Name: 20ft Contours (18,056)

Display Field: Contour

Type: Feature Layer

Geometry Type: esriGeometryPolyline

Description: THESE CONTOURS ARE BASED ON PRELIMINARY DATAHouston-Galveston Area Council (H-GAC) provided LiDAR and DEM data for Harris County in December 2024. These contour lines were extrapolated from this preliminary product by Office of the County Engineer (OCE) GIS staff in late 2025 / early 2026 using ArcGIS Pro 3.6.OCE GIS Methodology:H-GAC's provided TIF raster files had a PCS of NAD 1983 2011 UTM Zone 15N (Meters) with a VCS of NAVD_1988 height (Meters). These tiff files were combined into a mosaic dataset with matching a matching spatial reference. From there, the raster was re-projected into NAD 1983 StatePlane Texas S Central DIPS 4204 (US Feet) / NAVD88 height (US Feet). Pixel values were converted from meters to feet using a constant value of 3.2808333 for ftUS. Focal Statistics were run to smooth elevation data and reduce noise using a 3x3 circular neighborhood and median statistics. From there, contours were generated and a Type field was added and field calculated using [MOD(Contour,5)=0] to populate a 5 foot index/intermediate indicator.

Copyright Text: H-GAC, OCE GIS

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 18055.954822

Max Scale: 9029

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: true

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:

XMin: -1.066471761914178E7
YMin: 3501005.7278160173
XMax: -1.0661742846999766E7
YMax: 3503999.323948274
Spatial Reference: 102100  (3857)

Drawing Info:

Renderer:
Simple Renderer:
Symbol:
Style: esriSLSSolid
Color: [255, 139, 43, 255]
Width: 1
Label: N/A
Description: N/A
Transparency: 0
Labeling Info:
Label Placement: esriServerLinePlacementCenterAlong
Label Expression: N/A
Use Coded Values: true
Symbol:
Color: [137, 90, 68, 255]
Background Color: N/A
Outline Color: N/A
Vertical Alignment: bottom
Horizontal Alignment: left
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Font Style: normal
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Max. Scale: 9029.0

Advanced Query Capabilities:

Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false

HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• Id ( type: esriFieldTypeInteger, alias: Id )
• Contour ( type: esriFieldTypeDouble, alias: Contour )
• Type ( type: esriFieldTypeString, alias: Type, length: 35 )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• Shape_Length ( type: esriFieldTypeDouble, alias: Shape.STLength() )

Supported Operations:   Query   Query Attachments   Generate Renderer   Return Updates

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