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snippet: Preliminary Harris County 2025 1ft-interval contours derived from a H-GAC DEM.
summary: Preliminary Harris County 2025 1ft-interval contours derived from a H-GAC DEM.
accessInformation: H-GAC, OCE GIS
thumbnail:
maxScale: 5000
typeKeywords: []
description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN STYLE="font-weight:bold;">THESE CONTOURS ARE BASED ON PRELIMINARY DATA</SPAN></P><P><SPAN>Houston-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.</SPAN></P><P><SPAN>OCE GIS Methodology:</SPAN><SPAN>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.</SPAN></P></DIV></DIV></DIV>
licenseInfo: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN STYLE="font-weight:bold;font-size:12pt">This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey and represents only the approximate relative location of property boundaries and other geographic features. All data, specifically including the geographic data herein are provided “as is” without warranty of any kind, either expressed or implied. Use of the information is the sole responsibility of the user.</SPAN></P></DIV></DIV></DIV>
catalogPath:
title: Contours_4KM_Test
type:
url:
tags: ["Contours","Elevation","Topography","Isolines","DEM","Terrain","Interval","1ft","H-GAC","Harris County","LIDAR","2025","Preliminary","Draft"]
culture: en-US
name:
guid:
minScale: 500000
spatialReference: