Hyderabad: The unprecedented rains in Telangana last week led to flooding of two pump houses of the Kaleshwaram Lift Irrigation Scheme (KLIS). The natural calamity, however, has fuelled a spate of unsubstantiated charges by politicians and some others about the efficacy, sustainability and functioning of the project. Here is the point-by-point analysis by OSD in […]
Hyderabad: The unprecedented rains in Telangana last week led to flooding of two pump houses of the Kaleshwaram Lift Irrigation Scheme (KLIS). The natural calamity, however, has fuelled a spate of unsubstantiated charges by politicians and some others about the efficacy, sustainability and functioning of the project. Here is the point-by-point analysis by OSD in the Chief Minister’s Office, Sridhar Deshpande on the issues raised by the Telangana Joint Action Committee (TJAC).
Here are excerpts from the clarification
TJAC: Bad design and construction quality of Kaleshwaram project has been exposed. The State government did not maintain quality and designs approved by the Central Water Commission (CWC). As a result, the Annaram and Medigadda pump houses got submerged in the floods though the water level remained way below the CWC approved levels.
Clarification: The CWC gave hydrology clearance to the designs for Kaleshwaram project to withstand flood frequency of upto 28.8 lakh cusecs after taking into consideration of 500 years of data. Accordingly, 85 gates were also fixed to the barrage. The highest flood level of 107.05 metres was recorded at Kaleshwaram in 1986, based on which the CWC gave approvals for the full reservoir level, gate hoisting level and bridge level. The pump house and protection walls too were designed accordingly. As per the Commission, the flood level of 103.5 metres in Godavari River is considered as warning level and 104.75 as danger level.
But on July 14, the Godavari River recorded 108.18 metres at Kaleshwaram which was above the previous record of 107.05 metres registered in 1986. Further, the flood frequency of about 28-29 lakh cusecs was recorded at Kaleshwaram as per the CWC which indicates that the project faced an unprecedented flood level. Hence, it may be concluded that the pump houses submerged due to unprecedented flood, but not due to bad design or construction quality.
TJAC: Due to the impact of barrages constructed, the river flow channel got narrowed and as a result, the water levels before the barrages is increasing due to the back water effect. Though the flood level during recent rains was lesser than previous years, it resulted in increased water levels before the barrages due to the back water effect. The pump houses got submerged as the back water effect was not taken into consideration during their construction. The argument that the pump houses were flooded due to unprecedented water levels, is false. Though the flood was low, the pump houses got flooded as the water in the barrages was stored over a period and released at once. An attempt is being made to divert the public attention from the State government’s bad management of reservoirs and flood flow.
Clarification: Engineering experts who could not differentiate between dams and barrages are trying to confuse people by citing back water effect. It may be noted that the dams and barrages are designed along with the gates, only after taking into consideration of back water effect. The dams are meant for water storage and the barrages are only diversion structures. While both the concrete walls and gates are utilised for water storage in dams, the barrages completely depend on gates for water storage. During floods, the barrage gates are lifted and kept in free flow condition to allow free flow of water downstream. The gates of Medigadda barrage were increased from the proposed 77 to 85 in order to avoid afflux and improve buffer levels.
The issue raised by TJAC persists in dams, but cannot be applied to barrages. As the gates are lifted and kept in free flow condition during floods, the water will flow in the river without any obstruction. All the barrages at Medigadda, Annaram and Sundilla are kept in free flow condition, since July this year. Hence, the situation of back water effect does not arise.
The water levels of any river rise due to heavy inflows beyond its natural flow capacity. On July 13 and 14, the inflows from Pranahitha near Kaleshwaram were recorded at more than 29 lakh cusecs. As Godavari River cannot accommodate such huge inflow at once, the water level crossed 108 metres. It may be reminded that though there was no barrage on Godavari River in 1986, the water level reached 107.05 metres. People with no knowledge about the river hydraulics are making baseless arguments and trying to create confusion among people by applying the conditions required for dams to Kaleshwaram barrages which are in free flow condition.
It may be noted that the Polavaram project is a storage reservoir with gross storage capacity of 194 TMC where the live storage is only 75 TMC which can be used through canals. Thus, about 119 TMC water is always stored in the project which is also named as dead storage level and would have a back water effect on Bhadrachalam and surrounding areas which fall in the back water areas. Considering the climatic changes, the Telangana government has been demanding for a detailed study on the impact of global warming on Polavaram project back waters and initiate protective measures in the villages on the banks of Godavari River.
Further, when the Godavari River is in full spate, the water flow from smaller streams cannot join it and it will be repelled resulting in inundation of upper catchment areas in the these streams. For instance, Chandanapur Vaagu could not joint Godavari River and the water got repelled. The water overflowed on the earthen bund constructed to protect Annaram pump house and submerged the latter. While the afflux in Chandanapur Vagu never crossed 0.5 metres earlier, it was nearly 1.5-2 metres during recent rains. A similar phenomenon in Bokkela Vagu led to inundation of Manthani town.
TJAC: Gates of the pump house got damaged leading to flooding of Medigadda pump house. This is an issue of construction quality and it should not be considered as a calamity.
Clarification: When the flood level is beyond the capability of any project, it is bound to get damaged. But it can be ascertained only after the water recedes at Kannepalli pump house which was constructed at about 20 km upstream from Medigadda pump house. It may be noted that the Medigadda pump house got submerged as the water level surpassed the high flood level (HFL) in its fore bay area. One must note that the floods were unprecedented and it cannot be attributed to faulty design.
It may be recalled that due to heavy floods in Krishna River during 2009, the Srisailam hydel power plant, Srisailam Left Bank Canal tunnel and even Kurnool town were inundated. Though the Srisailam dam has discharge capacity of 13 lakh cusecs, about 25 lakh cusecs reached the project which led to flooding. One cannot blame it on faulty design. Similarly, the Kadem project too witnessed during this monsoon season with inflows reaching 6 lakh cusecs as against outflow capacity of 3 lakh cusecs, posing a severe threat to the habitation along the Godavari River till it reaches Bay of Bengal. The TJAC should stop politicising this natural calamity.
TJAC: The State government is trying to hide the technical faults and designs of Kaleshwaram project under the guise of excess publicity terming it as an engineering marvel. If the shortfalls are not addressed immediately, the project could pose a bigger threat to the people of Telangana in future. We have published two booklets in 2016 and 2018.
Clarification: The booklets published by TJAC on Kaleshwaram project are filled with false allegations and the same were countered by the engineers of Telangana exposing the lack of logic as well as technical expertise in the arguments. The Telangana Retired Engineers Association had also published a book ‘Telangana’s lifeline-Kaleshwaram project’ explaining how the project became a growth engine for Telangana propelling its development on all fronts. One cannot brush aside the benefits of the Kaleshwaram project especially after its redesigning.