Records in the live release
227
Release 2026-11-11, 13 November 2026. Its fingerprint: e1f4082650774dcb6fdc96f0c22035ab323a862213c6351444faa09463b98c08 (what that is).
Datasets·UM-318·Water·Early access
Dams from space
How much of each dam's full outline is under water, seen from space every month since 2017 and in clear satellite pictures since 1984, beside the department's own level. Measured from space, not the department's reading.
01
What it holds
In more detail
The water surface of each DWS dam measured from space: every month since 2017 from Sentinel-2 and in every clear Landsat look since 1984 through Digital Earth Africa (Waterbodies' method), with a picture a year and the comparison with DWS's level. Measured from space, not a DWS reading.
How far it reaches
189 of DWS's 227 dam stations (those with a full-supply outline from OpenStreetMap): the water surface each month from Sentinel-2 since January 2017, the year's average water surface from Landsat (Digital Earth Africa) since 1984, true-colour pictures a season since 2017 and a year 1984 to 2016, and a comparison with DWS's weekly level; since 12 Nov 2026 each dam's footprint from Digital Earth Africa's all-time water, Sentinel-1 radar for cloudy weeks, and an estimated % full from space with a band for 97 dams calibrated on DWS. 38 stations have no clean outline yet.
How often it changes
Monthly
Monthly from the Mac, after the month's Sentinel-2 scenes are in (RUNBOOK, dam-surface-from-space).
Where the figures come from
European Space Agency (Copernicus Sentinel-2); Digital Earth Africa (from USGS Landsat); OpenStreetMap contributors. Contains modified Copernicus Sentinel data and Digital Earth Africa products (free and open); dam outlines from OpenStreetMap (ODbL 1.0, offered at https://unmapped.co.za/open#dam-outlines).
02
Measured accuracy
Not checked against a source page: its figures are measured from satellite pictures, not printed on a page. 50 records sampled on 12 November 2026. The sample and any failures.
03
Get it
On this site
See the dams from space, free, no account.
Through the API
/v1/datasets/dam-surface-from-space/records, as JSON, CSV or Excel, with filters and any past date. Fields and filters. It takes a key.
All of it at once (Parquet)
The full history, built with release 2026-11-10.3. A download takes a key; the fingerprints are public. How to download a snapshot.
dam-surface-from-space-2026-11-10.3-records.parquet: 536 record rows (every release), 1.0 MB. sha2564acd12d313b56ea3…dam-surface-from-space-2026-11-10.3-facts.parquet: 52,353 facts with their pages, 1.7 MB. sha256d28d85bf808198a3…
For data portals
Described in DCAT in /catalog.json and on this page.
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