Lakes and their surface elevation

On a lake, the elevation model returns the water surface, not the bottom. With out center; and elevation=1, every lake gets its surface elevation.

This query lists the named lakes of Switzerland, from the highest mountain lakes down to the lakes of Ticino.

The query

[out:json][timeout:90];
area["ISO3166-1"="CH"][admin_level=2]->.ch;
nwr["natural"="water"]["water"="lake"]["name"](area.ch);
out center;

Run it

Live result from overpass.ch, cached for up to 12 hours. Map data © OpenStreetMap contributors (ODbL). Heights produced using Copernicus WorldDEM™-90 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved. Sea depths: GEBCO Compilation Group (2026) GEBCO 2026 Grid.

How it works

1. ["natural"="water"]["water"="lake"]["name"] finds named lakes. Big lakes are multipolygon relations.
2. out center; gives the centre of the bounding box around each lake, and elevation=1 the height there.
3. For the lakes with an ele tag, the median difference is below 1 m.
4. The centre of a long, curved lake can fall on the shore: for Lago Maggiore it reads 256 m instead of 193 m. For those, look up a point you know is on the water.

Variations

• Reservoirs: ["water"="reservoir"]; their dams are way["waterway"="dam"].
• The outlines: out geom;, as in named lakes of a country. With elevation=1 every outline point then gets a height, which uses many more lookups.

Run it from your code

The query is unchanged; elevation=1 in the URL adds the heights. Each height uses one lookup from your elevation allowance.

curl 'https://api.overpass.ch/v1/YOUR_API_KEY/interpreter?elevation=1' \
  --data-urlencode 'data@query.overpassql'

import requests

query = open("query.overpassql").read()
r = requests.post("https://api.overpass.ch/v1/YOUR_API_KEY/interpreter",
                  params={"elevation": 1}, data={"data": query}, timeout=120)
r.raise_for_status()
for el in r.json()["elements"]:
    height = el.get("elevation") or el.get("center", {}).get("elevation")
    print(el.get("tags", {}).get("name"), height)

const res = await fetch("https://api.overpass.ch/v1/YOUR_API_KEY/interpreter?elevation=1", {
  method: "POST",
  body: new URLSearchParams({ data: query }),
});
if (!res.ok) throw new Error(await res.text());
const { elements } = await res.json();
for (const el of elements) console.log(el.tags?.name, el.elevation ?? el.center?.elevation);

Save the query as query.overpassql. It works the same in Overpass Turbo, QGIS and JOSM.