New Dams and Reservoirs in Sri Lanka

Project Overview

This project presents a comprehensive GIS-based map of new, existing, under-construction, and proposed dams and reservoirs across Sri Lanka. The mapping integrates construction status, managing organisations, river basins, and reservoir capacity to support national water resources planning and decision-making.

Study Area

The study covers the entire island of Sri Lanka, encompassing all major river basins including Mahaweli, Kelani, Walawe, Kala Oya, Gal Oya, Deduru Oya, Malwathu Oya, and several regional and coastal catchments.

Data Sources

National dam and reservoir inventory – Irrigation Department
River basin boundaries – Irrigation Department
Administrative boundary of Sri Lanka – Survey Department
Institutional data (ID, MASL, CEB, NWSDB, NPC)
Reservoir capacity, construction year, and status records

Methodology

Compilation and validation of national dam and reservoir datasets
Standardisation of attribute information (status, organisation, basin)
Classification of reservoirs by development status (completed, under construction, pending, design ongoing)
River basin-wise spatial analysis
Professional cartographic symbolisation and map layout design

New Dams and Reservoirs Map of Sri Lanka

New Dams and Reservoirs in Sri Lanka Map

The map illustrates the spatial distribution of dams and reservoirs across Sri Lanka, classified by construction status and managing organisation, and overlaid with major river basins to highlight hydrological significance.

List of New Dams and Reservoirs

The attribute table summarises key information including reservoir name, construction year, managing organisation, river basin, storage capacity, and current development status.

Key Observations

The Mahaweli River Basin contains the highest number of large-scale reservoirs
Most newly proposed reservoirs are concentrated in dry zone river basins
Multiple institutions contribute to national water infrastructure development
Several projects are currently under construction or pending funding as of 2025

Tools & Skills

ArcGIS Pro
Spatial database management
National-scale hydrological mapping
Cartographic design and layout preparation
Data validation and standardisation

Conclusion

This project strengthened practical skills in large-scale GIS mapping, hydrological data integration, and professional cartographic presentation. The final outputs support national water resource planning and reflect real-world GIS work conducted during my internship at the Irrigation Department.