Eight districts are affected due to heavy rainfall and the resultant flood waters
of Krishna and Tungabhadra rivers. The districts with number of mandals are
Kurnool (25 mandals)
Mahabubnagar (10 Mandals)
Nalgonda (8 mandals)
Krishna (18 mandals)
Guntur (18 mandals)
Kadapa (15 mandals)
Prakasam (2 mandals)
Ranga Reddy (5 mandals)
Part of Kadapa district which is out side the Krishna river basin was affected
due to overflow/diversion of flood waters into Kunderu river through
Potireddipadu head regulator, K.C. Canal,
In all the eight districts 571 villages are affected.
Total population affected is 17.5 lakhs
Number of dams / barrages on Krishna river in Andhra Pradesh : Five
Main inflows to Priyadarshini Jurala Dam (located in Mahabubnagar
district) are from Narayanpur dam (Karnataka State)
Inflows to Srisailam dam is from Krishna ( Priyadarshini Jurala) and
Tungabhadra (Sunkesula anicut) rivers.
The observed peak inflows (cusecs) at major dams / barrages are as
Srisailam : Maximum peak inflow : 25 lakhs c/s (30.09.09)
Nagarjunasagar : Maximum peak inflow : 14.66 lakhs c/s(3.10.09)
Prakasam Barrage : Maximum peak inflow : 11.03 lakhs c/s (6.10.09)
Rise in inflows and outflows at Priyadarshini Jurala are
observed from 30.9.2009 to 03.10.2009.
Rise in inflows at Srisailam dam are observed from 30-9-2009
to 03-10-2009 and outflows from 30-09-2009 to 04-10-2009.
Rise in inflows in Nagarjunasagar Dam is observed on
30.9.2009 and rise in outflows started on 1.10.2009. The
maximum inflow and outflow is observed on 05.10.2009.
In case of Prakasam barrage rise in inflows and outflows
started on 2.10.2009 and continued till 06.10.2009.
Kurnool, the district headquarters is located near the
confluence of Tungabhadra and Handri rivers. The river Handri
and Kurnool-Kadapa canal passes through the Kurnool town.
The level of inundation in Kurnool town is extended upto
about 902 ft contour against 885 ft FRL at Srisailam dam.
The maximum extent of flooding occurred along Tungabhadra
and Handri rivers inundating Kurnool town which is due to :
a) Back water effect upto or slightly above 902 ft.
b) Inflows of more than 2 lakh cusecs from Handri river
FLOOD AFFECTED AREA IN AND AROUND MANTRALAYAM
Alampur, a pilgrim centre, located in
Mahabubnagar district adjacent to
Tungabhadra river is highly damaged.
The level of inundation in Alampur town is
extended upto about 902 ft contour against
885 ft FRL at Srisailam dam.
The back waters of Srisailam dam released from
Potireddipadu Head Regulator, KC Canal and Telugu
Ganga canals, to the tune of above 2 lakh cusecs came
into Kunderu river and caused flooding in Nandyal town
(Kurnool district) and the down stream villages before
joining Pennar River.
Due to floods in Kunderu river 5 mandals in Kurnool
district and 5 mandals in Kadapa district are affected.
The extent of inundation is observed between 200m
(Kunderu river bed level) and 205m contours in Nandyal
town which is located along Kunderu river.
Various flood scenarios have been developed for
the release of 10 lakh, 12 lakh, & 14 lakh cusecs of
water at NSP using MIKE II hydrodynamic model.
The flood scenario developed for the discharge of
12 lakh c/s at Nagarjunasagar project is close to
to the ground reality.
The likely flooding areas in the down stream of
Nagarjuna Sagar Dam shows 13 mandals in
Guntur district and 16 mandals in Krishna district .
The flood hazard map of Krishna and Guntur
districts is prepared (early 1990s) based on geo-
morphology, historical flood data, extensive
ground truth information etc.
The hazard map is superimposed with 1-5 km
buffer zones (one km interval) along Krishna
The list of villages located in each one km buffer
zone, which are in highly flood prone areas, are
provided to the Government for relief operations
two days ahead of the deluge.
A breach in the flood bank of Krishna river is observed at
Oleru village, Bhattiprolu mandal, Guntur district on
Probable flood scenarios due to the breach were
developed using flood models, elevation data, drainage,
flood hazard maps and field experience.
The probable flood affected habitations (22no.) were
mapped and communicated to government for
evacuation and relief operations on 06.10.09.
The flood layer generated by NRSC using RISAT II
(6.10.09) and RADARSAT (7.10.2009) data clearly
confirmed that the habitations that were given on 6.10.09
are affected. 29
No. of villages in Nalgonda district : 85
No. of villages in Guntur district : 131
No. of villages in Khammam district: 14
No. of villages in Krishna district : 154
No. of villages in Guntur district : 191
No. of villages in Krishna district : 422
No. of villages in West Godavari district : 19
No. of villages in Nalgonda district : 10
No. of villages in Prakasam district : 1
No. of villages in Guntur district : 1
No. of villages in Kurnool district : 33
No. of villages in Mahabubnagar district : 60
Dam break analysis is attempted to map the
probable inundation areas in the down stream
of dams / barrage.
This analysis is made based on volume of
inflow / outflow, characteristics of each dam,
contour, drainage, slope and historical data.
The extent of land use / land cover classes
likely to be damaged in the event of dam break
is also mapped.