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households living in high rise buildings. The results are in conformity with the information that about 75 of the population was affected by the floods of 2006.
Flood damages reported by the respondents include mainly damage to houses, movable assets. The composition of house types across the sample settlements is presented in the Map
Annexure L.
5.9.7 Hydrometeorological risk exposure
Risk from Khadi floods were assessed based on the distance from the stream Khadi. Under the climate change scenarios, the local floods are likely to increase and the population at risk
is presented in the following Table 40.
Table 40: Households at risk from Khadi Floods across SECs based on GIS analysis
Sl. No. Risk type
Slum Lower
Middle Mixed
Grand Total
1 Khadi Medium
40 54
57 54
51 2
Khadi High 60
46 43
46 49
Percentage total 100
100 100
100 100
Total households 18,800
20,959 22,716
8,771 71,246
Source: TARU Primary Study, 2009
About 71,000 households are at risk based on the analysis out of which nearly half are located in the floodplain within 50 m from the stream. The slum and lower SEC groups
comprise 50 of the risk prone households. The actual numbers may be different due to terrain conditions and manmade obstructions to flood discharge. The 2006 Tapti flood
inundation map was used to analyse the households at risk at city level. The results are presented in the following Table 41.
Table 41: Households Across SECs potentially prone to 2006 Flood inundations
GIS analysis
Sl. No. Flood Risk
Slum Lower
Middle Mixed
Upper Grand Total
1 3 feet
19 24
28 37
10 26
2 3-5 feet
27 23
21 37
32 25
3 5-10 feet
21 8
28 17
30 22
4 10 feet
33 46
24 8
28 26
Percentage 100
100 100
100 100
100 Total Households
45,786 82,412
218,471 73,571
37,574 457,814
Source: TARU Field Study, 2009
The middle class is the most affected SEC as per the analysis, even though most of the poor are located along the drainage lines. However, the people living in multistoried apartments
are less likely to be impacts as much as lower and Slum SECs predominantly living in single storied houses. About 75percent of the city population is affected by floods.
The direct risk from sea level rise is only about 5,000 households located along the tidal creeks. The SLR risk prone areas are not populated yet, except for few thousand houses near
Dumas. With the expansion, the SLR risk prone areas, especially along the tidal creeks are expected to grow. A strategy for controlling these risk prone areas from real estate
ACCCRN – City Vulnerability Assessment Report 100
development is necessary to avoid future damage from sea level rise related risks. The measures may include use of these lands for recreation and other uses with minimal
investments on development. Even though structural measures like seawalls may prevent coastal erosion but long term costs and benefits have to be against possible catastrophic
damages from cyclones etc should also be evaluated.
Major modifications in hydrological regime have taken place in Surat and Hazira. Embankments in the city area have constrained the flow within the normal river banks.
Overall Raising of the ground level by more than 3 m in Hazira and closure of tidal creeks that could potentially drain the water further reduced the flood plain. Sea level rise is likely to
further aggravate the free flow of flood waters. The climate change scenarios indicate increase in rainfall by about 100-200 mm of annual rainfall. Also the monsoon rainfall is
expected to be dominated by heavy rain spells separated by longer dry spells. All the above changes can potentially increase the frequency of floods. While near real time weather and
hydrological information based management of Ukai can overcome minor Tapti floods, the competing objectives of the dam irrigation, drinking water, power and partial flood control
cannot avoid the late monsoon floods. With the population increase in the Ukai command area, water demands are only expected to grow.
One of the most important adaptation needs would be to learn to live with the floods, with anticipative planning to reduce the damages. Surat has already taken steps like uninterrupted
water supply even during floods, and aims to harden power supply, communication and other essential services; integrated planning to live with floods will be topmost adaptation agenda
for the city.
5.10 Advanced Warning Mechanisms and Coping Mechanisms
