{
  "synthetic": true,
  "description": "Fictional local-grid example. No geometry, population, arrival, capacity or travel-time value describes a real project or place.",
  "coordinate_system": "Local schematic grid in kilometres; not a geographic CRS or GeoJSON",
  "parameters": {
    "background_growth_fraction": 0.06,
    "water_litres_per_person_day": 40,
    "illustrative_clinic_test_minutes": 30,
    "note": "Single-period assumptions chosen to demonstrate arithmetic. Water demand and travel-time values are not technical design standards. Additional residents are net extra residents present in the scenario, not gross cumulative arrivals."
  },
  "nodes": [
    {"id":"gate","name":"Gate","kind":"settlement","x_km":8,"y_km":3,"population_initial":1000,"water_capacity_litres_day":52000,"additional_residents":{"lower":300,"central":600,"higher":900}},
    {"id":"junction","name":"Junction","kind":"settlement","x_km":4,"y_km":3,"population_initial":4000,"water_capacity_litres_day":200000,"additional_residents":{"lower":500,"central":1000,"higher":1500}},
    {"id":"riverside","name":"Riverside","kind":"settlement","x_km":8,"y_km":7,"population_initial":800,"water_capacity_litres_day":32000,"additional_residents":{"lower":120,"central":240,"higher":360}},
    {"id":"hill","name":"Hill","kind":"settlement","x_km":2,"y_km":8,"population_initial":1200,"water_capacity_litres_day":60000,"additional_residents":{"lower":30,"central":60,"higher":90}},
    {"id":"port","name":"Port","kind":"transport","x_km":1,"y_km":1},
    {"id":"clinic","name":"Clinic","kind":"clinic","x_km":4,"y_km":4},
    {"id":"bridge","name":"Bridge","kind":"transport","x_km":8,"y_km":5},
    {"id":"project","name":"Project","kind":"project","x_km":10,"y_km":3}
  ],
  "edges": [
    {"from":"port","to":"junction","dry_minutes":10,"wet_minutes":15},
    {"from":"junction","to":"gate","dry_minutes":12,"wet_minutes":18},
    {"from":"gate","to":"project","dry_minutes":5,"wet_minutes":6},
    {"from":"gate","to":"bridge","dry_minutes":6,"wet_minutes":12},
    {"from":"bridge","to":"riverside","dry_minutes":5,"wet_minutes":20},
    {"from":"junction","to":"hill","dry_minutes":20,"wet_minutes":60},
    {"from":"junction","to":"clinic","dry_minutes":4,"wet_minutes":6}
  ]
}