Beebee, Robin A. (ORCID: 0000-0002-2976-7294) Knopp, Schyler J. (ORCID: 0000-0002-3750-1373) Dworsky, Karenth L. (ORCID: 0000-0002-3287-6934) Schauer, Paul V. (ORCID: 0000-0001-5529-4649) 20191220 tabular digital data Anchorage, Alaska U.S. Geological Survey, Alaska Science Center Suggested Citation: Beebee, R.A., Knopp, S.J., Dworsky, K.L., Schauer, P.V., 2019, Tabular input/output data and model files for 19 hydraulic models for streambed scour evaluations at selected bridge sites in Alaska, 2016-2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9LUTFHZ https://doi.org/10.5066/P9LUTFHZ This data release includes tabular surveyed and interpolated elevation data, the processed computational mesh, and model output data used in streambed scour evaluations at selected bridge sites in Alaska, 2016-2017. This is a cooperative project with Alaska Department of Transportation and Public Facilities. The methods of deriving these datasets and using them to calculate scour are described in the associated U.S. Geological Survey Scientific Investigations Report https://doi.org/10.3133/sir20195110. The purpose of the hydraulic models and associated input and output data are to derive variables from which to calculate scour around bridge foundations. The surveyed and interpolated elevation points are used to derive the computational mesh. The computational mesh is an input into the hydraulic model, which is used to derive output variables including water surface elevations, velocities, depths, and sediment transport properties of design floods. These output data are then used to estimate streambed scour around selected bridges in Alaska. Finally, scour numbers go into an overall assessment of each bridge’s vulnerability during flood events. 2016 2017 observed Complete None planned -151.8167 -131.7150 65.5291 55.4083 USGS Metadata Identifier USGS:ASC242 ISO 19115 Topic Category InlandWaters Elevation NASA GCMD Earth Science Keyword Thesaurus Terrestrial Hydrosphere Surface Water Floods Rivers/Streams Water Depth Erosion/Sedimentation USGS Thesaurus Hydrology Geomorphology Scour Hydraulic engineering Alexandria Digital Library Feature Type Thesaurus Bridges None Streambed USGS Geographic Names Information System (GNIS) Alaska Willow Creek Wasilla Creek Cottonwood Creek Moose Creek Ward Creek Sawyer Creek Livengood Creek Peters Creek Twin Creek Little Susitna River North Fork Anchor River South Fork Anchor River Ship Creek No access constraints. No use constraints. These data are marked with a Creative Common CC0 1.0 Universal License and are in the public domain. It is requested that this USGS data release be cited for any subsequent publications that reference or utilize these data. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. U.S. Geological Survey, Alaska Science Center Mailing and Physical

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Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov The Alaska Department of Transportation and Public Facilities contributed funding to this project. Survey data were collected by Joseph Dementieff in addition to the authors. Beebee, R.A. Dworsky, K.L. Knopp, S.J. 2019 publication U.S. Geological Survey Scientific Investigations Report 2019-5110 online U.S. Geological Survey Beebee, R.A., Dworsky, K.L., Knopp, S.J., 2019, Streambed scour evaluations and conditions at selected bridge sites in Alaska, 2016–17: U.S. Geological Survey Scientific Investigations Report 2019-5110, 32 p., https://doi.org/10.3133/sir20195110 https://doi.org/10.3133/sir20195110 Surface-water Modeling System (SMS) v13.0 user interface was used to develop the computational mesh and compile the input data for the SRH-2D hydraulic model. An SMS executable is necessary to open and view the model files. https://www.aquaveo.com/downloads-sms?s=SMS&v=13.0 The executable can be downloaded and a free community license can be requested upon installation. Aquaveo mailing and physical

3210 N. Canyon Road

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Provo Utah 84604 +01 801-691-5528 info@aquaveo.com For survey input data, accuracy was evaluated based on total station closure error, standard GPS error, or in the case of soundings, the greatest discrepancy seen in repeat measurements. From these observations, X and Y coordinates have an accuracy of 0.3 feet and Z coordinates have an accuracy of 0.1 feet Accuracy is only relative to the land surface at the time of survey, and most of these points are on streambeds that move. Interpolated coordinates have unknown accuracy. The computational mesh and solutions derived with the model software have lower resolution and therefore more uncertainty than data surveyed in the field. The interpolated mesh and interpolated survey point surface were graphically compared within SMS to identify major deviations, but no formal attempt was made to determine the accuracy of the computational mesh relative to the survey points. At eight sites, model output water surface elevations and velocity were verified with measured values. The verification results show water surface differences of -0.2 to 0.3 feet and velocity differences of -0.3 to 0.1 ft/s between the survey and the model simulations. The accuracy of the model results for the 100 and 500-year floods is unknown, and any use of these results requires an understanding of the uncertainty and limitations in estimating design floods and in deriving variables with two-dimensional hydraulic modeling. These models were developed for the specific purpose of estimating the potential for streambed scour around the bridges, thus model resolution is generally greater immediately around the bridges of concern and both resolution and accuracy diminish near the model domain boundaries. Data values are consistent with no gaps. Model output points with null values, such as depth outside the flooded area, have the numerical code "-999". Data points were omitted that were not used for the model, such as survey points on the bridge used to tie in elevations. Positions are reported to one tenth of a foot. Survey positions are assumed to be accurate to about 0.3 feet based on maximum backsight closure error and observations of repeat soundings along taglines. No horizontal accuracy is claimed for interpolated points, the computation mesh or model output variables. Alaska Division of Geological and Geophysical Surveys Matanuska-Susitna Borough U.S. Geological Survey Municipality of Anchorage Kenai-Peninsula Borough State of Alaska Ketchikan Borough Federal Emergency Management Agency 20191202 application/service Fairbanks, Alaska Alaska Division of Geological and Geophysical Surveys The webpage is updated as additional lidar is submitted and processed. https://elevation.alaska.gov/ Digital and/or Hardcopy 2008 2011 2014 2018 ground condition Lidar The Alaska Division of Geological and Geophysical Surveys serves publicly available lidar datasets in Alaska. Many of these datasets provided floodplain elevations used in the computational mesh in the hydraulic model. Beebee, R.A. Dworsky, K.L. Knopp, S.J. 2019 publication U.S. Geological Survey Scientific Investigations Report 2019-5110 online U.S. Geological Survey Beebee, R.A., Dworsky, K.L., Knopp, S.J., 2019, Streambed scour evaluations and conditions at selected bridge sites in Alaska, 2016–17: U.S. Geological Survey Scientific Investigations Report 2019-5110, 32 p., https://doi.org/10.3133/sir20195110 https://doi.org/10.3133/sir20195110 publication 2019 publication date Beebee and others, 2019 This publication explains the hydraulic modeling process and derivation of other input variables to the hydraulic model. Aquaveo, Inc. 20190310 application/service SMS SRH-2D 13.01 online Aquaveo, Inc. https://www.aquaveo.com/downloads-sms?s=SMS&v=13.0 Digital and/or Hardcopy 20190310 publication date SMS The SMS user interface was used to develop the computational mesh and compile the input data for the SRH-2D hydraulic model Yong G. Lai 201602 application/service SRH-2D Version 2.2 Denver, Colorado U.S. Bureau of Reclamation https://www.usbr.gov/tsc/techreferences/computer%20software/models/srh2d/index.html Digital and/or Hardcopy 200811 201602 publication date SRH-2D The SRH-2D model was used within SMS to calculate output hydraulic variables including water surface elevation and velocity. METHODS: Elevation points were surveyed along the upstream and downstream faces of bridges and as cross-sections upstream and downstream of the bridge. Multiple instruments (total station, GPS, ADCP, level and tagline) were used at most sites. All coordinate points were adjusted to a common datum (usually NAVD88) and merged in a GIS. Points were interpolated between survey points using the GIS or HEC-RAS in order to create a smooth bathymetric surface. SMS software is used to triangulate between bathymetric and lidar input points to make a surface, then overlay a lower-resolution geometric mesh on this triangulated surface for the purposes of computing hydraulic variables. The computational mesh may include voids that replace steep or vertical surfaces. SMS then uses the computational mesh, in addition to inputs outlined in Beebee and others, 2019, and SRH-2D, to derive hydraulic output variables for flood events. Unknown Point State Plane Coordinate System 1983 5004 0.999 -150.00 54 1640416.666666667 0 coordinate pair 0.6096 0.6096 survey feet North American Datum of 1983 (NAD83) Geodetic Reference System of 1980 (GRS80) 6378137 298.257222101 North American Vertical Datum of 1988 (NAVD83) 0.1 feet Explicit elevation coordinate included with horizontal coordinates [FOLDER] (SiteNameSiteNumber)_Bathymetry.csv Zipped folder containing 19 tables with surveyed and interpolated bathymetric data used to produce the computational mesh. Presented in a Comma Separated Value (CSV) formatted table. Author defined X The Easting (state plane) of surveyed or interpolated point in feet. Author defined 1763516.8 1763689.0 feet 0.1 Y Northing (state plane) of surveyed or interpolated point in feet. Author defined 2780228.5 2780418.0 feet 0.1 Z Elevation of surveyed or interpolated point in feet. Author defined -9.6 576.3 feet 0.1 Source "Survey" points were surveyed in the field using level and tagline, total station, GPS, and/or ADCP methods. "Interpolated" points were added between survey points using a GIS to produce a smooth transition between cross-sections. Author defined survey ground point surveyed in field Author defined interpolation Points interpolated between ground points in a GIS to create a smooth channel surface Author defined [FOLDER] (SiteNameSiteNumber)_Model_Input_Output.csv Zipped folder containing 19 table with mesh element point locations. Mesh coordinates were derived using SMS software, surveyed bathymetry data and publicly available lidar data. Presented in a Comma Separated Value (CSV) formatted table. Author defined X Easting (State Plane) of the mesh element point location. The mesh (X, Y, and Z) was derived using SMS software, surveyed bathymetry data and publicly available lidar data, which is cited in the larger work. Author defined 1762574.6 1764050.8 feet 0.1 Y Northing (State Plane) of mesh element point location. The mesh (X, Y, and Z) was derived using SMS software, surveyed bathymetry data and publicly available lidar data, which is cited in the larger work. Author defined 2779636.5 2780944.9 feet 0.1 Z Ground elevation of each mesh element. The mesh (X, Y, and Z) was derived using SMS software, surveyed bathymetry data and publicly available lidar data, which is cited in the larger work. Author defined -9.3 387.2 feet 0.1 WSE100 Water surface elevation from the 100-year flood simulation at mesh element. Author defined 1.9 377.4 feet 0.1 V100 Water velocity from 100-year flood simulation at mesh element. Author defined 0 8.4 feet 0.1 CRITICALV100 Critical velocity (velocity at theoretical threshold for sediment transport) from 100-year flood simulation at mesh element. Author defined 0 8.1 feet 0.1 WSE500 Water surface elevation from 500-year flood simulation at mesh element. Author defined 1.9 650.0 feet 0.1 V500 Water velocity from 500-year flood simulation at mesh element. Author defined 0 13.5 feet 0.1 CRITICALV500 Critical velocity (velocity at theoretical threshold for sediment transport) from 500-year flood simulation at mesh element. Author defined 0 8.2 feet 0.1 [FOLDER] (SiteNameSiteNumber).sms Zipped folder containing 19 folder with an SRH2D model is provided for each site in the study. The zipped model folder contains all files necessary to open and view the model as an alternative way to see input and output data. An SMS executable is necessary to open and view the model files. The executable can be downloaded at https://www.aquaveo.com/downloads-sms?s=SMS&v=13.0 and a free community license can be requested upon installation. Author defined U.S. Geological Survey USGS ScienceBase Team Mailing and Physical

Denver Federal Center, Building 810, Mail Stop 302

Denver Colorado 80225 USA 1-888-275-8747 sciencebase@usgs.gov The U.S. Geological Survey, Alaska Science Center is the authoritative source of these data, distributed by ScienceBase (a USGS Trusted Digital Repository). Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data for other purposes or on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. CSV, ASCII, SMS 19.0 7Zip utility used for packaging. Tabular data in CSV and ASCII formats; Model data in a proprietary SMS format; metadata in XML and HTML formats. https://doi.org/10.5066/P9LUTFHZ None SMS software will be necessary to view the model files in sms format. 20250514 U.S. Geological Survey, Alaska Science Center Mailing and Physical

4210 University Drive

Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov FGDC Content Standard for Digital Geospatial Metadata (CSDGM) FGDC-STD-001-1998