Executive Summary:
This document is the answer given by the Minister of State for Jal Shakti to the Lok Sabha Unstarred Question No. 4639 on August 21, 2025, regarding silt accumulation in rivers. It addresses concerns about silt volume, impact assessment, contributing factors, desilting projects, and their effectiveness in major rivers, particularly in Maharashtra and Madhya Pradesh. The response details studies, approaches to sediment management, and actions taken by state governments.
Key Points / Main Content:
* **Siltation and River Dynamics:**
* Erosion and silt deposition are natural river functions influenced by geological, hydrological, climatic, and anthropogenic factors.
* Rivers maintain a balance between silt load carried and deposited, defining the river regime.
* **Morphological Studies:**
* The Central Water Commission (CWC) conducted morphological studies of 15 major rivers, including the Krishna and Tapi, using remote sensing.
* Krishna River (1973-2011): Total erosion was 47.5 km2, and total deposition was 42.2 km2.
* Tapi River (using 2010 satellite imagery vis-a-vis 1971-79): Erosion and deposition on the left bank were 17.79 km2 and 54.71 km2 respectively; on the right bank, they were 45.96 km2 and 11.63 km2 respectively.
* **Desilting Projects:**
* Dredging/desilting is not considered techno-economically feasible due to sustainability issues and land requirements for disposal.
* The National Framework for Sediment Management (NFSM), published in October 2022, emphasizes reducing silt generation over removal.
* Selective dredging for drainage congestion, channel capacity, and navigation is implemented by states/agencies based on local conditions and scientific studies.
* **State Government Actions:**
* The Government of India provides technical advice and financial assistance for flood management, supplementing state efforts.
* Narmada Valley Development Authority, Madhya Pradesh, has no current desilting projects planned.
* Maharashtra removed 30.25 lakh cubic meters of silt from the Savitri River and tributaries (2022-2023) and 20.38 lakh cubic meters from the Vashishti River via District Disaster Management Authority and Water Resources Department, respectively, which helped control flood situations.
* **Data and Evaluation:**
* Data on funds allocated/spent by states on desilting is not centrally maintained.
* Flood management measures through desilting/dredging are formulated and implemented by state governments based on their priorities.
Impact Analysis:
* **Central Water Commission (CWC):**
* *Impact:* Their morphological studies provide data for understanding river dynamics.
* *Action Required:* Continue monitoring and studying river morphology using remote sensing and other techniques.
* **State Governments (Maharashtra & Madhya Pradesh):**
* *Impact:* Responsible for implementing desilting projects and flood management measures.
* *Action Required:* Formulate and implement selective dredging projects based on local conditions and scientific studies; prioritize reducing silt generation.
* **Department of Water Resources, River Development and Ganga Rejuvenation:**
* *Impact:* Oversees national policy and provides support to state governments.
* *Action Required:* Continue promoting the National Framework for Sediment Management and providing technical and financial assistance to states.
Key Entities Referenced
Ministry of Jal Shakti: The Indian government ministry responsible for water resources.
Godavari River: A major river in Central and Southern India.
Krishna River: A major river in Southern India.
Tapi River: A river in Central India.
Narmada River: A river in Central India.
Maharashtra: A state in western India, mentioned in the context of desilting projects.
Madhya Pradesh: A state in central India, mentioned in the context of desilting projects.
Central Water Commission (CWC): An organization that conducted morphological studies of major rivers.
National Framework for Sediment Management (NFSM): A framework published by the Department of Water Resources, River Development and Ganga Rejuvenation in October 2022.
GOVERNMENT OF INDIA
MINISTRY OF JAL SHAKTI
DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT & GANGA REJUVENATION
LOK SABHA
UNSTARRED QUESTION NO. 4639
ANSWERED ON 21.08.2025
SILT ACCUMULATED IN RIVERS
4639. SHRI SHRIRANG APPA CHANDU BARNE:
SMT. BHARTI PARDHI:
Will the Minister of JAL SHAKTI be pleased to state:
(a) the current estimated volume of silt accumulated in the rivers of Maharashtra, specifically the
Godavari, Krishna, Bhima, Tapi and Narmada during the last decade;
(b) whether the Government has conducted a comprehensive impact assessment of silt accumulation on
the ecological health, water carrying capacity, flood incidence and groundwater recharge of these rivers
and if so, the findings thereof;
(c) the primary anthropogenic and natural factors contributing to increased siltation in these rivers;
(d) the details of the specific desilting projects currently underway or planned for the major rivers in
Maharashtra and Madhya Pradesh along with the timeline fixed and the budget allocated for each
project;
(e) the measured effectiveness of past and ongoing desilting operations in terms of increasing river
capacity, reducing flood risk and improving riverine ecosystems; and
(f) whether any independent evaluations of the said projects have been conducted and if so, the details
thereof?
ANSWER
THE MINISTER OF STATE FOR JAL SHAKTI
(SHRI RAJ BHUSHAN CHOUDHARY)
(a) to (c) Erosion and deposition of silt in a river are natural regulating functions of a river. This is
caused by various natural geological, geo-morphological, hydrologic, climatic factors like floods, inflow
of sediment from the drainage basin, heavy rainfall and anthropogenic activities, etc. They define the
river morphology which continues to change over time. Rivers tend to maintain a balance between the
silt load carried and silt load deposited, maintaining a river regime.
Morphological studies of 15 major rivers have been conducted by Central Water Commission
(CWC) using remote sensing technique which includes Krishna and Tapi among others. The study of
Krishna river is based on the data for the period 1973 - 2011, indicating total erosion of both the banks
of Krishna river as 47.5 km2 (left bank 21.9 km2 and right bank 25.6 km2) and total deposition of 42.2
km2 (left bank 24.2 km2 and right bank 18 km2). The study of Tapi river has indicated erosion and
1deposition of 17.79 km2 and 54.71 km2 respectively on the left bank and erosion and deposition of 45.96
km2 and 11.63 km2 respectively on right bank of Tapi River considering 2010 satellite imagery data vis a
vis bank line for the year 1971-79.
(d) to (f) Dredging/desilting of rivers is not considered techno-economic feasible due to several reasons
like non-sustainability, non-availability of vast land required for the disposal of dredged material, etc.
National Framework for Sediment Management (NFSM) has been published in October, 2022 by
Department of Water Resources, River Development and Ganga Rejuvenation. It emphasises on
reducing silt generation rather than silt removal and promotes technological innovations & best
practices. The framework lays emphasis on sediment management through integrated river basin
management plan giving due consideration to environment and ecology. Selective 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 based upon local site conditions
and backed by proper scientific model study.
Data on funds allocated/spent by States on desilting of rivers is not maintained centrally. The
measures of desilting/dredging of rivers for flood management are formulated and implemented by the
State Governments as per their priority. The Government of India supplements the efforts of State
Governments by providing technical advice and promotional financial assistance for flood management
in critical areas.
Narmada Valley Development Authority, Government of Madhya Pradesh, has informed that they
have not planned any desilting project presently.
Water Resources Department, Government of Maharashtra has informed that removal of silt from
Savitri river and its tributaries were undertaken through District Disaster Management Authority in the
year 2022 and 2023 and approximately 30.25 lakh cubic meter of silt was removed. Also, 20.38 lakh
cum of slit was removed from Vashishti river, Tal. Chiplun by Water Resources Department of
Maharashtra State with the help of local Government bodies. Due to these river de-silting works, the
flood situation has been controlled to considerable extent.
*****
2