DAM BREAK ANALYSIS
AND EMERGENCY PREPAREDNESS PLAN OF SRINAGARIND DAM
Pakorn KIJSOMPORN
Head of Dam and Reservoir Engineering Section, Dam Safety Department,
Civil Maintenance Division, EGAT
THAILAND
ABSTRACT
Srinagarind Dam is a multipurpose dam with 140 meter high and 17,745
million cubic meter storage volume, the biggest storage volume of dam in
Thailand. The dam is situated in seismically inactive zone about 200 kilometers
in the west of Bangkok, the capital of Thailand.
Electricity Generating Authority of Thailand (EGAT), as the dam owner,
analyzed and simulated dam break in the year 1992 and 2005 to produce an
inundation map and evacuation area for public safety at downstream of the dam.
In order to get information of the maximum potential of household and loss of
live to be affected, the type of dam failure chosen in both simulations was dam
crest overtopping by incoming of an overdesigned inflow into the reservoir fully
impounded. Breach parameters given from the breach model are 255 meter
breach bottom width, 1:1 breach side slope and 3 hour formation time. Breach
peak outflow of 115,094 cubic meters per second was routed along the
Khwae Yai and Maeklong River using dynamic flood routing of BOSS DAMBRK,
the well known dam break simulation software. Flood wave travelling time to the
end of flooding area at Tha Maka District, 93 kilometers away from the dam, is
21 hours 45 minutes.
Three districts in Kanchanaburi province including city downtown are in
flooding area. The inundation map as well as useful information of the flowing
water from dam failure; list of villages in an inundated area, distance from the
dam, flood wave arriving time, time to maximum stage and evacuation areas
have been distributed to the local and central government offices that are
responsible for emergency situation in the area. Eventually an emergency
preparedness plan, the end result of dam break analysis, was also distributed to
dam regional office to make an emergency action plan.
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