Uttar Pradesh, being a predominantly agrarian state, has historically relied heavily on irrigation for its agricultural productivity. Over time, the sources and methods of irrigation in the state have undergone significant, albeit gradual, transformations. These changes reflect technological advancements, policy interventions, and evolving agricultural needs.

Historical Context: Traditionally, irrigation in Uttar Pradesh was dominated by:

• Wells: Manual or animal-powered wells were a primary source, especially for small landholdings.
• Tanks/Ponds: Natural and man-made tanks collected rainwater and served as local irrigation sources.
• Small Canals: Localized canal systems, often fed by rivers, existed but were limited in reach.

Changes Post-British Era and Post-Independence:

1. Expansion and Modernization of Canal Systems: The British initiated the construction of major canal networks (e.g., Upper Ganga Canal, Lower Ganga Canal, Eastern Yamuna Canal) primarily for revenue generation and famine relief. Post-independence, there was a continued focus on expanding and modernizing these systems. Canals remain a significant source of irrigation, particularly in the western and central parts of UP, providing surface water to large agricultural tracts. Efforts are now on improving canal efficiency, reducing water loss, and ensuring equitable distribution.

2. Dominance of Groundwater (Wells and Tubewells): This represents the most profound change. The advent of the Green Revolution in the 1960s and 70s, coupled with the availability of electricity and diesel pumps, led to a rapid proliferation of private and public tubewells. Tubewells offer farmers greater control over water supply, allowing them to irrigate precisely when and where needed, independent of canal schedules or rainfall. Consequently, groundwater extraction through tubewells has become the single largest source of irrigation in UP, accounting for a majority of the irrigated area.

3. Decline of Traditional Tanks and Ponds: With the rise of canals and especially tubewells, traditional tanks and ponds have gradually declined in importance. Many have fallen into disuse, been encroached upon, or suffered from neglect, leading to a loss of their water storage capacity. However, there is a growing recognition of their ecological and hydrological value, leading to some efforts for their revival.

4. Emergence of Lift Irrigation Schemes: In areas where canal irrigation is not feasible due to topography, lift irrigation schemes have been developed. These involve lifting water from rivers or canals to higher elevations for distribution to fields. While not as widespread as tubewells, they play a crucial role in specific regions.

5. Focus on Micro-Irrigation (Recent Trend): In response to concerns about groundwater depletion and water use efficiency, there is a gradual shift towards modern micro-irrigation techniques like drip and sprinkler irrigation. Government schemes like the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) promote 'more crop per drop,' encouraging farmers to adopt these water-saving methods, though their adoption rate is still relatively low compared to traditional methods.

6. Rainwater Harvesting and Watershed Development: While not a primary source for large-scale agriculture, there's a growing emphasis on rainwater harvesting and watershed development, particularly in drought-prone regions, to recharge groundwater and improve water availability.

In summary, the irrigation landscape in Uttar Pradesh has gradually transitioned from a reliance on traditional wells and tanks to a dominant dependence on groundwater extracted through tubewells, complemented by an extensive canal network. The current trend is towards improving efficiency, promoting micro-irrigation, and addressing the challenges of groundwater depletion to ensure sustainable agricultural practices.