Lok Sabha Question No. 2940 (UNSTARRED), answered on 2024-12-12
Subject: Koshi River in Bihar
Ministry: JAL SHAKTI
Asked by: Shri Dinesh Chandra Yadav

## GOVERNMENT OF INDIA MINISTRY OF JAL SHAKTI

## DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION

## LOK SABHA UNSTARRED QUESTION NO. 2940

ANSWERED ON 12.12.2024

## KOSHI RIVER IN BIHAR

## †2940. SHRI DINESH CHANDRA YADAV

Will the Minister of JAL SHAKTI be pleased to state:

(a)  whether  it  is  a  fact  that  the  new  embankments  built  on  both  sides  of  the  Koshi  river  in  Bihar  are adversely affecting the stability of the river even though its capacity to carry nine lakh cusecs of water and if so, the details thereof;

(b) whether the release of excess water in Koshi river from Nepal causes devastating flood in the coastal areas of Koshi and in Madhepura, Saharsa and Khagaria districts and if so, the details thereof;

(c) whether it is a fact that river bed of Koshi river is getting overflowed due to the high amount of sand and silt in the water released from Nepal during rainy season which is the main cause of floods; and

(d)  if  so,  whether  the  Government  contemplates  any  scheme  for  desilting  the  river  bed  of  Koshi  to remove the recently deposited silt and if so, the details thereof?

## ANSWER

## THE MINISTER OF STATE FOR JAL SHAKTI

## ( SHRI RAJ BHUSHAN CHOUDHARY )

(a) The Kosi River barrage, along with its associated structures and levees/embankments, was originally designed to handle a peak discharge of 9.5 lakh cusecs. The construction of embankment on both sides of the Kosi river in Bihar are not adversely affecting the stability of the river.

(b) Heavy  rainfall  in  the  upper  catchment  areas  of  Kosi  river,  which  mainly  lie  in  Nepal,  causes increased discharge in the river and is one of the main reason for floods in Supaul, Madhepura, Saharsa, Katihar  and  Khagaria  districts  of  the  State  of  Bihar.  Each  year,  this  region  faces  flooding  in  varying degrees.

(c) & (d) Erosion and deposition of sediment in a river are natural regulating functions of a river. Rivers tend  to  maintain  a  balance  between  the  silt  load  carried  and  silt  load  deposited,  maintaining  a  river regime.  Dredging/desilting  of  rivers  is  not  considered  techno-economic  feasible  solution  to  mitigate floods as it can provide benefits marginally and is effective only for a short period. Selective dredging in specific reaches such as tidal rivers, confluence points with narrow constrictions, etc., sometimes may

have to be undertaken based upon local site conditions. However, the same should be backed by proper scientific model study.

The desilting measures including dredging in specific reaches of rivers for removal of drainage congestion, channel capacity improvement and navigation purpose are formulated and implemented by concerned  States/agencies  as  per  requirement. As  of  date,  no  proposal  for  cleaning  of  silt  has  been received from the State Govt.

For  the  comprehensive  and  holistic  management  of  sediments  in  a  holistic  manner,  the Department of Water Resources, River Development & Ganga Rejuvenation, Ministry of Jal Shakti, in extensive consultations with Central Government Ministries/ Departments/ State Governments/UTs have prepared the 'National Framework for Sediment Management' (NFSM). Its emphasis is on reducing silt generation  rather  than  silt  removal  and  promote  technological  innovations  &  best  practices. The framework  lays  emphasis  on  sediment  management  through  integrated  river  basin  management  plan giving due consideration to environment and ecology.

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