Jefferson County Benchmark Network Information
Flood Zone A - Areas within the 100 year floodplain
Flood Zone B - Areas within the 500 year floodplain
Flood Zone C - Areas of minimal flooding
The information related to benchmarks displayed on this web site was provided by the Jefferson County Engineer's Office as a service to the community. The Jefferson County Engineer and all other Jefferson County Agencies provide no warrantees or claims to the accuracy of the information contained within this website related to flood zones, frequency and or locations of flooding and the accuracy of GPS benchmark data.
Vertical and Horizontal Data Source:
The vertical data provided for benchmarks are provided in feet mean sea level. The elevations were derived from the NGS monument G1018 also known as JCAD 59 located on HWY 124 using high precision GPS surveying techniques. After finalizing the control network and primary benchmark survey the network elevations were compared to the NGS monument F1017 located at the Jefferson County Airport. F1017's elevation was published to be 16.47 ft by NGS the control network returned an elevation of 16.45 ft. The Horizontal information was acquired using the WGS1984 horizontal geodetic datumn.
GPS processing was performed using SKI 2.3 software in conjunction with Geoid96 and Geoid99 provided by the NGS. The GPS Surveying the GPS Processing was completed by Carroll & Blackman, Inc., 1360 7th Street, Beaumont Texas 77702. For questions about the survey related information contained in this web site please contact Rick Masters.
Please contact Ronald Westphal with any comments or suggestions related to this website. Your interest in this web site and any ideas for improvements will be appreciated.