Course Forum

Panchet & Khadakwasla Dam failure

Panchet & Khadakwasla Dam failure

par Dattakumar Chaskar,
Nombre de réponses : 3

Dear Participants,

I am sure you must be reading  Dam Failure case studies with lot  of interest, as all  the case studies throw light on  the deficiencies in planning, design, construction and operation of the reservoirs.  

Most of the case studies given in  damfailures.org are from western part of the world.   There are many failures of Dams in other parts of the World as well.   

In fact, I would like to draw the attention of Indian Participants  to the case of  Panshet & Khadakwasla Dam Failure.   As many of you know, NWA is located just 2 km downstream of the Khadakwasla Dam, which breached on 12  July 1961. NWA was not there at that time, but The Central Water & Power Research (CWPRS), Pune which is situated just one kilometer downstream of the dam recorded the  failure on  motion camera.

Khadakwasla Dam, which was Masonry Dam (backed by earthen mass) breached due to overtopping. The reason for overtopping was failure of upstream Dam called “Panshet” situated about 20 km upstream of Khadakwsla Dam.    Panshet was an Earthen dam, getting filled up for the first time  during the monsoon of 1962.  The main reason of failure of the Panshet Dam was improper construction schedule; issues with design and incomplete  construction of sluice conduit; incomplete gates & hoists arrangement  etc.  All these factors lead to erosion  of the conduit and consequently dam failure.     The flood wave coming from Panshet Dam  reached downstream Khadakwasla Dam, which was an older dam ( It was not designed to account for  uplift pressure nor designed for overtopping).   Flood waves overtopped the Khadakwasla Dam. The excessive stresses developed in the dam resulted in its failure.   Eyewitness say that  that a part of dam opened up like single  door leaf with hinge on the right side.  The opening in the Dam is clearly seen in the video. Resulting flood wave inundated  large  part of Pune city.   The Khadakwalsa dam acted as  a buffer  for some time and allowed the major population of Pune city to get to safer place, thus limiting the loss of life and property.

The video of CWPRS is available on Youtube at the link

Please note that this video is of the Khadakwasla Dam and not of upstream Panshet Dam (which failed first) .

I am sure the video will be of interest to all Indian as well as International Participants ( though the video quality is bit poor as it belongs to 1960 era). The film also shows the efforts of Engineers in putting sandbags before the breach and also the devastation scenes from the city after the flood.

Regards,

..Dattakumar


En réponse à Dattakumar Chaskar

Re: Panchet & Khadakwasla Dam failure

par Pankaj Sharma,
Sir, 

 Your description of Panchet and Khadakwasla dam failures reminds me of the case study of Lawn Lake Dam located in Rocky Mountain National Park upstream of Estes Park, Colorado. 

 Due to man-made causes, failure of an upstream earthen dam happens and which in turn causes failure of a concrete dam downstream, further compounding the losses. 

Lawn Lake dam was an embankment dam and constructed in 1903 and owned by an irrigation company. It fell within the National Park boundary when the Park was established in 1915. The reservoir was at almost 11,000 foot elevation and the dam enlarged a natural glacially-formed lake. The dam was raised in 1931 to 24 feet high and stored a maximum of 817 acre feet of water. A 3-foot diameter, riveted steel outlet pipe was used for releases. A direct-buried gate valve was located in this pipe directly under the crest of the dam. The dam was assigned a “moderate” downstream hazard potential. 

 Due to its remote location with challenging access, inspections of the facility were relatively infrequent. A number of issues were identified at the dam and documented in inspection reports in 1951, 1975, 1977 and 1978. Between 5:00 and 6:00 AM on July 15, 1982, the dam failed suddenly, releasing 674 acre-feet of water. There was no warning. The peak flow was approximately 20,000 cfs. 

The flood went out the east end of Horseshoe Park, filled and then overtopped a 17-foot-high concrete dam called Cascade Dam. The maximum overtopping was 4 feet. After 17 minutes of overtopping, Cascade Dam gave way and a new flood surge of 16,000 cfs poured through the breach. 

The flood swept motels, residential structures, and mobile homes off their foundations. In the town of Estes Park, debris-laden, muddy water up to five feet deep (6,000 cfs) poured through the business district. It damaged 177 businesses (over 90% of the businesses). Damages totaled $31 million and a total of three lives were lost. 

The State Engineer performed an investigation and issued a report 8 months following the failure. The report concluded that “… the failure occurred due to leakage under high pressure from the leaded connection of the outlet pipe and valve, causing progressive piping of the dam embankment in the vicinity of the outlet pipe during periods of high reservoir levels and gate closure and sudden collapse of the embankment allowing rapid evacuation of the reservoir.”

En réponse à Dattakumar Chaskar

Re: Panchet & Khadakwasla Dam failure

par Rajesh Gupta,

Please send the link

En réponse à Rajesh Gupta

Re: Panchet & Khadakwasla Dam failure

par Dattakumar Chaskar,

Dear Participants, 

There was some issue with the link I had given in my earlier post. It seem that the video has been removed due to copyright issue.

Dattakumar