The largest canal in Uttar Pradesh is the Sharda Canal.

The Sharda Canal is an important irrigation canal that is located in the western part of Uttar Pradesh. It is an inter-state canal that originates from the Sharda River in Uttarakhand and flows through the districts of Pilibhit, Shahjahanpur, Lakhimpur Kheri, and Hardoi in Uttar Pradesh.

Key Points:
- Origin: The Sharda Canal originates from the Sharda River in Uttarakhand. The river is also known as the Mahakali River in Nepal.
- Length: The total length of the Sharda Canal is approximately 269 kilometers, making it the longest canal in Uttar Pradesh.
- Purpose: The primary purpose of the Sharda Canal is to provide irrigation water to the agricultural fields in the region. It plays a crucial role in supporting the agricultural activities in the districts it passes through.
- Canal System: The canal system consists of main canals, distributaries, and minors. The main canal carries water from the river and distributes it to the fields through the network of distributaries and minors.
- Capacity: The canal has a significant water-carrying capacity, which allows it to supply water to a large area for irrigation purposes. It helps in improving agricultural productivity and supports the livelihoods of the farmers in the region.
- Importance: The Sharda Canal is of great importance to the agrarian economy of Uttar Pradesh. It helps in ensuring a regular and reliable water supply to the farmers, which is crucial for their crop cultivation and sustenance.
- Impact: The canal has had a positive impact on the agricultural production in the region. It has led to increased agricultural productivity, improved crop yields, and enhanced rural development.
- Associated Projects: Several other irrigation projects and barrages have been constructed on the Sharda Canal to manage and regulate the water flow. These projects help in maximizing the utilization of water resources and ensuring equitable distribution of water among the farmers.

In conclusion, the Sharda Canal is the largest canal in Uttar Pradesh. It plays a vital role in irrigating agricultural fields and supporting the agrarian economy of the state.