Paryavaran Mitra director Mahesh Pandya’s letter to Prime Minister Narendra Modi on urgent need to desilt Sardar Sarovar and other dams, stop illegal river sand mining, and protection of ponds/wetlands in Gujarat:
First of all, I would like to congratulate you on the occasion of 75th anniversary of India’s Independence. On the occasion of Azadi Ka Amrut Mahotsav, we welcome your suggestion of constructing at least 75 water reservoirs in each district for the celebration of Amrut Mahotsav. In the Mann Ki Baat sessions of March 27, 2022, June 29, 2021, November 25, 2021 and June 29, 2019, the emphasis on water reservoirs was taken forward on Azadi Ka Amrut Mahotsav.
Within 17 days of your becoming Prime Minister, the decision to increase the height of the Sardar Sarovar Dam to 138 meters with an objective of abating scarcity of drinking and irrigation water. This would also contribute to Saurashtra Narmada Avtaran Irrigation (SAUNI) launched during your chief ministership in the state of Gujarat.
However, I would like to draw your attention to the fact that desilting is the first and foremost requirement of the reservoirs, as continuous silting reduces the storage capacity. According to a recent report in a local newspaper, the Sardar Sarovar dam is filled with 53% of its capacity and only 39% of storage is available in the reservoir for usage. In consecutive past two years 2020-2021, Gujarat has witnessed almost 102% of rainfall in monsoon. Various dams of Saurashtra also have silted significantly leading to reduced storage capacities of water. If the monsoon is prolonged, there will be an acute scarcity of water.
In the last year’s Gujarat State Legislative Assembly session dated March 9, 2021, in one of the Star
Questions, it was mentioned that the survey about the present silt level in Sardar Sarovar Dam is not conducted yet.
In addition to this, the information is derived from the un-star question of the Gujarat State Legislative Assembly dated March 24, 2022, which mentions that the silt survey of many large and medium dams of Gujarat was conducted in 2021. While for some dams, the survey has taken place in the years 2001, 2009, 2017-18, no action is taken for removal of silt. The reason stated for non-removal of silt was that the desilting process is done ad hoc manner and not scheduled. Hence, the budget allocation for this activity is not regular and will be done, when this activity is to be taken up.
As per the handbook for Assessing and Managing Reservoir Sediment, published by CWC in February 2019, the same issue is discussed and we quote: (Page no. 23 – 24).
“Sediment-induced problems induce a number of adverse impacts not only within reservoirs but also in both upstream and downstream areas of river systems with dams. Some of the adverse effects, induced by sedimentation and erosion processes in a river system with reservoirs, are outlined as follows:
- Reduction of storage volume in reservoirs due to sediment deposits.
- Flood level increase upstream of the reservoir (higher than estimated during design) due to changed river slope.
- For flood control dams and reservoirs, reduction of storage implies altered regulation and operational strategies leading to less effectiveness of flow/flood management, and thus more risk.
- Erosion and shifting of river banks and bed incision in downstream areas. Coastline erosion due to the lack of fertile silt and nutrient supply.
- Adverse effects on agricultural activities in downstream areas due to lack of fertile silt and nutrient supply.
- Impact on aquaculture like fisheries, and aquatic plants in downstream areas.
- Possible alteration in static and dynamic loads on structures due to large deposition in front of dam/spillway.
- Erosion of turbines and its accessories.
- Malfunctioning and clogging of hydro-mechanical equipment, such as flow control gates, sluice outlets and vents.
- Abrasion and cavitations of concrete structures like spillways, roller buckets, cut-off wall, and sediment bypass tunnels and channels etc.
- Deterioration of aquatic environments, ecology, water and sediment quality leading to eutrophication, contamination of sediments in the reservoir (this is usually the case due to industrial effluents, reaching the reservoir).”
Also, On page number 30 of this report, in figure 2.2, it is shown that there are 60 dams in Gujarat whose storage capacity has been reduced by 2.4 billion cubic metres. This situation depicts that, if the silt from the Sardar Sarovar Dam and from other dams is not removed, it will directly affect the efficiency and usefulness of SAUNI Yojana.
The second issue, we wish to draw your attention to is about high level of illegal sand mining in river beds in Gujarat.
We wish to draw your attention to illegal mining in the rivers of Gujarat. A local newspaper reported that 182 rivers of Gujarat are excessively mined leading to desertification and reduced flow of water. This has directly impacted groundwater levels too. The sand present on the banks of the river curtails the velocity of the flow water-reducing soil erosion. Sand mining will result in flowing away of river water into the ocean. This impacts the base flow of water in the river, resulting in immediate drying of rivers post-monsoon.
The third issue, we wish to draw your attention to is about the level of river pollution in rivers of Gujarat.
On 28/6/2019, in the Lok Sabha, as a reply to the Un-starred Question, the Ministry of Environment, Forest and Climate Change (MoEFCC) has answered that there are 20 heavily polluted rivers in Gujarat.
On 5/12/2019, The Ministry of Jal Shakti also reply to an Un-starred Question that there are 20 rivers in Gujarat that are highly polluted.
Pollution in rivers coupled with uncontrolled mining of sand would result in water scarcity across the state. Untreated sewage is dumped in freshwater relentless making potable water so polluted that it can not be used for drinking.
The fourth issue we wish to draw your attention preservation of water reservoirs (Ponds/Wetlands).
We sincerely welcome your appeal of making at least 75 lakes/ponds/water reservoirs in each district. But, in Gujarat, there are many lakes and ponds which are filled and converted in land for town planning and other development schemes. In this context, the Paryavaran Mitra has drawn the attention of the government of Gujarat and the hon’ble court. In this matter, we had approached hon’ble Gujarat High Court through WP(PIL)144/2021. On which the Hon’ble High Court gave an oral order on 17/2/2022, in which it has directed the Gujarat Government on the issue of “preservation of water reservoirs”. We have also enclosed a brief crux of those judgements (Attachment 5) in this letter.
We strongly believe that “Nal Se Jal” Yojana will achieve its objectives, if the following suggested works are carried out effectively. We kindly request you to consider the following suggestions in solve water crisis of Gujarat:
(1) The silting survey of Sardar Sarovar Dam should be done on an immediate basis and followed by this, the desilting process should be carried out by proper method. (As per directed by Handbook for Assessing and Managing Reservoir Sedimentation published by CWC)
(2) The desilting Process should be carried out in all the medium as well as small dams of Gujarat.
(3) Illegal sand mining must be stopped as soon as possible.
Please give a direction to the Government of Gujarat to follow and implementation of the following judgement of honourable Gujarat High Court for protection of wetlands/ponds/water reservoirs:
(1) Paryavaran Mitra versus State Of Gujarat R/WRIT PETITION (PIL) NO. 144 Of 2021 Dated: 17/2/2022
(2) Shailesh R. Shah versus State Of Gujarat and others reported in 2002(3) GLR 2295
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