SCIENTIFIC SOLUTIONS FOR RESOLVING MULLAPERIYAR DAM PROBLEMS

Prof.T.Shivaji Rao,Director, Center for Environmental Studies, GITAM University, Visakhapanam.
http://aam-aadmi-senses.blogspot.com/2011/12/why-no-solution-is-better-for.html?showComment=1325915239042#c7784946802355145765 

 

Note: This article is prepared with the fond hope that the Governors of Tamilnadu and Kerala may kindly advise their Chief Ministers to discuss the following alternate proposals on solving Mullaperiyar dam so that they can prevent misunderstandings between Tamilians and Keralites and maintain peaceful conditions without any social unrest for promotion of the development of the states.

Mullaperiyar dam was constructed in 1887 with limestone and a mixture of burnt brick powder known as Surkhi including Sugar and calcium oxide as per construction practices of the olden days.  The cost of the dam was Rs.1.04 crores with a height of 176ft. including the foundation depth and a length of 1200ft.  The length of the dam at the foundation level is 200ft. The watershed is 4678 acres at a reservoir level of 136ft. and 8591 acres at the reservoir level of 155ft.   The dam has low level saddle portion on the left and right sides.  The left side saddle was filled up with embankment of 221ft length and 53ft height and join to the main dam.  The right side low level saddle was used to discharge o the flood waters during peak rains as an escape route with open sluices with 11ft lower level than the top of the dam.  But in 1908 that spillway sections were further deepened to discharge more floods by construction of a spillway dam with 10 spans each of 36ft width and with 16ft. high spillway gates.  Since the dam is located in a triangular river section.  Most of the reservoir upto 125ft. depth had to be used as a dead storage of about 6 TMC with a gross storage of 16TMC and live storage of about 10 TMC.  Peak flood in Mullaperiyar in 1943 was 8453 cumecs.  But the PMF must be taken 1.5times the historically recorded flood and hence the PMF must be estimated at 12680 cumecs based on the revised calculations made for the new Machchu dam in Gujarat.  According to experts sudden floods of 10,000 cusecs to 1,20,000 cusecs are constantly occurring in Periyar river which means that inflows will be 1 to 11 TMC perday.  Hence peak floods of 1 to 10 days will meet the water requirements of Tamilnadu.   If FRL is over and above 104ft Tamilnadu gets water through the tunnel at the ground level of 104ft.  disasterresearch.net/drvc2011/paper/fullpaper_44.pdf 
[Disaster management was unknown in olden times and hence Mullaperiyar is defective in Design]
http://en.wikipedia.org/wiki/Mullaperiyar_Dam   [Ddetails of Mullaperiyar agreements and present position]

LIFE SPAN OF THE DAM:    The original British engineers anticipated 50 years as the lifespan of the dam and today the dam withstood for more than 116 years and because of its unconventional construction it has to be replaced by a new cement concrete dam built for the same height a few meters below the existing dam.  According to International experts the maximum life span of a dam is 100 years and hence a new dam must be built in place of the existing dam (See web:  http://www.waterpowermagazine.com/story.asp?sc=2055594  .

In 1974 Tamilnadu obtained lease to use Periyar water for power generation and Kerala permitted withdrawal of 70 TMC of water every year by payment of Rs.40,000 per year whereas Tamilnadu is paying Rs.3 crores for AP for 1 TMC of water from Telugu Ganga project. After the dam burst at Morvi in Gujarat in 1979 when thousands of people were killed in the floods, Kerala began to worry about the safety of the Mullaperiyar dam and consequently about 35 lakhs of kerala people may be washed away into the Arabian sea. Recently due to heavy rains the FRL in the dam rose to 139ft as against the stipulated level of 136ft. 

CONTROVERSY ON WATER STORAGE:  Kerala is afraid of Periyar dam break due to aging, water leakage and peeling of construction material in the dam and emerging earthquakes of higher magnitude.  Since the Supreme court has advised the FRL of the dam to be raised to 142ft to the advantage of Tamilnadu, Keralites are objecting and demanding for reduction of FRL from +136ft to +120ft and naturally this drastic reduction is bound to ruin the agriculture in several districts of Tamilnadu in whose interest this dam was originally constructed.  Thus the present controversy is based upon the demand of the Keralites to construct a new dam to protect the lives and properties of Kerala due to a sudden burst of the dam while Tamilnadu is afraid of the loss of agriculture and power generation due to the reduction or denial of their normal water supply as per agreement of 1974 and thereby are demanding for increasing the height of water storage from FRL +136ft. to + 142ft in the first instance.  Supreme Court accepted this on        27-2-2006.   On 29-4-1980 Central Water Commission recommended to raise the water to 145ft even after strengthening the dam.  But Kerala insisted that the level should be maintained only at 136ft. 

INCREASING WATER AVAILABILITY FOR BOTH STATES:   Now Environmentalists find that the fears of both Kerala and Tamilnadu people are highly justified and an amicable solution must be found by inviting eminent irrigation engineers and distinguished environmentalists with profound knowledge in water resources management and dam break analysis , risk analysis and disaster management so that they can make a cost benefit analysis of different alternate project proposals that can be implemented to make Tamilnadu and Kerala to get higher quota water than before from a newly constructed cement concrete dam by replacing the existing Mullaperiyar dam by convincing  both the state Governments.  This requires the involvement of central Government which has to create a corporation for this dam on the lines of the interstate multipurpose projects on Narmada river and Bhagirathi river by creating corporations like the Tehri Hydro Development project in Uttara Pradesh and Sardar Sarovar Corporation in Gujarat for harnessing the waters of those rivers.  The Central Government cannot remain a silent spectator but play a pro-active in support of the Federal structure under the Indian constitution. 

SOLVING THE PROBLEM:  Some of the suggestions for resolving this Mullaperiyar project issue are in the following lines.

1)      As requested by Kerala people the water level in the lake can be maintained at FRL +120ft.  The amount of water supply demanded by Tamilnadu from Periyar lake from FRL +136ft can be supplied even by keeping FRL at +120ft by lifting the water or by filling the lake whenever the water levels get depleted and this shortage can be made up by cloud seeding operations.  Cloud seeding operations are conducted by 50 countries in the world for more than 40 years and as confirmed by China which uses 37,000 people every year for cloud seeding operations to get about 1800 TMC of water at a cost benefit ratio of 1:28 for  both irrigation and hydro-power generation.  If Chief Ministers of Kerala and Tamilnadu make immediate visits to China, Tasmania, New South whales, Texas, Honduras and California along with their experts they can prepare cloud seeding operation reports and implement them to augment annual rainfall by 40% in Periyar lake which has an annual rainfall of about 1000mm and the rains occur almost in the 4 out of 5 days in a year with annual flodds of 1 to 11 TMC per day.  Kerala can fill up Idduki reservoir by this  method as followed by Tasmania for the last three decades with a cost benefit ratio of 1:20

2)      Since the levels of water proposed to be maintained at FRL+120ft as demanded by the Keralites in the interests of the safety of the dam , Tamil nadu receives diminished  flows from Periyar lake.  Since the present level of the tunnel is about 104ft in Tamilnadu, now investigations may be carried out to find out if adequate water can be supplied to Tamilnadu either by pumping or by using siphon spillways or other suitable works from FRL +120ft. also.

3)      In order to avoid any earthquake risk to the dam the Kerala state must conduct air borne magneto meter surveys and try to identify any emerging hidden faults that can trigger large earthquakes that produce high peak ground accelerations of more than 6 magnitude as conducted by the US geological survey for protecting the townships of Portland Vancouver in USA.

4)      Since Kerala people do not know when a large earthquake may occur to make the Periyar dam burst they have to always live in tension even during sleep in the nights similarly they do not know when a cloud burst can occur to provide 1m depth of rainfall in a day as had happened recently in Mumbai.   They have to be constantly vigilant to monitor when such clouds cluster during cyclones and other cloud burst seasons and to prevent such massive clouds raining over Periyar lake catchment.    They should adopt cloud seeding technology to stop unwanted rainfall in Periyar catchment as implemented by China  during the opening and closing functions organized for the Olympic games of 2008.  For this purpose they must take the advice of cloud seeding experts from foreign countries or those who worked for 5 years for the AP State Government cloud seeding programmes during 2004 to 2010.

 http://expert-eyes.org/mulla1.html