Spark & Anvil Privacy
Two tween students in rain jackets kneeling on a green hillside after rain, tracing little streams that run downhill into pools and a winding river

💧

RiverForge

Rain doesn’t go wherever it likes. It rolls to the lowest step it can see — again and again — until it pools.

🔮 Open the watershed console →

The whole landscape runs on one rule

Give the land a height at every square, and where the water goes stops being a guess. Water takes the lowest step down, over and over — and that single local rule carves every river, pond, and flood.

  • 💧 Flow & ponds. A drop rolls to its lowest neighbour; a square lower than all four has nowhere to go, so the water pools — a pond.
  • ⛰️ The divide. A ridge splits the rain: one side drains to one pond, the other side to another. The line between is the watershed divide.
  • 🌊 Floods are paths joining. Many squares’ paths merge onto the low ones, so those carry the most water and flood first — not more rain, just more paths meeting.
  • 🧱 Levees move water. Wall off one low spot and the water reroutes to the next — protecting one place can flood another.

Everything runs on your device — no internet, no accounts.

Meet the crew — the shape of a watershed

  • Divide is the ridge along the top — the line that sends rain on one side to one river and rain on the other to a different one.
  • Slope is the rule every drop obeys: always take the lowest step down, never uphill.
  • Channel is where many paths merge into one — the square that carries the most water, and floods first.
  • Basin is the low pond at the end of the journey, where all the water finally pools.
  • Delta (mentor) is the wise river-mouth who’s seen where all water ends up, and reminds the crew that a levee doesn’t remove water — it just moves where it collects.

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