ALLOWING THE "FLOOD BLIND" ETPS TO PROCEED : WHAT WILL BE THE CONSEQUENCE? WHAT IS THE WAY FORWARD?

 Shanthala Ramesh

This Paper was submitted to the District Environmental Engineer at the Public Hearing conducted at Ernavur for the ETPS Expansion Project on 20 December 2024 

Abstract: 

Ennore Thermal Power Station (ETPS) Expansion Project is haunting the Flood Challenged citizens of Chennai. It is being planned at a site that is low lying and flood prone. The site was repeatedly inundated in 2005 and 2023. It was one of the most affected by the 2023 December Oil Spill from CPCL. However, the EIA Report has not bothered to study and understand about the flood threats to the site. Instead it has doctored the data relating to site’s distance from the nearby Kosasthalaiyar River to get the mandatory Environmental Clearance. The CRZ Map for the Area shows the Project’s Ash Ponds located with in the Flood Hazard Line. Filling up the site to increase its altitude in order to become inundation free is put forward as the solution. However, if the site’s altitude is increased, it would cause serious stress to the surface water flow of the region as the site is located in a hydrological bottleneck where a river meets two canals and a tidal backwater. Increasing the altitude of the site would cause a severe back flow of the north bound streams making them to flood the Manali Industrial Area and all the areas drained by the North Buckingham Canal namely Madhavaram, Perambur Peravallur, Ambattur, Thiru Vi Ka Nagar and Vyasarpadi . Additionally, Its ash ponds have obstructed and destroyed one of the important flood drains of Kosasthalaiyar namely Tulasi Nagar-Chittar Canal and the Old Nappalayam Canal making the areas drained by them highly flood prone. These ash ponds have been constructed on  fertile riverine alluvial plain and today the fertile lands have been made impervious. As the EIA Report has remained silent on all these issues and has blatantly lied about some of the very important factors like the project’s closeness to the river, the Report has to be set aside. As the Ash Ponds are located within the Flood Hazard Lines, they should be closed permanently. Old Nappalayam canal’s destroyed stretch should be resurrected ecologically. A comprehensive Flood Hazard Study for the entire North Chennai  region should be undertaken, and the project’s feasibility should be evaluated based on that flood hazard study.

Introduction:

Ennore Thermal Power Station (ETPS) was shut down after a 47 year long operation on 31.03.2017. For the first 30 years, it was discharging its ash slurry into the sea without any ecological impact study or guilt. It did not care about the opposition from the fishers. In 2000, pressure from the Judiciary forced it to construct an Ash Pond (Ref-1). Instead of the sea, it now chose a 294 Acre low lying riverine alluvial flood plain (erstwhile paddy fields and fish farms) (Ref-2) located within the High Flood Line or Flood Hazard Line. With no one to question, it pumped all its ash slurry into this fragile landmass  for the next 17 years. All along this time, its dykes obstructed and deflected the ever recurring floods of the life giving Kosasthalaiyar Riiver; additionally, they choked and destroyed the Tulasi Nagar and Old Nappalayam Drainage Channel (Ref-3) (Fig-1) flowing into the River completely thus causing  recurrent floods at Nappalayam and Tulasi Nagar. Apart from being the precursor of floods, the ash ponds made the land impervious. In the event of a breach today, these ponds have the capacity to flood the Ennore Creek with 2 Lakh Tons of Ash they hold (Ref-4). 

Fig-1

In the year 2008, as the days of shutting down the old plant were nearing, the southern one third portion of the the 237 acre site so far occupied by the Pattarai Lake, (Ref-5) (Fig-2) was demarcated for building the  new "Expansion" thermal power plant.  Since then, for the past 16 years the Project has had problems with its engineering contractors, Regulators, Judiciary and the Public for various reasons (Ref-6).  Sadly, these problems were not related to the lake and that the lake has now vanished (Ref-7). (Fig-3) However, on 4 December 2023, the floods induced by Cyclone Michaung, did not fail to inundate this reclaimed land. 

Fig-2

Fig-3

 It is in this backdrop, a Rapid EIA with no new baseline environmental data and marked as the Final EIA dated July 2019, has been allowed by the Regulators and the Judiciary to legitimately boast as a "Document of Truth" and to remain as the most important document of this Second Public Hearing. 

It is time to explore and understand the legitimacy draped on this EIA by the authorities scientifically.

A Land Below the Sea Level and a gross scientific Negligence

ETPS is located in a very low lying land. The EIA states that the altitude of this 237 acre land (hereafter "Main Land") varies between 0 m (Above Mean Sea Level) to 20 m (AMSL) (Ref-8). 

The EIA only talks about the altitudes of the "Main Land"; it fails to give the altitudes of the larger 294 acre "Ash Ponds" (Ref-9). 

The Source of the altitude of the Main Land is SRTM" (meaning - NASA's Shuttle Mission Topography Mission ). There is a catch here. The EIA does not state the resolution of SRTM. It does not state whether it had used the high resolution 30m DEM (Digital Elevation Model) or the low resolution 90m DEM to generate the Contour Lines.

Using a 30m SRTM DEM in Quantum Geographical Information System 3.34 (hereafter QGIS 3.34) gives us the contour lines ranging from -3.095m(AMSL) to +21.905m(AMSL) for the whole Main Land (237 acres). For the Southern Main Land (Expansion TPP Site - 84 Acres) the altitude ranges between -3.095meters AMSL to +6.905meters AMSL (Ref-10). (Fig-4)

Fig-4

The altitude in the Primary Ash Pond (252 Acres) is between -3.095 meters AMSL to -0.095 meters AMSL. The 42 Acre Secondary Ash Pond lies between -3.095 meters AMSL and -0.095 meters AMSL. So, both the Ash Ponds are located below Sea Level. (Fig-4)

While the EIA states that the Main Land is actually a "low lying Land", its figures are under represented. This under representation may be due to them using a low resolution SRTM 90m DEM instead of the 30m DEM we have used. They were negligent in not mentioning the resolution of the DEM but chose to mention just the name of the DEM provider namely SRTM.

The Map titled “Coastal Zone Management Plan - Tamil Nadu Map 2018 - Sheet No: D 44 08/NW” by  the National Centre for Sustainable Coastal management (NCSCM) 2017-18 prepared for the Department of Environment, GoTN (Ref-11)  (Fig-5) confirms the above finding about the extreme low altitudes at which the Ash Ponds are located. This Map visually depicts the entire Ash Pond Area with in the "Flood Hazard Line"

Fig-5

In June 2021, Asian Development Bank (ADB) had published its “Initial Environmental Examination” Report titled “ INDIA: Proposed Integrated Urban Flood Management for the Chennai-Kosasthalaiyar Basin Project”. In its Executive Summary talks about the Flood vulnerability of Ernavur and Kargil Nagar (Ref-12): 

“ In the project area (Kosasthalaiyar drainage basin), the eastern portion of the north Buckingham-Canal watershed (See Fig-6) is lower than the canal bed level, hence an existing pumping station equipped with 2 nos. of 10 HP pumps having a capacity of 2833 LPM each and 3m diameter sump was constructed near Kargil Nagar to pump the rainwater into Buckingham Canal during floods. Based on the detailed analysis, it was found that existing pumps are very old and does not have sufficient capacity to pump the rainwater during floods. Hence, an additional pumping station comprising of 3no’s higher capacity pumps are proposed in Kargil Nagar. Based on the detailed analysis, a new storm water pumping station has been proposed at Ernavoor to avoid flood inundation.”

Fig-6 

Why would the EIA Expert Lie openly about the nearness of the Site to the River?

The EIA states that the proposed site is >500m away from sea and Korattaliyar (Kosasthalaiyar) River is around 575 m from project site (Ref-13). 

The first statement is correct. The site is located 776 to 859 meters away from the Sea. 

However, the second statement is a BLATANT LIE.  THE ACTUAL DISTANCE BETWEEN THE MAIN LAND AND KOSASTHALAIYAR RIVER IS BETWEEN 62 METERS TO 117 METERS.

THE ASH PONDS ARE LOCATED AT 86 TO 215 METERS FROM THE RIVER AND THE CRZ1 ZONE. (Fig-7)

Fig-7

A Low Lying Site located within 62-117 meters from the River that floods regularly : Need to know the importance of the Sadayankuppam-Ernavur Tri-Junction 

The EIA neither talks about the effect of the devastating 2015 flood on the region nor about the Oil Spill from Chennai Petroleum Corporation Ltd (CPCL) that entered the ETPS Site premises on 4 December 2023 during the flood that followed Cyclone Michaung.

It does not cite the exemplary study report of the IIT-Madras whose experts had studied the 2023 December Oil Spill under the Order of the NGT(SZ) (Ref-14). 

The EIA is unaware of the classification of the stream network in the region based on their vulnerability to flood inundation put forward in the Report of IIT-M.

The Report classifies the stream network into three zones. The northern zone spans between Ennore Creek Mouth to the ETPS northern boundary. The Mid-Stream Zone extends from ETPS northern boundary to the Manali High Road Bridge located on the North Eastern edge of CPCL. The southern zone extends from the Manali High Road Bridge to Kodungaiyur STP. 

IIT-M Report states:

" The midstream stretch of Buckingham Canal extending from the junction of Kosasthalaiyar river and surplus canal from Redhills upto ETPS is the crucial area to pay attention. The surplus from Puzhal and Poondi Lakes discharged high quantum of water into the two Kosasthalaiyar River branches which trapped the oil in this mid-stream stretch. The flood water rose to 7 to 9 ft in this section carrying the oil with it, over the Buckingham Canal bank into the adjoining residential and industrial areas of Ernavoor (note: this is ETPS) and Sathiamoorthy Nagar. Once the flood water/surplus water receded, the oil must have flown downstream into Kattukuppam all the way to Nettukuppam.” (Fig-8).”

“The High Flood Level at Ernavur during this flooding event was 7.5 feet” (see Appendix for Pictures From IIT-M Report). The Map in page 31 of the Report shows that ETPS Expansion Site was flooded and was severely contaminated with Oil."

Fig-8 

The area referred to in the IIT-M report where oil spill due to flood inundation happened most is the land adjacent to the Tri-Junction of the Amullavoyal (Puzhal or Red Hills Surplus) Canal, Buckingham Canal and Kosasthalaiyar River. The Tri Junction is the spot where Kosasthalaiyar River changes its direction from its NW-SE Course to a S-N Course abruptly. Whenever there is a storm followed by a heavy rain with Puzhal Reservoir releasing its surplus water and the B-Canal flowing to the brim, the Tri-Junction  is challenged by tides that flow in the N-S direction, K River flow in the NW-SE Direction, Puzhal Surplus and B Canal flow in S-N direction at once.  This challenge to the flow is the cause for Kosasthalaiyar to slow down considerably and meander to form two large braids in the 10 km stretch between Seemapuram Reservoir and Sadayankuppam. (Fig-9) This is the region where it spreads its alluvium across the low lying flood plains around its course; and it is exactly here in this alluvial flood plain that the Ash Ponds of ETPS are located. The Main Land of ETPS is located on the eastern side of this Tri Junction. These lands all around bear one single mark : they are Low Lying and will get inundated whenever there is a high river flow or extreme tidal action. It is exactly for the same reason, this region is endowed with mangroves.  The EIA does not record this crucial fact.

What will happen if the altitude of the ETPS Site is changed from "- 3.095 m below mean sea-level" to "+9.15 m above sea level"?

The EIA states: 

"Some portions of the land are being filled, graded and compacted for getting the required plant level of + 9.15 m above MSL. Excavated earth will be utilised for levelling the ground.”(Ref-15)

Such an alteration of the altitude of the land adjoining the flow-challenged Sadayankuppam-Ernavur Tri-Junction will increase the stress to the river-canal-tidal flow many folds. (Fig-9) This would have devastating effect not only on the local environment but also the environment of Chennai as a whole.

Fig-9

An increased back flow in the south direction due to the obstruction caused by a higher level ETPS site would flood Manali Industrial Area, Kodungaiyur Dump Yard and the adjoining locations. The entire landmass from Peravallur, Ambattur, Perambur, Thiru-Vi-Ka Nagar , Madhavaram and Thiruvottiyur whose drains depend solely on the North Buckingham Canal would be challenged by the stress that the flow in the Buckingham Canal would face at the Tri Junction due to the back flow from the filled up ETPS Site.  These areas which get inundated even after a small shower because of the decreased carrying capacity of the Buckingham Canal would suffer many folds if the ETPS Site is filled up to +9.15 AMSL. 

The extent of environmental havoc by a flooded Manali Industrial Area was show-caused by the CPCL Oil Spill of 4 December 2023. 

The EIA is ignorant about all these dreary possibilities.

What are the lessons from the historical floods that had affected this area?

The flood records of the years 1721, 1791, 1943, 1975, 1986, 2005, 2015 and 2023 illuminate the flood dynamics in North Chennai. 

1. The record from 1721 is unique. This is about a flood that was caused by tides that entered the land through Ennore Creek and travelled upto Tondiarpet to destroy the Paddy fields all along the low lying area. This was a period before the formation of the Sadayankuppam-Ernavur Tri-Junction (Ref-16). 

The Report on the Flood (caused by a storm that probably occurred in November-December 1720) states (Ref-17):

"The Inhabitants have been very diligent this year, and have sow’d paddy a great deal more Land than they did last, which promised an extraordinary produce; but the late Storm spoiled them a great deal of Paddy, particularly  Tonderwood village, the sea having flow’d in at Cattawaack village (by Ennore backwater, 11 miles north of Fort St George), and so run through Trivetore, Sattangoord, Tonderwood, and so to this place, which has kill’d the paddy, and made Ground Salt where ever it came, and has occasion’d this second time of sowing to come up very thin, and will afford but a small produce…(p.c., vol.iii, 3rd Jan 1721)” (Fig-10)

Fig-10 

It needs to be remembered that this tidal inundation could happen in Tondiarpet even before the Kosasthalaiyar River at Ernavur and the the Elambore River (at the present day Basin Bridge) were joined by the Cochrane Canal. Repeated danger of severe tides entering the Canal from the Ennore Creek into the canal stretch south of Sadayankuppam highlighted the low altitude of this entire region (less than 5 meters MSL). (Fig-11) It was one of the primary reasons for constructing the first Tidal Lock at Sadayan Kuppam in the Buckingham Canal in the year 1854 (Ref-18). Today, if such an event occurs, it could inundate Chennai Petroleum Corporation Ltd (CPCL) and the industries around. It would flood and devastate the ETPS Ash Ponds and the Project Site.
Fig-11

2. The 1943 Flood (Ref-19) was the first one that highlighted the limited capacity of the North Buckingham Canal to carry the storm water from Madhavaram-Ambattur-Perambur-Thiru-Vi-Ka Nagar and Thiruvottiyur West. To reduce the flow in Cooum River, a regulator was constructed to divert the water into Kosasthalaiyar River in 1914. To prevent events like the 1943 floods affecting areas around Cooum River, the regulator height was increased and was opened on 10.10.1947.

3. The 1976 flood (Ref-20) had submerged the area where the ETPS Ash Ponds are located from the year 2000. Areas around the Amullavoyal Canal were submerged. It also revealed the inefficient drainage capacity of the North Buckingham Canal. (Fig-12)

Fig-12

4. The 1985 Flood Event (Ref-21) highlighted once again the severity of flooding due to insufficient carrying capacity of the North Buckingham canal. (Fig-13)

Fig-13

5. The 4 December 2005 Flood (Ref-22) had caused complete inundation of all the areas around the Sadayankuppam-Ernavur Tri-Junction. The ETPS Site and the Ash Ponds were submerged. Areas drained by North Buckingham Canal (Madhavaram, Ambattur) were inundated by waist deep water. (http://www.hindu.com/2005/12/04/stories/2005120412950100.htm) (Fig-14)

Fig-14

6. The 8th November to 14th December 2015 Floods (Ref-23) had inundated areas drained by North Buckingham Canal. ETPS Ash Ponds were flooded. Kodungaiyur, Manali, Sadayankuppam and Old Nappalayam were inundated. (Fig-15)

Fig-15

7. Continuous rain on 4th December 2023 (Ref-24) which forced Puzhal Reservoir to discharge its surplus in the Amullavoyal Canal, flooded Kosasthalaiyar River and Buckingham Canal caused an extreme hydrological stress at the Sadyankuppam-Ernavur Tri Junction causing a severe back flow of flood waters that entered the CPCL premises in the Manali Industrial Area causing an Oil Spill. This Oil Spill was then carried over by the flood waters to inundate the areas around Ernavur including the ETPS Site.

The way forward:

The EIA consultants want to fill the site and raise its altitude. The EIA states:

"High Flood Level (HFL) in Kosasthalaiyar River is +8.550m above MSL*. The Sea level is at +6.095m above MSL; High Tide Level (HTL) is at +6.720m above MSL. Low Tide Level (LTL) is at +5.580m above MSL. Depth of Maximum Rainfall Excess is 86 mm. Hence providing a free board of 0.5 m level with HFL and Depth of Rainfall Excess will provide a complete safety to the plant from the flood occurrences. The safe level for the plant will be MSL +9.136m (8.55+0.086+0.5). Existing Ennore Thermal Power Plant is already situated at an elevation of MSL +9.150m.”(Ref-25)

This desire might save ETPS from flood inundation but will put all the land mass from Ambattur to Manali Industrial Area in jeopardy. Even its own ash ponds will have to face a challenging hydrological environment. (Fig-16)

Fig-16

THE EIA IS FLOOD BLIND. IT IS COMPLETELY IGNORANT ABOUT THE LOCAL TOPOGRAPHY AND ITS HYDRO DYNAMICS. IT HAS WANTONLY PRESENTED DEFRAUDED DATA ABOUT THE DISTANCE BETWEEN THE SITE AND THE K-RIVER.

HENCE, IT SHOULD BE SET ASIDE. THE ACCREDITION OF THE EIA CONSULTANTS SHOULD BE WITHDRAWN.

A FLOOD HAZARD STUDY FOR THE ENTIRE NORTH CHENNAI AREA SHOULD BE UNDERTAKEN. IT IS IN THE BACKDROP OF ITS CONCLUSIONS, THE ETPS PROJECT SHOULD BE EVALUATED.

THE ETPS ASH PONDS SHOULD BE CLOSED AND THEY SHOULD BE RESTORED ECOLOGICALLY. THE DAMAGED OLD NAPPALAYAM DRAIN SHOULD BE RESURRECTED.

WITHOUT TAKING THESE STEPS, ALLOWING THE PROJECT WOULD HARM CHENNAI AND ITS PEOPLE BEYOND REVIVAL.

Reference:

1.THE HINDU, 10 January 2002, http://www.hindu.com/thehindu/2002/01/11/stories/2002011101960500.htm

2.1:50000 Survey of India Map No.D4408

3. Google Earth Pro - Historical images

4. Letter dated 18.08.2019 From Er.K.Subash Chandra Bose TANGEDCO to Shri Kerketta, The Director, Impact Assessment IA.II (T) Division MoEF - . Lr.No.SE/C/P&E/EE/EMC/AEE/C/F.ETPS Exp TPP/D. 249/19, dt.18.9.19 

5. No.46 Ernavur Map, Published at Page No 190 of the District Gazette of Chingleput District, dated 1.7.1968

6. See Appendix - The Long Tortuous Course of ETPS Expansion TPP

7.Google Earth Pro - Historical images

8. ETPS Expansion EIA July 2019, p-3.68

9. Area calculated by digitising the Ash Dykes in Google Earth Pro

10. Generally MSL of Chennai is considered as 6.7 meters (22 ft). However, the ETPS Expansion EIA mentions it as  +6.095m AMSL (ETPS   Expansion.  EIA p- 4.47). To compare the data produced in the EIA Report and my own contour data generated using SRTM30, I have used this value to calculate the AMSL from the Contour altitude data.

11. Available at https://czmp.ncscm.res.in/. - Note: Flood Hazard Line Digitised to make it visually prominent

12. Available at: http://www.chennaicorporation.gov.in/gcc/pdf/49107-009-emr-en.pdf. page 2

13.ETPS Expansion EIA TOR-8

14. Available at:https://greentribunal.gov.in/sites/default/files/news_updates/OA%20180%20of%202023%20Report%20by%20TNPCB_0.pdf 

15. ETPS Expansion EIA p-3.68

16. Buckingham Canal was known as Cochrane Canal initially. It was in 1806, when the Cochrane Canal was completed  by linking the northern part     of the Elambore River ( a river that drained Otteri Nullah and Purasaivakkam Drain at the present day Basin Bridge and flowed southward for 2.5 km to meander east and south later to join Cooum River at its mouth) with the Kosasthalaiyar River at Ernavur to reach the Ennore Creek, the drains of the areas from Ambattur, Peravallur, Perambur, Thiru-Vi Ka Nagar, western Thiruvottiyur were artificially diverted from Cooum Basin to Kosasthalaiyar Basin. Creation of the Puzhal Reservoir to meet the drinking water needs of  Madras also created its surplus canal (variously called as Amullavoyal Canal, RedHills Surplus or Puzhal Surplus Canal) in the year 1876. Hence, the Sadayankuppam-Ernavur Tri-Junction came to existence only from  1876. (See Fig-10)

17. Henry Davison Love, “Vestiges of  Old Madras 1640-1800” Vol 2, page 193

18. A.S.Russel, “History of the Buckingham Canal Project: Descriptive Account of the Canal and its Principal Works - A Guide to its Future   maintenance”, 1897, Chapter 2, Page 18

19. The Hindu 31 July 2016, https://www.thehindu.com/features/metroplus/memories-of-madras-story-of-a-submerged-city/article2650132.ece

20. Source: GCC - 25 November 1976 - The Hindu 9 December 2023

21. Source: GCC - 11 & 13 November 1985 The Hindu 9 December 2023

22. https://data.opencity.in/dataset/chennai-floods-2005-data

23. https://data.opencity.in/dataset/chennai-floods-2015-data - National Remote Sensing Centre’s (NRSC)Flood Inundation Data

24. https://greentribunal.gov.in/sites/default/files/news_updates/OA%20180%20of%202023%20Report%20by%20TNPCB_0.pdf

25.ETPS Expansion EIA p- 4.47

Appendix: 

Pictures from IIT-Madras Study on Oil Spill following Cyclone Michaung

At Ernavur: