generated: '2026-07-27'
method: derived
source:
- openapi/atco-electric-hosting-capacity-layer-0.esri.json
- openapi/atco-electric-hosting-capacity-openapi.yml
- live anonymous queries against the running service, 2026-07-27
docs: null
docs_note: >-
  ATCO publishes no object reference or data dictionary. Field names, types, aliases and lengths
  below come verbatim from the layer descriptor; cardinalities and value samples come from live
  anonymous queries. Where a field's intent is undocumented, that is stated rather than guessed.
summary:
  entities: 1
  relationships: 0
  relationships_note: >-
    The layer declares `relationships: []` — there are no related tables and no joins. The model
    is a single flat feature class. The substation and feeder hierarchy below is implicit in
    attribute values, not modelled as entities.
  feature_count: 880623
  feature_count_verified: '2026-07-27'
entities:
- name: HostingCapacitySegment
  layer: 0
  layer_name: Hosting Capacity (KW)
  type: Feature Layer
  geometry_type: esriGeometryPolyline
  primary_key: OBJECTID
  display_field: SUB_NAME
  spatial_reference:
    wkid: 102185
    latest_wkid: 3401
    name: NAD83 / Alberta 3TM ref merid 115 W
    units: esriMeters
  extent:
    xmin: -320923.26889999956
    ymin: 5629354.7049
    xmax: 351844.33800000045
    ymax: 6582097.7320000008
  description: >-
    One feeder segment of ATCO Electric's Alberta distribution system, carrying the distributed
    energy resource hosting capacity in kilowatts that the segment can accept. Sourced from a
    CYME hosting capacity study ("CYME Hosting Capacity Map" is the service description).
  count: 880623
  fields:
  - name: OBJECTID
    type: esriFieldTypeOID
    role: primary_key
    nullable: false
    editable: false
  - name: FEEDER
    alias: CIRCUIT
    type: esriFieldTypeString
    length: 200
    role: grouping_key
    description: Feeder / circuit identifier. Groups segments into a distribution circuit.
    sample: 700-508
  - name: PHASE
    type: esriFieldTypeString
    length: 200
    role: attribute
    description: Phase designation of the segment.
    samples: [B, AB]
  - name: SUB_NAME
    type: esriFieldTypeString
    length: 200
    role: grouping_key
    description: Substation name. The layer's displayField and the natural top-level grouping.
    distinct_values: 135
    distinct_verified: '2026-07-27 via returnDistinctValues=true'
    sample: BONNYVILLE
  - name: SUB_NUM
    type: esriFieldTypeString
    length: 200
    role: grouping_key
    description: Substation number. Pairs with SUB_NAME.
    sample: 700S
  - name: DATELOADED
    type: esriFieldTypeString
    length: 200
    role: provenance
    description: >-
      CYME study load date as an unpadded YYYYMMDD string. Stored as a string, not a date field,
      so it cannot be filtered with date semantics.
    sample: '20251031'
  - name: DER_CAP_KW
    type: esriFieldTypeDouble
    role: measure
    unit: kW
    description: DER hosting capacity for the segment. The field the map's class-breaks renderer symbolizes.
    sample: 62.9
    renderer_class_breaks: ['<1000', '1000-4999', '5000-9999', '10000-14999', '>=15000']
  - name: DER_CAP_KW1
    type: esriFieldTypeDouble
    alias: DER_CAP_KW
    role: measure
    unit: kW
    description: >-
      Second capacity field carrying the same alias as DER_CAP_KW. Observed equal to DER_CAP_KW
      in every sampled feature. ATCO publishes no field definitions, so the intended distinction
      (e.g. a second study scenario) is undocumented and is not guessed here.
    sample: 62.9
  - name: PROJECT_AREA
    alias: PROJ_AREA
    type: esriFieldTypeString
    length: 50
    role: attribute
    description: Project area. Null in sampled features.
  - name: SE_ANNO_CAD_DATA
    type: esriFieldTypeBlob
    role: internal
    description: ArcSDE annotation CAD blob carried over from the source geodatabase. Empty in sampled features; not useful to consumers.
  - name: Shape__Length
    type: esriFieldTypeDouble
    role: derived_geometry
    unit: metres
    editable: false
    description: Segment length, maintained by the geometry engine.
    sample: 678.11243656856732
  indexes:
  - fields: OBJECTID
    unique: true
    type: Attribute
  - fields: SHAPE
    unique: false
    type: Spatial
  - fields: Shape__Length
    unique: false
    type: Attribute
relationships: []
implicit_hierarchy:
  note: >-
    Not modelled as entities by the service, but present in the attribute values and usable as a
    grouping hierarchy in queries via groupByFieldsForStatistics or /0/queryTopFeatures.
  levels:
  - level: substation
    fields: [SUB_NAME, SUB_NUM]
    cardinality: 135 distinct SUB_NAME values
  - level: feeder
    fields: [FEEDER]
    parent: substation
  - level: segment
    fields: [OBJECTID]
    parent: feeder
    cardinality: 880623
  example_verified: >-
    where=SUB_NAME='BONNYVILLE' returned 34,009 segments (2026-07-27).
id_prefixes: []
id_prefixes_note: There are no typed/prefixed identifiers. OBJECTID is a plain integer.
render: null
render_note: No subway/ or ERD visual exists for this repo; a single-entity flat model does not warrant one.