How real water systems are recreated in the game

Bringing real rivers, lakes, and coastlines into Minecraft relies on public map data, not on making things up. When generating a “real map → world,” TopoBlocks reads the water data publicly mapped in OpenStreetMap — rivers, lakes, reservoirs, coastline outlines — and combines it with open elevation (AWS Terrain) to determine the lay of the land, recreating the land-water boundary in the generated world. The whole pipeline uses the open-source tool Arnis (Apache-2.0).

One thing to be clear about up front: this is an approximate recreation based on public data, not a block-by-block copy. The general course of a river channel and the outlines of lakes and coastlines can be recreated, but it won’t match reality down to every single block, and water depth and riverbed detail are handled approximately.

Fidelity depends on data coverage

How well the water recreates comes down to whether the local OpenStreetMap data is complete:

  • Areas with thorough data — city river channels, well-known lakes, clearly mapped coastlines — usually recreate their shape and position well.
  • Areas with sparse data — remote river segments, unmapped small ponds, or open-sea and deep-water areas — may be missing or look empty.

Precisely because the result depends on the data, TopoBlocks gives a free map quality score before generation. To emphasize: the quality score is an estimate of data coverage, not an accuracy guarantee — it tells you how complete the water, building, and road data is for the area, helping you decide whether it’s worth generating. For how terrain and elevation affect the land-water boundary, see How is terrain and elevation recreated from a real map.

Preview before you pay, confirm before generating

No need to pay blind. Before generation, besides the quality score, there’s also a low-resolution 3D preview, so you can first check whether the position and coverage of rivers, lake shores, and coastlines meet your expectations, and only generate once you’re satisfied.

  • Pay by area in tiers — generation is priced across 6 tiers based on the selected area (roughly 0.2–500 km²), prices are shown in the app, and failed jobs are refunded automatically.
  • Your existing worlds are never overwritten — what’s generated is a brand-new importable .mcworld, a separate new file each time, leaving your original worlds and data intact and traceable.

If what you want to recreate is an island or a whole stretch of coastline, handling the land-water boundary matters even more — see Turning islands/coastlines into a Minecraft world. For the full real-map generation workflow, see the in-depth tutorial Turning a real map into a Minecraft world.