WHEN WHY? - History of looding in Surat and the reasons TYPES OF FLOODS IN SURAT- loods due to the Ukai dam the Khadi
CONTENTS
IMPACT
I PHYSICAL ENVIRONMENTAL I SOCIAL I ECONOMIC
CHANGE ASSESSMENT
STRATEGY
WATER-
Water supply. SanitaionWaste water. Flood Management I LANDUSE PLANNING I WASTE I COMMUNICATION
1. When Why? History of looding in surat and the reasons 2. Types of loods- loods due to the Ukai dam the Khadi Floods
3. Impact of Urbanizaion, Poverty, Climate change 4. Public percepions
5. Reported Losses
1. WHEN WHY? - History of looding in Surat and the reasons
Since 1869 up to 1884, on an average, the city was looded every two and half years followed by a fall in its frequency by 1914. During 1949 to 1979, the average natural lood occurrence was once in every four years.
The 1968 lood had been the biggest lood witnessed so far and had a highest low of about 42,475 cumecs 1.5 million cusecs. Water level at Hope Bridge, Surat reached 12.01 m.
With this in mind, the Ukai dam, located about 100 km upstream of Surat, was completed in 1972. The major purposes of the dam being essenially irrigaion, power generaion and parial lood control. However, heavy
Rainfall in the catchment area of Ukai Dam in the upstream mainly in Maharashtra which leads to heavy inlow in the Ukai Dam has oten resulted in heavy discharge of water from the Ukai Dam, responsible for looding in
Surat in the past 20 years. This is largely caused by the compeing objecives of the Ukai dam, which designed mainly for irrigaion and power generaion with parial lood control. To meet the irst two objecives, the dam
has to be able to hold as much water as possible leaving a limited cushion for lood control, especially during the later parts of the monsoon.
The loods of 1998, 2004 and 2006 occurred following emergency discharges from Ukai dam. Out of these years, loods of August 2006 remained devastaing for Surat in terms of the extent of damage, during which
nearly 75 of the city was inundated. Anthropogenic changes including building of bridges, embankments and the Singanpore weir have reportedly increased the siltaion and reduced the carrying capacity of the river
channel, as evident from the increasing lood levels for the similar amount of the discharge over last few decades Flood Risk Management Study, Centre for Social Studies. 2009