Sri Lanka Lakes, Reservoirs & Tanks Map

How to read the water-body map

Search for a familiar name or select a shape on the map. Small water bodies also have a marker so you can find them at island scale. Open the details to read the place's names, locality and source notes. Choose Whole island to return to the country view.

On a phone, tap a water body to preview its name, then choose the arrow for details. Drag to move the map and pinch with two fingers to zoom. A laptop touchpad also supports pinch zoom; focus the map before using ordinary scrolling to zoom. The +, − and Whole island buttons offer another way to explore.

The optional Major cities layer provides reference points. It starts switched off. Zoom in to explore a shoreline, and compare two places at a similar zoom before describing their shapes.

Lakes, reservoirs and tanks in Sri Lanka

The words lake, reservoir, tank, wewa and kulam appear in familiar place names. They are not five mutually exclusive scientific categories. A tank can store water as a reservoir, and the word “lake” alone does not establish a natural origin. Check the individual source notes before making claims about construction, age or purpose.

Water storage connects places

Water stored in reservoirs can support several uses. The Ceylon Electricity Board describes how reservoirs in the Mahaweli system supply irrigation and other uses as well as electricity generation. Its hydropower guide also explains how Castlereagh and Maussakelle reservoirs feed the Laxapana power-station system. Read CEB's hydropower guide.

Try comparing an urban lake with a reservoir in the central hills. Describe their positions and mapped shapes first. Research their uses from the sources rather than inferring them from appearance.

About the map data

The selected outlines are derived from OpenStreetMap mapping, with editorial names and geometry decisions documented in the dataset. They are approximate mapped extents, not live observations of the water surface. Seasonal changes, source age and mapping gaps can affect what you see.

Islands and separate mapped parts can be part of one water body. A gap between two shapes is not a reason to draw a connecting shoreline. Shape size cannot reliably establish capacity, depth, current storage or flood safety.

Map data © OpenStreetMap contributors, distributed under the Open Database License (ODbL) 1.0. Country outline and reference-layer credits remain available on the map. Source links and review notes appear in the water-body details and the source list below.

Use this playground for learning and comparing mapped locations. For current reservoir conditions, safety decisions or authoritative measurements, consult the relevant operating authority.