FOR OFFICIAL USE ONLY भारत सरकार / Government of India कᴂ द्रीय जल आयोग /Central Water Commission Rajahmundry Railway Bridge on river Godavari बा褼 पू셍ाानुमान मूल्ा車कन रिपो셍ा गोदा셍िी बेसिन-2018 Flood Forecasting Appraisal Report G o d a v a r i Basin-201 8 ननचली गोदा셍िी म車डल/ Lower Godavari Division गोदा셍िी परिम車डल/ Godavari Circle हैदिाबाद/ Hyderabad Index FOREWORD .......................................................................................................................................... i Chapter-1 ............................................................................................................................................... 1 River Godavari and its Flood Problem ................................................................................................ 1 1.1 Godavari River System ......................................................................................................... 1 1.2 Physiography of the Basin ................................................................................................... 2 1.3 Rainfall Pattern ..................................................................................................................... 3 1.4 Flood problem: ...................................................................................................................... 4 1.5 Importance of Flood Forecasting in Godavari Basin ......................................................... 5 Chapter-2 ............................................................................................................................................... 6 Flood Forecasting Activities in Godavari Basin ................................................................................. 6 2.1 Flood Forecasting Activity ................................................................................................... 6 2.2 Present Organisational Setup .............................................................................................. 6 2.3 Data Collection Network ........................................................................................................ 6 2.4 Methodology adopted for Flood Forecast Formulation ....................................................... 7 2.4.1 Simple Correlation .......................................................................................................... 7 2.4.2 Multiple Correlation ........................................................................................................ 9 2.4.3 Travel Time Curve ......................................................................................................... 11 2.5 Dissemination of Forecasts .................................................................................................. 11 Chapter-3 ............................................................................................................................................. 13 Southwest Monsoon 2018 .................................................................................................................. 13 3.1 Advancement of Southwest Monsoon 2018 ....................................................................... 13 3.2 Rainfall in Monsoon 2018 .................................................................................................... 13 3.3 Flood events during the flood season 2018 ........................................................................ 14 3.4 Withdrawal of Southwest Monsoon 2018 ......................................................................... 15 Chapter-4 ............................................................................................................................................. 16 Floods Events in Godavari Basin-2018 ............................................................................................. 16 4.1 General ................................................................................................................................. 16 4.2 Floods in Upper Reaches of Godavari Basin ........................................................................ 16 4.2.1 Flood Wave on Godavari at Kopergaon ........................................................................ 16 4.2.2 Flood Wave at Jaikwadi Dam ........................................................................................ 16 4.2.3 Flood wave on Godavari at Gangakhed: ....................................................................... 17 4.2.4 Flood wave on Godavari at Nanded:............................................................................. 17 4.2.5 Flood Wave at Sri Ramsagar Project ............................................................................. 18 4.3 Floods in Manjira Basin ........................................................................................................ 19 4.3.1 Flood Wave at Singur Dam ............................................................................................ 19 4.3.2 Flood Wave at Nizamsagar Dam ................................................................................... 19 4.4 Floods in Wainganga Basin .................................................................................................. 20 4.4.1 Flood Wave at Bhandara ............................................................................................... 20 4.4.2 Flood Wave at Pauni ..................................................................................................... 20 4.5 Floods in Wardha Basin ...................................................................................................... 21 4.5.1 Flood Wave at Balharsha .............................................................................................. 21 4.6 Floods in Indrāvati Basin ..................................................................................................... 21 4.6.1 Flood Wave at Jagdalpur ............................................................................................... 21 4.7 Floods in Lower Reaches of Godavari Basin .................................................................... 22 4.7.1 Flood Wave on Godavari at Kaleswaram ...................................................................... 22 4.7.2 Flood Wave at Eturunagaram ....................................................................................... 23 4.7.3 Flood Wave at Dummugudem ...................................................................................... 23 4.7.4 Flood Wave at Bhadrachalam ....................................................................................... 24 4.7.5 Flood Wave at Kunavaram ............................................................................................ 26 4.7.6 Flood Wave at Rajahmundry ......................................................................................... 26 4.7.7 Flood wave at Dowlaiswaram ....................................................................................... 27 4.8 Details of Peak Levels at Various Forecast Stations ............................................................ 28 4.9 High Flood Situations during Monsoon 2018 ...................................................................... 28 Chapter-5 ............................................................................................................................................. 29 Forecast Performance in 2018 and its Improvements and Modernisation .................................. 29 5.1 Forecast Performance ......................................................................................................... 29 5.2 Improvements to Flood Forecasting ................................................................................. 31 5.3 Modernisation of Flood Forecasting System...................................................................... 31 5.4 Use of Internet in Flood Forecasting ................................................................................... 32 5.5 Three day’s Advance Forecast online model ....................................................................... 32 5.6 Difficulties and Bottlenecks in flood forecasting ................................................................ 32 5.7 Hourly Gauge Variation above Warning Level during Flood Waves .................................. 32 5.8 Suggestions for improvement .............................................................................................. 33 5.9 Future Proposals ................................................................................................................... 33 Statements ........................................................................................................................................... 34 Annexures ............................................................................................................................................ 52 Chapter-1 River Godavari and its Flood Problem 1.1 Godavari River System The Godavari basin lies in the Deccan Plateau and is situated between 16o16’ N and 22o43’ N Latitude and 73o26’ E and 83o07’ E Longitude. It is roughly triangular in shape and the main river itself runs practically along the base of the triangle. The river Godavari, the largest of the peninsular rivers, and the third largest in India, drains about 10% of India’s total geographical area. The catchment area of the river is 3,12,812 sq. km and is spread in the states of Maharashtra (48.6%), Telangana (18.5%), Andhra Pradesh(4.9%), Madhya Pradesh (10%), Chhattisgarh (10.9%),