OPR-K371-TJ-18Approaches to HoustonBetween Galveston Bay Entrance and Sabine Bank Channels, Texas and LouisianaNOAA Ship THOMAS JEFFERSONH130483NoneBetween Galveston Bay Entrance and Sabine Bank ChannelTexasUnited States400002018Christiaan van Westendorp, CAPT/NOAANavigable Area2018-03-082018-06-092018-08-07Multibeam Echo SounderSide Scan Sonar & Multibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNoneNoneNOAASurvey H13048 extended from 49 NM to 77 NM southeast of the entrance to Galveston Bay, TX between the traffic safety fairways that lead into Galveston Bay, TX and Sabine Pass, LA (Table 1 and Figure 1).28.97103893.88574928.7863493.407275Overview of area surveyedfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/a1_survey_area_limits.pngSheet limits for H13048 were extended north-east of original sheet limits (Figure 2).Overview of extended survey areafile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/a1_survey_limits_extension.pngThe purpose of survey project OPR-K371-TJ-18 is to provide contemporary surveys to update National Ocean Service nautical charts and products in an area critical to the nation's economy. In 2015, the Port of Houston supported $137 Billion in trade, ranked first in the nation for foreign tonnage. was the nation's largest importer/exporter of petroleum products and supported 509,000 jobs directly or indirectly.* This survey project covers approximately 1100 square nautical miles between the Galveston Bay and Sabine Bank Channels in an area which has not been surveyed since 1963. The current chart coverage shows numerous reported wrecks and obstructions with their positions reported to be approximate; these pose a risk to surface navigation. This survey will identify changes to the bathymetry and resolve position uncertainty in known hazards.The entire survey is adequate to supersede previous data.All waters in survey areaComplete Coverage (refer to HSSD Section 5.2.2.3)Survey coverage was in accordance with the requirements listed above and in the HSSD.Survey coverage within project limits for project OPR-K371-TJ-18file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/a4_survey_coverage_01.pngSurvey coverage for H13048file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/a4_survey_coverage_02.pngS222044900023770113004490002377011304.011000148.32018-06-092018-06-102018-06-112018-06-122018-06-132018-06-142018-06-152018-06-162018-06-172018-06-282018-06-292018-06-302018-07-032018-07-042018-07-062018-07-102018-07-232018-08-022018-08-032018-08-042018-08-052018-08-062018-08-07Refer to the Data Acquisition and Processing Report (DAPR) for a complete description of data acquisition and processing systems, survey vessels, quality control procedures and data processing methods. S22220815Refer to DAPR for OPR-K371-TJ-18 for a complete description of equipment used.Kongsberg MaritimeEM 2040MBESKongsberg MaritimeEM 710MBESKlein Marine SystemsSystem 5500 V2SSSApplanixPOS MV 320 v5Navigation and Attitude SystemAML OceanographicMVP100Sound Speed Profiling SystemAML OceanographicMicro-CTDConductivity, Temperature, and Depth SensorAML OceanographicMVP-X CTDConductivity, Temperature, and Depth SensorSea-Bird ScientificSBE 19plusConductivity, Temperature, and Depth SensorValeportThru-Hull SVSSound Speed SystemVessel configurations, equipment operations, and data acquisition and processing were consistent with specifications described in the DAPR.MBES crossline mileage equaled 4% of MBES mainscheme mileage. The mean difference of values of overlapping data from H13048 mainscheme MBES data and H13048 crossline MBES data was 0.0 m with a standard deviation of 0.1 m (Figure 5). H13048 MBES crossline comparison statisticsfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b21_xline_comp.png0.080.13ERS via VDATUMS2224.02.00.2Statistical analysis of the uncertainty layer for the MBES CUBE surface shows that specifications related to MBES uncertainty were met (Figure 6).H13048 MBES surface uncertainty statisticsfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b21_uncertainty.pngH13048 junctioned with three surveys from project OPR-K371-TJ-18 (Figure 7). H13048 survey junctionsfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b23_junctions.pngH13044400002018NOAA Ship THOMAS JEFFERSONNWThe mean difference of values of overlapping data from sheets H13048 and H13044 was 0.0 m with a standard deviation of 0.1 m (Figure 8). H13044 Junctions Analysisfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b23_junctions_h13044.pngH13045400002018NOAA Ship THOMAS JEFFERSONNThe mean difference of values of overlapping data from sheets H13048 and H13045 was 0.0 m with a standard deviation of 0.1 m (Figure 9). H13045 Junctions Analysisfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b23_junctions_h13045.pngH13047400002018NOAA Ship THOMAS JEFFERSONWThe mean difference of values of overlapping data from sheets H13048 and H13047 was 0.0 m with a standard deviation of 0.1 m (Figure 10). H13047 Junctions Analysisfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b23_junctions_h13047.pngSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Data artifact sometimes present in MBES data:MBES data on S222 can sometimes exhibit an artifact under certain environmental conditions. A discussion of the probably causes and impact of the data artifact on overall data quality is outlined in the DAPR. MBES data quality is monitored in real-time and in post processing. All MBES data collected on H13048 was deemed to be acceptable to meet survey specifications. Refraction induced data artifacts sometimes present in SSS imageryData artifacts sometimes present in SSS imagery indicated the presence of a significant and/or variable sound speed gradient in the water column during certain periods of survey. Additional SSS 'split lines' were acquired over all areas where sound speed refraction artifacts significantly degraded image quality (Figures 11 and 12 below). SSS 'split lines'file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b26_sss_splits.pngSSS imagery data artifact examplefile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b26_sss_refraction.pngCTD/MVP casts were taken in accordance with the procedures outlined in the DAPR. MVP cast frequency was frequently reduced due to the risk of entangling the MVP gear with the towed SSS gear during periods of significant cross currents; cast distribution is somewhat uneven and several casts were conducted outside of MBES coverage as a result; however, cast frequency and distribution complied with HSSD requirements. Environmental conditions for casts taken outside of the prescribed survey limits represented the environmental conditions present within the survey area in all cases (Figure 13). Geographic distribution of sound speed castsfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b24_sound_speed_geographic_distribution.pngConcurrent MBES bathymetric and 100% SSS sonar coverage was used to obtain Complete Coverage (Option B. as described in section 5.2.2 of HSSD 2018) for the majority of the survey. 100% bathymetric bottom coverage using MBES (Option A. as described in section 5.2.2 of HSSD 2018) was used to obtain Complete Coverage during the final days of operations on the project. Three holidays in 100% SSS coverage exist within the extents of the main SSS mosaic; however, all instances of holidays in SSS coverage were addressed via 100% complete coverage MBES coverage. No holidays exists within the the survey limits in combined complete coverage MBES and SSS coverage. Data Density AnalysisAn analysis of data density for the MBES surface shows that the final MBES surface meets HSSD specifications (Figure 14). H13048 MBES density statistics file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b21_density.pngAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR (Figure 15). Composite backscatter mosaic for H13048file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/b4_backscatter_mosaic.pngNOAA Profile V_5_8NOAA extended attribute files and profiles settings were used as described in the DAPR. H13048_MB_1m_MLLW_final.csarCARIS Raster Surface (CUBE)114.630.7NOAA_1mComplete MBESH13048_MB_1m_MLLW.csarCARIS Raster Surface (CUBE)114.630.7NOAA_1mComplete MBESH13048_SSSAB_1m_455kHz_1of1.tiffSSS Mosaic114.630.7N/A100% SSSH13048_MBAB_1m_S222_300kHz_1of2.tifMB Backscatter Mosaic114.630.7N/AMBES BackscatterH13048_MBAB_1m_S222_70kHz_2of2.tifMB Backscatter Mosaic114.630.7N/AMBES BackscatterComplete coverage requirements were met by either 100% SSS and concurrent MBES or complete coverage MBES per Section 5.2.2.3 of the HSSD 2018. Density requirements were met for H13048 and all MBES data was gridded at a 1m resolution; see Project Correspondence for single grid resolution waiver. SSS data was mosaiced at a 1m resolution.No Horizontal Vertical Control Report (HVCR) accompanies this survey.Mean Lower Low WaterERS via VDATUMOPR-K371-TJ-17_WGS84-MLLW_Geoid12B.csarAll soundings were reduced to MLLW using VDATUM techniques as outlined in the DAPR.World Geodetic System (WGS) 1984Projected UTM 15NThe Fugro Marinestar commercial real-time satellite based corrector service was used to meet ERS specifications for GNSS positioning. Chart comparisons for all ENCs listed below were conducted as described in the DAPR. US3GC02M250000332018-07-112018-10-03falseUS3GC02M is the largest scale chart covering the H13048 survey area. Two significant discrepancies between charted sounding values and observed depths were observed: (1) an obstruction in the north-eastern portion of the sheet charted at 14.6 m with an observed least depth of 15.1 m (Figure 16); and (2) a charted 17.6 m sounding in an area characterized by an observed least depth of 19.9 m. All other soundings generally agreed with observed data (Figure 17). The least depth of a charted 14.6 m obstruction was observed to be 15.1m; the obstruction was mischarted by 208m. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_chart_comparison_01.pngA charted 17.6 m shoal sounding was unobserved in the data. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_chart_comparison_02.pngNo Maritime Boundary Points were assigned for this survey.21 features were assigned for investigation within the original survey limits for H13048; an additional 16 features were assigned for investigation within the extended area of H13048. All assigned features were addressed. Two assigned wrecks were designated as Position Approximate (PA)features; both of the PA wrecks were located (Figures 16 above and 18 below). An obstruction with an unknown depth was disproved in accordance with HSSD and assigned search radius criteria (Figure 19). Numerous wellhead obstructions were assigned and addressed in accordance with HSSD and assigned search radius criteria. Reference the Final Feature File for further information.A Position Approximate obstruction was mischarted by 406m. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_charted_features_01.pngAn obstruction with an unknown depth was disproved.file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_charted_features_02.png Three uncharted features were found within the survey area. One of the uncharted features was assigned for investigation as a wellhead obstruction (Figures 20, 21, and 22 below). Reference the Final Feature File for further information. An uncharted obstruction with a height of approximately 1.3 m; least depth of 22.6 m; close to a charted 22.2 m sounding. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_uncharted_features_01.pngAn uncharted obstruction with a height of approximately 2 m; least depth of 21.1 m; depth of surrounding waters approx. 23 m. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_uncharted_features_02.pngAn uncharted obstruction with a height of approximately 1.4 m; least depth of 22.6 m; depth of surrounding waters approx. 23.9 m; wellhead obstruction assigned for investigation. file:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d11_uncharted_features_03.pngOne PA wreck and one uncharted pipelines were submitted as DTONs. Reference the H13048 Danger to Navigation Reports (included with this report as Supplemental Survey Records and Coorespondence) and the Final Feature File for further information. No channels exist for this survey. There are no designated anchorages, precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits.The number and distribution of bottom samples were adjusted from the original sample plan provided after an analysis of the SSS and MBES backscatter mosaics. Eleven bottom samples were collected by S-222 to cover the distinct bottom types within the survey sheet limits (Figure 23). Reference the Final Feature File for further information.Bottom sample site distributionfile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d17_bottom_samples.pngShoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.No prior survey comparisons exist for this survey.One charted buoy was unobserved and one uncharted buoy was observed. Reference the Final Feature File for further information. No overhead features exist for this survey.Numerous submarine pipelines exist within the survey area. One exposed pipeline was observed and reported to the Bureau of Safety and Environmental Enforcement (BSEE) in accordance with HSSD requirements (Figure 24). One uncharted pipeline was observed and submitted as a DTON; see (Figure 25). Reference the Final Feature File and Project Correspondence for further information. Exposed pipelinefile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d25_pipeline_01.pngUncharted pipelinefile:///I:/Surveys_Archive/OPR-K371-TJ-18/H13048/Processed/Reports/Survey/Descriptive_Report/Report/SupportFiles/d25_pipeline_02.pngA number of charted platforms and assigned wellheads were assigned and investigated. No platforms were observed within the survey limits and one of the assigned wellhead obstructions was observed in the data. Reference the Final Feature File for further information. No ferry routes or terminals exist for this survey.No abnormal seafloor and/or environmental conditions exist for this survey.No present or planned construction or dredging are known to exist within the survey limits.No new surveys or further investigations are recommended for this area.No new insets are recommended for this area.As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed the attached survey data and reports.All field sheets, this Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch.The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Field Procedures Manual, Letter Instructions, and all HSD Technical Directives. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required with the exception of deficiencies noted in the Descriptive Report.