Dina K. Saleh Charles N. Alpers 20250609 tabular digital data Reston, VA U.S. Geological Survey https://doi.org/10.5066/P1MHGVGR Dina K. Saleh Charles N. Alpers 2024 publication University of California, Davis - Tahoe Environmental Research Center (UCD - TERC) University of California, Davis In: A. Cortés, M. Swann, S. A. Valbuena, M. W. Terrell, S. Sharp, K. Pinkanjananavee, R. Thirkill, N. T. Framsted, A. M. Liston, S. M. Sesma, K. C. Martinez, A. L. Vanderpool, L. Vaughan, E. W. Young, M. Cane, S. Watanabe, S. Sadro, A. L. Forrest, S.G., 2024, Schladow, Clear Lake Watershed and Lake Remediation https://clearlakerehabilitation.ucdavis.edu/sites/g/files/dgvnsk12236/files/inline-files/ClearLakeRehabilitation_FINAL_REPORT_0.pdf Models of daily mass loads of nutrient species constituents and suspended sediment at tributary locations using water quality measurements and stream discharge from river gauging stations were developed to estimate nutrient and suspended sediment mass loads flowing into the Clear Lake watershed. Mass loads are calculated by multiplying stream discharge, measured as volume per time, by constituent concentration, measured in mass per volume. River Load Estimation (rloadest) models were used to complete a regression analysis of the natural logarithm of nutrient concentration as a function of either flow, the square of flow, decimal time, seasonality, or some combination of these terms. The code for rloadest in R is available at: (Lorenz and others, 2017). Rloadest models of daily concentration and daily loads were attempted for the nutrient constituents, and suspended sediment, at 10 sites in the Clear Lake watershed. Rloadest model output includes the daily predicted concentration, in milligrams per liter, and the daily predicted mass load, in kilograms of constituent per day. Loads are aggregated by the model so that monthly or yearly loads are also calculated. This USGS data release contains all of the input and output files needed to reproduce the model results described in Chapter 6.1 LOADEST Modeling of nutrient and sediment concentrations and loads, In: A. Cortés, M. Swann, S. A. Valbuena, M. W. Terrell, S. Sharp, K. Pinkanjananavee, R. Thirkill, N. T. Framsted, A. M. Liston, S. M. Sesma, K. C. Martinez, A. L. Vanderpool, L. Vaughan, E. W. Young, M. Cane, S. Watanabe, S. Sadro, A. L. Forrest, S.G., 2024, Schladow, Clear Lake Watershed and Lake Remediation 20160101 20240501 observed Complete None planned Clear Lake, Lake County, California -123.0976 -122.5688 39.3207 38.8020 ISO 19115 Topic Category biota USGS Thesaurus Nutrient loads modeling Analysis nutrient content (water) water quality water chemistry USGS Metadata Identifier USGS:6744cac1d34eacadb5a4b173 USGS Common Geographic Areas thesaurus California Clear Lake Lake county None. Please see 'Distribution Information' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. It is requested that the suggested citation for this USGS data release be included in any publications that reference or utilize these data. Dina K. Saleh USGS - SOUTHWEST REGION Research Hydrologist mailing and physical

California Water Science Center, California District Office - Placer Hall

Sacramento CA 95819 United States 916-278-3273 dsaleh@usgs.gov The preferred method to run the load calculations is using the RStudio (version: 2024.12.1+563) interface. This is an interface for executing the packages and commands from the R computing framework. Both R and RStudio are required.RStudio for Windows, MacOS, and Linux is available at https://posit.co/download/rstudio-desktop/. The R software (R project for statistical computing) is available at https://www.r-project.org. To install rloadest, it is necessary to use the remotes R package since the rloadest files must be downloaded from GitHub: De Cicco, L.A., Hirsch, R.M., Lorenz, D., Watkins, W.D., Johnson, M., 2024, dataRetrieval: R packages for discovering and retrieving water data available from Federal hydrologic web services, v.2.7.17, https://doi.org/10.5066/P9X4L3GE To install the rloadest package, Open RStudio and in the “Console” window run these commands: options(repos = c( ldeciccousgs = 'https://ldecicco-usgs.r-universe.dev', CRAN = 'https://cloud.r-project.org')) # Install some packages install.packages('rloadest') For all data, no formal accuracy tests were conducted All attributes were checked for outliers and if the data is within the allowed range for the data. All attributes were checked for outliers and if the data is within the allowed range for the data. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted De Cicco, L.A. 2024 tabular digital data https://doi.org/10.5066/P9X4L3GE Digital and/or Hardcopy 2024 publication date De Cicco and others, 2024 Model Code Lorenz, D., Runkel, R., De Cicco, L., Watkins, D., and J. Stachelek 2017 tabular digital data Accessed on 05/22/2025 https://github.com/USGS-R/rloadest Digital and/or Hardcopy 2017 Lorenz and others, 2017 RLoadest Coade used to calculate daily nutrient and suspended sediment loads Sushch, D. 2025 tabular digital data Digital and/or Hardcopy 2025 Sushch and others, 2025 Water-quality data USGS 2024 tabular digital data https://doi.org/10.5066/F7P55KJN Digital and/or Hardcopy 2024 U.S. Geological Survey, 2024 Water Quality Nutrient data The dataRetrieval package was created to simplify the process of loading hydrologic data into the R environment. It is used to retrieve the major data types of U.S. Geological Survey (USGS) hydrology data that are available on the National Water Information System (NWIS). More information is available in the ReadME_LOADEST.txt file related to this data release. De Cicco and others, 2024 2024 Rloadest—River Load Estimation: R package version 0.4.5, This code was used in R to estimate nutrients and suspended sediment concentrations and loads for the 10 sites in the Clear Lake watershed on a daily and monthly time step. More information is available in the ReadME_LOADEST.txt file related to this data release. Lorenz and others, 2017 2017 Water-quality data collected at ten gaging stations in the Clear Lake watershed, Lake County, CA. This data was used to calibrate the rloadest models developed to estimate daily and monthly mass loads for nutrients and suspended sediment. More information is available in the ReadME_LOADEST.txt file related to this data release. Sushch and others, 2025 USGS water data for the Nation: U.S. Geological Survey National Water Information System (NWIS) database. This dataset provided nutrient and suspended sediment concentrations as well as daily stream flow data used to develop the rloadest models. More information is available in the ReadME_LOADEST.txt file related to this data release. U.S. Geological Survey, 2024 2024 Albers Conical Equal Area 29.5 -96.0 23.0 0 0 coordinate pair 0.01 0.01 meters North American Datum of 1983 (NAD 83) Geodetic Reference System 1980 6378137.000000 298.257222 ClearLake_Loadest_Data_Dictionary.csv Comma Separated Value (CSV) defining data contained in the ClearLake_loadest_Sites.zip folder need to run the RLOADEST model Producer Defined Entity Folder name Producer Defined << empty cell >> No Data Producer defined Name of folder with all the data needed to run the model. There are 10 sub-folders within the main project folder one for each of the 10 sites in the study area. Each site folder contains a number of constituent folders that hold all the files that are needed to run the RLOADEST model. These files are: 1) input files: Daily flow data file, constituents files. 2)output files: for estimated daily concentrations, and estimated daily loads. Data Type file type, input or output data Producer Defined << empty cell >> No Data Producer defined file type, input or output data files Attribute Attribute Name Producer Defined << empty cell >> No Data Producer defined Attribute Name in each input or output file Attribute Definition text of attribute definition Producer Defined definition of attribute in the input and output files Attribute Definition Source Source of the data Producer Defined << empty cell >> No Data Producer defined Source of information in the files Range - Minimum value of minimum range of data Producer Defined << empty cell >> No Data Producer defined value of minimum range of data Range - Maximum value of maximum range of data Producer Defined << empty cell >> No Data Producer defined value of maximum range of data Range - Units Constituent unit Producer Defined Constituent unit. Date must be defined as Year-Month-Day (yyyy-mm-dd) ClearLake_loadest_Sites.zip Compressed folder that contains all the files needed to run the model for the 10 sites in the study. Each site folder includes sub-folders of the constituent modeled using rloades. More information is available in the ReadMe_LOADEST file. Producer Defined ClearLake_Loadest_Data_Dictionary.csv: Comma Separated Value (CSV) defining data contained in the ClearLake_loadest_Sites.zip folder need to run the rloadest model. ClearLake_loadest_Sites.zip: Compressed folder that contains all the files needed to run the model for the 10 sites in the study. Each site folder includes sub-folders of the constituent modeled using rloades. More information is available in the ReadMe_LOADEST file. NA GS ScienceBase U.S. Geological Survey - ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov 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 (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P1MHGVGR None 20250609 Dina K. Saleh USGS - SOUTHWEST REGION Research Hydrologist mailing and physical

California Water Science Center, California District Office - Placer Hall

Sacramento CA 95819 United States 916-278-3273 dsaleh@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999