Irrigation is a critical component of Bihar's agrarian economy, supporting the livelihoods of a significant portion of its population. The state's geographical, climatic, and hydrological attributes make irrigation management both an opportunity and a challenge. This article provides a detailed overview of the current status, methods, challenges, and future prospects of irrigation in Bihar.
Geographical and Climatic Context
Bihar is located in the eastern part of India, encompassing an area of 94,163 square kilometers. The state is divided into three agro-climatic zones:
North West Alluvial Plain
North East Alluvial Plain
South Bihar Alluvial Plain
The state experiences a subtropical monsoon climate, with significant rainfall during the monsoon season (June to September). However, uneven rainfall distribution necessitates the development of efficient irrigation systems to ensure water availability for agriculture.
Major Sources of Irrigation in Bihar
Bihars irrigation system relies on diverse water sources, including rivers, canals, tube wells, ponds, and traditional methods. Below are the primary sources:
1. Rivers
Bihar is endowed with a rich network of rivers, primarily the Ganges and its tributaries like Gandak, Kosi, Son, and Bagmati. These rivers form the backbone of irrigation infrastructure, supplying water to numerous canal systems.
2. Canal Irrigation
Canals are the most significant irrigation infrastructure in Bihar. The state has an extensive network of canals fed by river systems. Prominent canal systems include:
Gandak Canal System
Sone Canal System
Kosi Canal System
3. Tube Wells and Bore Wells
Groundwater extraction through tube wells and bore wells is a major source of irrigation, especially in areas where surface water is not accessible. The introduction of diesel and electric pumps has boosted groundwater irrigation.
4. Tanks and Ponds
Traditional water bodies like tanks and ponds play a significant role in localized irrigation, especially in drought-prone areas.
5. Traditional Methods
Methods such as Ahars and Pynes are unique to Bihar. These are community-managed irrigation systems that involve:
Ahars: Reservoirs for collecting rainwater.
Pynes: Channels constructed to divert river water to agricultural fields.
Irrigated Area in Bihar
The total irrigated area in Bihar fluctuates annually, depending on rainfall and the operational efficiency of irrigation infrastructure. As per the latest data:
Net irrigated area: Approximately 55% of the total cultivable land.
Source-wise contribution:
Canals: ~33%
Tube wells and bore wells: ~60%
Other sources (tanks, ponds): ~7%
Challenges in Irrigation Development
Despite its potential, Bihar faces several challenges in developing a robust irrigation system:
1. Uneven Distribution of Water Resources
The northern part of Bihar is rich in surface water due to Himalayan rivers, while the southern region depends largely on groundwater. This uneven distribution complicates irrigation planning.
2. Floods and Waterlogging
Bihar is prone to frequent flooding, particularly in the Kosi and Gandak basins. This leads to waterlogging and damages irrigation infrastructure.
3. Poor Maintenance of Infrastructure
Aging canals, siltation, and lack of regular maintenance reduce the efficiency of irrigation systems.
4. Energy Deficiency
Groundwater irrigation heavily depends on electricity or diesel for pumping. Erratic power supply and high diesel costs limit the utilization of tube wells.
5. Climate Change
Changing rainfall patterns and increasing frequency of extreme weather events impact water availability and irrigation schedules.
6. Socioeconomic Barriers
Fragmented landholdings, lack of financial resources, and limited access to technology hinder the adoption of modern irrigation methods.
Government Initiatives for Irrigation Development
The government of Bihar, in collaboration with central agencies, has implemented various schemes to improve irrigation facilities:
1. Jal-Jeevan-Hariyali Abhiyan
This state-level initiative focuses on water conservation, rejuvenation of traditional water bodies, and the development of irrigation infrastructure.
2. Accelerated Irrigation Benefits Programme (AIBP)
Under this central scheme, projects like the restoration of canal systems and modernization of irrigation infrastructure have been undertaken.
3. Pradhan Mantri Krishi Sinchayee Yojana (PMKSY)
PMKSY aims to provide "Har Khet Ko Pani" (water to every farm) by enhancing the efficiency of water use in agriculture.
4. Micro-Irrigation Projects
Subsidies and financial support are provided to promote micro-irrigation techniques like drip and sprinkler systems, especially in water-scarce areas.
Innovative Irrigation Practices in Bihar
To overcome the challenges, Bihar has started adopting innovative irrigation practices:
Micro-Irrigation Systems
Drip and sprinkler irrigation are gaining popularity for their efficiency and water-saving potential.
Conjunctive Use of Water
The simultaneous use of surface and groundwater helps in optimizing water resources.
Solar Pumps
Solar-powered irrigation pumps are being promoted to reduce dependency on conventional energy sources.
Community Irrigation Systems
Reviving Ahars and Pynes under community-based management has improved water access in some regions.
Future Prospects for Irrigation in Bihar
The future of irrigation in Bihar depends on sustainable practices, technological advancements, and effective policy implementation. Key areas for development include:
1. Infrastructure Modernization
Upgrading canals and removing silt to improve water flow.
Building additional check dams and barrages for water storage.
2. Promotion of Micro-Irrigation
Scaling up the adoption of drip and sprinkler systems through subsidies and awareness campaigns.
3. Groundwater Management
Introducing regulatory measures to prevent over-extraction.
Encouraging rainwater harvesting to recharge aquifers.
4. Flood and Drought Management
Implementing comprehensive river basin management plans.
Developing early warning systems for flood-prone areas.
5. Policy Reforms
Strengthening public-private partnerships (PPPs) in irrigation projects.
Introducing financial incentives for farmers adopting efficient irrigation methods.
6. Climate Resilience
Developing climate-resilient infrastructure.
Promoting water-efficient crops and cropping patterns.