Data Formatting Guide:
Rhino & ArcGIS Pro

01Overview

This guide is for designers and GIS analysts who create flood protection geometry in Rhino or ArcGIS Pro and need to format that work for the BCA flood analysis pipeline. It covers the exact geometry types, attribute fields, naming conventions, and coordinate system requirements the pipeline expects.

For the mechanics of actually loading formatted data into the pipeline, see the companion Data Loading Guide.

02Quick Reference: What to Produce

Every feature you create falls into one of three categories. Each has a required geometry type and a small set of required attributes. Both measure_type and measure_name are automatically determined — measure_type from the Rhino layer name, and measure_name as a sequential label (e.g., levee_1, levee_2) if not set via SetUserText or Rhino object name. The table below shows the attributes you should provide, along with default values that apply if you don't override them.

03Rhino Workflow

Layer Setup

Organize your Rhino model using the layer names below. The ingestion script maps each layer to a pipeline target directory. Layer names are case-insensitive and spaces are treated as underscores. Any layer not in this list is skipped with a warning.

Each layer automatically sets measure_type and default attribute values. You only need to use SetUserText on an object if it differs from the layer default. See the Quick Reference table for the full list of defaults per measure type.

Geometry Rules

The ingestion script converts Rhino geometry to 2D GeoJSON. Follow these rules to ensure clean conversion:

Curve Simplification

NURBS curves, arcs, and splines are sampled at 0.5m intervals (max 500 vertices). If your barrier alignment has complex curvature, the sampled output will still be accurate to sub-metre precision. For simple straight-line barriers, use a basic polyline to keep vertex counts low.

User Text Attributes

Select an object in Rhino and use the SetUserText command to attach key-value pairs. These override the layer defaults for that specific object.

// Barrier with specific crest elevation
SetUserText crest_elevation_m 5.33
SetUserText width_m 2.5
SetUserText measure_name "East Harlem Seawall Section A"

// Pump station with custom capacity
SetUserText capacity_cms 12.5
SetUserText measure_name "West 225th St Pump"

// Building with usage data
SetUserText use_category multi_family
SetUserText replacement_value_usd 1200000
SetUserText first_floor_height_m 0.46

Coordinate System

The ingestion script assumes your Rhino model is in UTM Zone 18N (EPSG:32618) by default, which means your model units should be metres and your coordinates should be in UTM easting/northing.

If your model uses a different CRS, specify it at ingest time:

# NY State Plane Long Island (US survey feet)
python scripts/ingest_cad.py my_design.3dm --source-crs EPSG:2263

# NY State Plane Long Island (metres, NAD83 2011)
python scripts/ingest_cad.py my_design.3dm --source-crs EPSG:6539

Rhino Export Checklist

Before saving your .3dm file for ingestion:

• All barrier alignments are open polylines (not closed)
• All area features (basins, green infra, buildings) are closed curves
• Pump stations are Point objects, not short lines or circles
• Culverts are open polylines drawn from inlet to outlet
• Every object is on a recognized layer (barriers, levee, seawall, gate, platform, pump, culvert, retention, green_infra, buildings)
• crest_elevation_m is set on all barrier objects (via SetUserText or layer default)
• use_category is set on all building footprints
• All elevation values are in metres NAVD88, not feet
• No stray geometry on unmapped layers (or you're okay with it being skipped)
• Model units match the CRS you'll declare at ingest time

04ArcGIS Pro Workflow

Feature Class Setup

In ArcGIS Pro, organize your data into separate feature classes (or layers in a geodatabase) by measure category. Each feature class should contain a single geometry type.

Geometry Rules

Attribute Table Schema

Add these fields to your feature class attribute tables. The pipeline reads property names from the GeoJSON properties object, which mirrors your attribute table column names. Field names are case-sensitive and must use snake_case.

Barriers (Polyline Feature Class)

Stormwater — Pump Stations (Point Feature Class)

Stormwater — Culverts (Polyline Feature Class)

Stormwater — Areas (Polygon Feature Class)

Custom Buildings (Polygon Feature Class)

Coordinate System

GeoJSON files must be in WGS 84 (EPSG:4326) with coordinates as [longitude, latitude] in decimal degrees. If your ArcGIS Pro project uses a projected CRS (State Plane, UTM, etc.), the export tool will reproject automatically — but you should verify the output CRS after export.

Export to GeoJSON

Use the Features to JSON geoprocessing tool in ArcGIS Pro. After export, you need to add the collection-level metadata fields that the pipeline expects.

{
  "type": "FeatureCollection",
  "name": "my_barriers",            // machine ID (snake_case, no spaces)
  "label": "My Custom Barriers",    // display name
  "description": "Barrier set for...", // optional
  "category": "barriers",            // "barriers" | "stormwater" | "building"
  "features": [ ... ]
}

import arcpy, json

fc = "my_barriers"                   # feature class name
out = "protection_measures/barriers/my_barriers.geojson"

# Export to temp GeoJSON
arcpy.conversion.FeaturesToJSON(
    fc, out.replace(".geojson", "_tmp.geojson"),
    geoJSON="GEOJSON",
    outputToWGS84="WGS84"
)

# Add collection-level metadata
with open(out.replace(".geojson", "_tmp.geojson")) as f:
    data = json.load(f)

data["name"] = "my_barriers"
data["label"] = "My Custom Barriers"
data["category"] = "barriers"

with open(out, "w") as f:
    json.dump(data, f, indent=2)

print(f"Exported {len(data['features'])} features to {out}")

05Barriers: Detailed Formatting

Barriers are the most critical feature type. They modify the SFINCS hydrodynamic model terrain by rasterizing the crest elevation along the alignment onto the DEM grid. Incorrect formatting here will cause modeling errors.

Geometry

• Type: LineString (open polyline / polyline feature). Do not close barrier alignments into rings.
• Vertex density: Include enough vertices to capture the alignment faithfully. The model rasterizes at 1m DEM resolution, so vertices every 2–5m along curves are sufficient.
• Direction: Vertex order does not matter for modeling, but consistent direction (e.g., south-to-north along a river) improves readability.
• Segmentation: Split a long barrier into multiple features only if segments have different crest elevations or types. Otherwise, keep it as one continuous LineString.

Required Attributes

Optional Attributes

Example: Complete Barrier Feature

{
  "type": "Feature",
  "geometry": {
    "type": "LineString",
    "coordinates": [
      [-73.9348, 40.8353],
      [-73.9341, 40.8339],
      [-73.9335, 40.8322],
      [-73.9348, 40.8299]
    ]
  },
  "properties": {
    "measure_type": "levee",
    "measure_name": "East Harlem — Seawall",
    "crest_elevation_m": 5.33,
    "width_m": 2.5,
    "scenario": "harlem_river_frontline",
    "scenario_label": "Harlem River Frontline Seawall"
  }
}

06Stormwater: Detailed Formatting

Pump Stations

Pump stations are Point features located where the pump removes water from the model. They are the simplest feature to format.

Culverts

Culverts are LineString features drawn from inlet to outlet. The line direction defines the flow path. In SFINCS, culverts are modeled as passive drainage structures that convey water along the alignment at the specified capacity.

Retention Basins

Retention basins are Polygon features representing the storage footprint. Draw the polygon to match the basin's plan-view footprint.

Green Infrastructure

Green infrastructure is a Polygon representing the coverage area of a distributed network (bioswales, rain gardens, permeable pavement, etc.). It need not represent individual installations; draw it as the overall service area.

07Custom Buildings: Detailed Formatting

Custom buildings represent proposed developments, hypothetical structures, or corrections to the NYC building database. They must be Polygon features representing the building footprint.

use_category Values

This is the only required attribute. It determines which HAZUS depth-damage curve is applied and what default first-floor height is assumed.

Optional Attributes

08Units & Vertical Datums

All Values Are Metric

The pipeline uses metres for all dimensions and elevations. If your source data is in feet, convert before setting attributes. Common conversions:

Vertical Datum: NAVD88

All elevation attributes (crest_elevation_m, ground_elevation_m, etc.) must reference NAVD88. The pipeline defines these offsets for other tidal datums at the study area:

Horizontal CRS

09Naming Conventions

File Names

• Use snake_case: harlem_river_seawall.geojson, not Harlem River Seawall.geojson
• Use .geojson extension (not .json)
• Name should be descriptive of the contents: frontline_barriers.geojson, west_225th_pump.geojson

measure_type Values

These are the exact, case-sensitive strings the pipeline recognizes:

scenario Identifiers

• All lowercase, underscores for spaces: harlem_river_frontline
• Keep them short but descriptive
• Pair with a scenario_label for the human-readable version: "Harlem River Frontline Seawall"
• Features with the same scenario value are grouped together for modeling

GeoJSON Collection Metadata

Every .geojson file needs these top-level fields in the FeatureCollection:

10Common Pitfalls

11Pre-Flight Checklist

Run through this checklist before handing off your data. Items marked with Rhino or ArcGIS apply to that tool only; unmarked items apply to both.

Geometry

• Barriers are open polylines / LineStrings (not closed)
• Area features (basins, green infra, buildings) are closed curves / Polygons
• Pump stations are Points (not buffered polygons or short lines)
• No self-intersecting geometry
• Barrier segment endpoints are snapped where they should connect
• Multi-part features are exploded into single-part features
• Rhino No stray geometry on unmapped layers
• ArcGIS Multipatch features are flattened to 2D

Attributes

• measure_type is set on every protection measure feature (exact lowercase string)
• measure_name is set on every protection measure feature (or auto-generated as {type}_1, {type}_2, …)
• crest_elevation_m is set on all barrier features
• use_category is set on all custom building features
• All elevation values are in metres NAVD88 (not feet, not MHHW)
• retention_pct is a fraction (0–1), not a percentage
• capacity_cms is in m³/s (not GPM or L/s)
• Rhino Attributes set via SetUserText (not Z coordinates)
• ArcGIS Field names are snake_case and match this guide exactly

Coordinate System & Export

• ArcGIS GeoJSON export is in WGS 84 (EPSG:4326)
• ArcGIS Coordinates look like [-73.9, 40.8] (not [583000, 4515000])
• ArcGIS Collection-level metadata (name, label, category) is present
• Rhino Model units match the CRS you'll declare at ingest time
• Rhino If not UTM 18N, you know the --source-crs EPSG code
• File extension is .geojson
• Filename uses snake_case (no spaces)