The Mannakkattiya – Eruwewa – Mahakanadarawa Irrigation System is a significant agricultural water management project in Sri Lanka, designed to enhance water distribution and irrigation in the North Central Province. This system is part of a broader effort to improve water availability for agriculture and domestic use in the region, which is crucial for sustaining the livelihoods of local communities and boosting agricultural productivity.

Project Overview

• Location: The irrigation system spans several key reservoirs in the North Central Province, including Mannakkattiya, Eruwewa, and Mahakanadarawa. These reservoirs are strategically interconnected to optimize water flow and distribution across the region.
• Purpose: The main objective of the irrigation system is to transfer and distribute water from the Moragahakanda Reservoir via the Upper Elahera Canal (UEC) to these reservoirs, ensuring a reliable water supply for irrigation and other uses.

Irrigation System Components

1. Mannakkattiya Reservoir:
   • This reservoir serves as a primary point for receiving water from the UEC. It acts as a central hub in the irrigation system, distributing water to downstream reservoirs and canals.
2. Eruwewa Reservoir:
   • Located downstream of Mannakkattiya, Eruwewa receives water that is further distributed to agricultural lands in the area. This reservoir plays a crucial role in maintaining water levels for irrigation, especially during the dry season.
3. Mahakanadarawa Reservoir:
• This is one of the final points in the irrigation system, where water is distributed to the surrounding farmlands. Mahakanadarawa is essential for ensuring that the farmlands in the region receive adequate water throughout the year.

Water Management and Distribution

The irrigation system is designed to handle a significant volume of water, with the MCB (Mahaweli Consultancy Bureau) studies indicating that 281 million cubic meters (MCM) of water is intended to be transferred through the Mannakkattiya outlet. This water is further distributed with 155 MCM allocated to the Mannakkattiya-Eruwewa-Mahakanadarawa chain and 126 MCM to the Huruluwewa system.

The efficient management of this water is critical for increasing the cropping intensity in the region, with the goal of raising it from 1.2 to 1.8, meaning that farmers will be able to cultivate their lands more frequently, thereby increasing agricultural yields.

Challenges and Considerations

• Water Allocation: With limited water resources, careful planning is required to ensure that the water is allocated effectively to meet both agricultural and domestic needs.
• Infrastructure Development: The success of this irrigation system depends heavily on the completion and maintenance of the necessary infrastructure, including the UEC and the various canals and reservoirs involved in the system.
• Environmental Impact: The project must also consider the environmental impacts of diverting and distributing large volumes of water, ensuring that the local ecosystems are preserved while meeting human needs.

MCB’s Role

The Mahaweli Consultancy Bureau (MCB) was deeply involved in the planning and design of the Mannakkattiya – Eruwewa – Mahakanadarawa Irrigation System. Their role included conducting detailed studies and preparing Environmental Impact Assessments (EIA) to ensure that the project was sustainable and aligned with environmental standards. The MCB’s expertise in water resource management was crucial in designing a system that maximizes water use efficiency while minimizing adverse impacts on the environment.