Floodline is a flood-defense simulation built by a licensed water-resources engineer. You place levees, channels, pumps, and sandbags to keep town damage below a scenario threshold while storms raise river stages and saturate soils. The browser demo includes a training sandbox and Cedar Rapids 2008; the full release on itch.io adds the complete historical campaign described below.
Why scenarios matter
Each scenario ships with a storm hydrograph, terrain derived from real valley geometry, budget constraints, and win conditions tied to damage percentage. Parameters are simplified for play but grounded in post-event reports from agencies such as California DWR, USACE, and USGS multi-hazard studies.
| Scenario | Event basis | What you manage |
|---|---|---|
| Training Ground | Synthetic tutorial basin | Learn levee stress, pumps, and channel routing without time pressure. |
| 1986 Yuba | Yuba County levee failures | Fast-rising Sacramento Valley flows; sandbag windows are short. |
| 1997 New Year's | California statewide flood | Multi-day rain on saturated soils; duration stress on levees. |
| 2006 Sacramento | Sacramento River high flows | Urban ring levees and pump capacity under prolonged stage. |
| 2017 Oroville | Oroville Dam spillway crisis | Spillway erosion, auxiliary spillway risk, evacuation timing — widely considered the hardest scenario. |
| ARkStorm West / East | USGS synthetic atmospheric river | Hypothetical megastorm footprints used in California resilience planning. |
| Cedar Rapids 2008 | Midwest slow crest | Gradual rise over days — a endurance scenario for pumps and pre-positioning. |
Core mechanics across all scenarios
- Levee stress accumulates when water sits high against a segment; breached levees redirect flow unpredictably.
- Pumps buy time but cannot defeat physics if inflow exceeds system capacity.
- Wallet money carries between scenarios in campaign mode — spend on upgrades or save for harder storms.
- Evacuation tools appear in urban scenarios where population risk is part of the score.
Is it an engineering tool?
No. Floodline uses first-order hydrology appropriate for gameplay: routing, storage, and simplified gate curves. It is faithful in shape to real events, not a replacement for HEC-RAS or dam safety modeling. Treat it as an interactive way to understand why flood managers obsess over freeboard, spillway capacity, and forecast lead time.