Merrick-Surdex Joint Venture, LLP 20200807 vector digital data Hydro-flattened breaklines were compiled and followed the Quality Level Two (QL2) standards as outlined in the USGS-NGP Lidar Base Specifications, Techniques and Methods Chapter 4 of Section 5, Version 2.1, October 2019. Rivers greater than 100 feet wide and waterbodies larger than 2 square acres. This project will support the 3DEP mission, the Federal Emergency Management Agency (FEMA) Risk Mapping, Assessment and Planning (MAP) program and the Natural Resources Conservation Service (NRCS) high resolution elevation enterprise program. The entire AOI covers approximately 8,964 square miles in total in Northeast Nebraska delivered in UTM Zone 14 coordinate system. This project is broken into three delivery blocks. The following block square miles are approximations: Block1 = 4492, Block2 = 2964, Block3 = 1508. Breakline File Type = GDB Breakline Elevation Units = Meters Downhill Treatment Applied = Monotonic Type of Hydro Treatment Required = Hydro-flattened 20200418 20200426 ground condition Complete Unknown -97.520827 -97.116289 42.891196 41.734899 623000.000000 654000.000000 4750000.000000 4622000.000000 None Breaklines Elevation Data Lidar None Northeast Nebraska No restrictions apply to these data. None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data. Data covers the entire area specified for this project. Hydro breaklines were collected in all inland ponds and lakes ~2 acres or greater. These features were flat and level water bodies at a single elevation for each vertex along the bank. The entire water surface edge is at or below the immediate surrounding terrain. Breaklines were collected for all streams and rivers ~100' nominal width or wider. These features are flat and level bank to bank, gradient will follow the surrounding terrain and the water surface will be at or below the surrounding terrain. Streams/river channels will break at culvert locations however not at elevated bridge locations. Depending on the situation some under bridge breaklines might be necessary so that water flows underneath these bridge locations. The dataset was reviewed to ensure completeness and accuracy. Using MARS software hydro-flattened breaklines (rivers greater than 100 feet wide and waterbodies greater than two square acres) were compiled. Some bridges could potentially need breaklines placed under them so that water will flow properly. Using intensity values and 3d elevations generates ESRI shape files which are then imported into an ESRI gdb for a project-wide delivery. Monotonicity checks where validated (water flowing downstream). 20200805 Vector Universal Transverse Mercator 14 0.9996 -99.000000 0.000000 500000 0 coordinate pair 0.001 0.001 meters D_NAD_1983_2011 Geodetic Reference System 80 6378137.000000 298.257222 North American Vertical Datum of 1988 Geoid2018 0.001 meters Explicit elevation coordinate included with horizontal coordinates 20200808 Merrick-Surdex Joint Venture, LLP mailing and physical address

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