Lakes of Obwalden 2026: 12, half larger than 10 ha

Across Switzerland one lake in five tops 10 ha, in Obwalden half. Which ones? ↓

Across Switzerland, only one lake in five is larger than ten hectares. In Obwalden it is 6 of 12, from Lake Sarnen in the valley to the Melchsee at 1893 m.

Number of lakes in Obwalden: 12

12 lakes of half a hectare or more, and yet the national map shows 98 bodies of standing water in Obwalden. The gap is not imprecision; it is a way of counting.

Anyone reading a different figure has almost always drawn a different line: count every water surface and Obwalden has 98; count only lakes over one square kilometre and you get 3. Even a plain name such as "Weiher" counts as official: what decides is the entry in the swissNAMES3D gazetteer. Our count states where the line is, so it can be checked.

Lake Finder: find any lake in Obwalden

Largest lake in Obwalden: Sarnersee

The largest lake touching Obwalden is the Vierwaldstättersee (113.9 km²), but only 2% of its surface lies in the canton. The largest lake belonging entirely to the canton is the Sarnersee: 7.39 km² at 469 m.

Highest lake in Obwalden: Tannensee

The highest lake in Obwalden is the Tannensee in Kerns at 1975 m; the median lake sits at 1755 m.

The canton's lowest-lying lake is the Vierwaldstättersee at 434 m. Elevation is the water level in the landscape model; for reservoirs it varies with how full they are. 3 of the 12 lakes in the canton have a dam or embankment (structures in swissTLM3D): Melchsee, Tannensee and Wichelsee.

Shared lakes: which lakes Obwalden shares

Obwalden shares 1 of its 12 lakes with other cantons, but it makes up only 19% of its lake surface: most of the water in the canton belongs to it alone.

List of lakes in Obwalden

9 of the 12 lakes in Obwalden together cover less area than a single lake, Lungerersee: 1.30 km² against 2.02 km². An official name does not make a lake: 4 of the 16 named bodies of water in Obwalden measure less than half a hectare. The list shows all of them by area, the 12 lakes first, the smaller ones marked.

Lakes by size: 6 larger than 10 ha

6 of the 12 lakes in Obwalden are larger than ten hectares, or 50%. Across Switzerland the share is 20%. By the number of lakes over 10 ha, Obwalden ranks 12 of the 26 cantons.

Measured by area, the small lakes almost vanish: the 4 of the 12 lakes of half a hectare or more that stay under five hectares together cover less than 1% of the lake surface in Obwalden. Sarnersee alone covers 56%.

Lakes by municipality: Kerns has the most

The municipality with the most lakes is not on the canton's largest lake (Sarnersee): Kerns, with 3 lakes, all above 1800 m. Counted are lakes lying entirely within the canton and in no more than two municipalities; a large lake belongs to many. The Lake Finder can search by municipality.

• Kerns3Melchsee · Tannensee · Blausee
• Giswil2Eisee · Arniseeli
• Sarnen2Wichelsee · Sewenseeli
• Alpnach1Wichelsee
• Engelberg1Eugenisee

More lake pages

Written by

Marco Gisler

ConvivaPlus Editor · Data & Switzerland

Writes about Switzerland in figures – official data recalculated, counting method explained.

• Population
• 26 cantons
• Waterways
• Official data

Researched & sourced · for Switzerland

Profile & all articles →·Our editorial teamUpdated 25.10.2026

Source: swisstopo (swissTLM3D, swissNAMES3D, swissBOUNDARIES3D, 2026 edition), analysis by ConvivaPlus. Switzerland as a whole: 891 lakes out of 17'873 water surfaces; parts with the same name no more than 50 m apart count as one lake. Area = water surface at the shoreline of the landscape model; reference works using a different shoreline or water level sometimes give other values.