagpur University.
The study observed that the sewage water from nearby colonies is directly discharged into the lake without any treatment. The runoff water from nearby fields is also joining the lake water which has Eutrified the lake due to the presence of fertilizers and pesticides. The cooling water from the nearby Thermal Power station is also discharged in the lake directly. The lake was also been used for idol immersion for many years now and the Nirmalya and idols of different materials are commonly seen floating and on the banks of lake water. All these have degraded to quality of lake water to a greater extent and even the depth of the lake is reduced due to siltation. An immediate attention is required to stop further degradation of lake as well as the cleaning and purification of the lake.
Following were some key readings of the study;
- Ph : The pH of raw lake water was found to be varying between 8.22 to 8.79. The raw water was alkaline in nature.
- Turbidity: The Lake water was highly turbid. The average turbidity was found to be 88.44 NTU for Raw water sample.
- Total Dissolved Solids: The total solids in raw water sample were more than 1200 mg/l.
- Hardness: Raw water sample from the lake was found to be very hard. The average readings showed that more than 750 mg/l hardness was found in raw sample.
Koradi Lake - Nagpur
This petition is now closed.
End date: May 02, 2020
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Signature goal: 10000
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