Lok Sabha Question No. 112 (STARRED), answered on 2023-07-27
Subject: Soil Erosion due to Floods in Assam
Ministry: JAL SHAKTI
Asked by: Naba (Hira) Kumar Sarania

## GOVERNMENT OF INDIA

## MINISTRY OF JAL SHAKTI DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION

## LOK SABHA STARRED QUESTION NO. *112

ANSWERED ON 27.07.2023

## SOIL EROSION DUE TO FLOODS IN ASSAM

## † *112 SHRI NABA KUMAR SARANIA

Will the Minister of JAL SHAKTI be pleased to state:

- (a) whether any corrective steps have been taken to check the soil erosion in the rivers caused by heavy rains and consequential floods in the lower lying areas of Assam and if so, the details thereof;
- (b) whether the Government proposes to construct concrete embankments after dredging of the rivers; (c) if so, the details thereof; and
- (d) the details of various schemes being implemented for the flood management and erosion control in rivers and rivulets of Assam and North- Eastern States?

## ANSWER

## THE MINISTER OF STATE FOR JAL SHAKTI

( SHRI BISHWESWAR TUDU )

- (a) to (d) : A statement is laid on the Table of the House.

## STATEMENT REFERRED TO IN REPLY TO PARTS (a) TO (d) OF LOK SABHA STARRED QUESTION  NO.  *112  TO  BE  ANSWERED  ON  27.07.2023  REGARDING  'SOIL  EROSION DUE TO FLOODS IN ASSAM'.

(a) Erosion, movement 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. Soil erosion caused by heavy floods is a matter of concern as it leads to several associated problems like changes in river course, loss of land, etc. Flood management, including erosion control, falls within the purview of the States. Flood management and anti-erosion schemes are formulated and implemented by concerned State Governments as per their priority. The Union Government supplements the efforts  of  the  States  by  providing  technical  guidance  and  also  promotional  financial assistance  for  management  of  floods  in  critical  areas.  The  Government  of  India  has  been  making continuous efforts to assist the State Governments in effective flood management and erosion control. Morphological studies using remote sensing technique by various IITs and NIIT have been carried out for major rivers, including Brahmaputra river. These studies play an important role in understanding the nature of rivers  in  a  comprehensive  manner  and  provide assessment of decadal bank-line movement, erosion and  deposition in different reaches in respect of base year, derivation of  reach-wise morphological  indices  and  identification  of  critical  reaches.  These  studies  have  been  shared  with concerned  State  Governments  and  other  stakeholders  etc.  for  taking  informed  decision  and  future planning. As  per the  morphological study of Brahmaputra  river conducted  by  Central  Water Commission  (CWC)  through  consultancy  from  IIT  Guwahati,  it  has  been  estimated  that  in  the Brahmaputra river a total erosion of 252.6 sq. km. and deposition of 118.6 sq. km. occurred between 2003-05 and 2008-11.

As informed by Water Resources Department, Government of Assam, around 1,170 bank protection works with geo-materials, concrete slabs/blocks, boulders, etc. have been implemented in order to check the soil erosion in the rivers and rivulets caused by heavy rains and consequential floods in the lower lying areas of the State.

(b) & (c) Dredging/desilting of rivers is not considered a technically viable solution for flood control as it can marginally minimize the magnitude of floods 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 study.

The  Ministry  of  Jal  Shakti  has  formulated  a  'National  Framework  for  Sediment  Management (October  2022)'  for  managing  sediments  in  a  holistic  manner.  This  framework  lays  emphasis  on sediment management through integrated river basin management plan.

Embankments  are  generally  considered  as  economical,  quick  and  most  popular  method  of  flood protection and have been constructed extensively in the past. Embankments (including ring bunds and town  protection  works)  confine  the  flood  flows  and  prevent  spilling,  thereby  reducing  the  damage. Depending upon local site conditions, availability of material and other technical considerations various types  of  embankments  /flood  walls  viz.,  earthen,  masonry,  concrete,  etc.  are  constructed.  However, construction of embankments is to be carried out after proper scientific, morphological and modelling studies  of  river  for  identifying  changes  in  river  courses,  vulnerable  locations,  rise  in  afflux  due  to jacketing  etc.  Union  Government  currently  has  no  plan  to  construct  concrete  embankments  after dredging the rivers.

(d) To strengthen the structural measures of flood management, Union Government had implemented Flood Management Programme (FMP) during XI & XII Plan for providing central assistance to States for works related to flood management, anti-erosion, drainage development, anti-sea erosion, etc. which subsequently  continued  as  a  component  of  "Flood  Management  and  Border  Areas  Programme" (FMBAP) for the period from 2017-18 to 2000-21 and was further extended up to September 2022 with limited  outlay.  So  far,  central  assistance  amounting  to  Rs.  2,186.63  crore  has  been  released  to  North Eastern States under FMP component of this programme since inception with details at Annexure .  In addition, Brahmaputra Board has implemented flood management works of protection of 'Majuli Island from  flood  and  erosion'  and  'Avulsion  of  Dholla  Hatighuli  Phase  V'  with  an  estimated  cost  of  Rs. 233.57 crore and Rs. 24.95 crore, respectively. Government of India also provides technical support to States  for  undertaking  flood  control  projects  through  financial  assistance  from  multilateral  funding agencies.

***

ANNEXURE REFERRED TO IN REPLY TO PART (d) OF STARRED QUESTION NO. *112 TO BE ANSWERED IN LOK SABHA ON 27.07.2023 REGARDING 'SOIL EROSION DUE TO FLOODS IN ASSAM'.

## Details of Projects implemented in North-Eastern States under FMBAP Scheme

| Sl. No.   | State/ UT         |   No. | Total Cost (Rs crore)   | Funds Released (Rs crore)   |   Works completed | Area benefited (ha)   | Population benefited (number)   |
|-----------|-------------------|-------|-------------------------|-----------------------------|-------------------|-----------------------|---------------------------------|
| 1         | Arunachal Pradesh |    21 | 224.69                  | 190.78                      |                21 | 47,617                | 2,01,209                        |
| 2         | Assam             |   142 | 2499.1                  | 1,549.83                    |               141 | 7,21,019              | 177,12,497                      |
| 3         | Manipur           |    23 | 569.76                  | 219.71                      |                23 | 39,315                | 2,01,640                        |
| 4         | Mizoram           |     2 | 9.13                    | 16.89                       |                 2 | 136                   | 312                             |
| 5         | Nagaland          |    17 | 123.87                  | 93.96                       |                14 | 2,463                 | 1,63,000                        |
| 6         | Sikkim            |    45 | 366.32                  | 91.84                       |                45 | 48,728                | 2,06,534                        |
| 7         | Tripura           |    11 | 26.57                   | 23.62                       |                11 | 1,964                 | 88,480                          |
|           | Total             |   261 | 3,819.4                 | 2,186.63                    |               257 | 8,61,242              | 185,73,672                      |

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