California State University, Monterey Bay Digital Commons @ CSUMB State and Federal Documents Relating to Salinas River and Carmel River Groundwater Monterey and San Luis Obispo Counties Basins 7-19-2017 2015, November - Salinas River Salt Modeling Report , Tetra Tech for California Central Coast Regional Water Quality Control Board and US Environmental Protection Agency, Region IX Follow this and additional works at: https://digitalcommons.csumb.edu/hornbeck_cgb_1 Part of the Business Commons, Education Commons, Engineering Commons, Life Sciences Commons, Physical Sciences and Mathematics Commons, and the Social and Behavioral Sciences Commons Recommended Citation "2015, November - Salinas River Salt Modeling Report , Tetra Tech for California Central Coast Regional Water Quality Control Board and US Environmental Protection Agency, Region IX" (2017). State and Federal Documents Relating to Monterey and San Luis Obispo Counties. 14. https://digitalcommons.csumb.edu/hornbeck_cgb_1/14 This Report is brought to you for free and open access by the Salinas River and Carmel River Groundwater Basins at Digital Commons @ CSUMB. It has been accepted for inclusion in State and Federal Documents Relating to Monterey and San Luis Obispo Counties by an authorized administrator of Digital Commons @ CSUMB. For more information, please contact [email protected]. Salinas River Watershed Area Salt Modeling Prepared for California Central Coast Regional Water Quality Control Board US Environmental Protection Agency, Region IX Prepared by One Park Drive, Suite 200 • PO Box 14409 Research Triangle Park, NC 27709 November 2015 (This page left intentionally blank.) Salinas River Watershed Area Salt Modeling November 2015 Contents 1 Introduction ...................................................................................................................1 1.1 Watershed Description ......................................................................................................................1 1.1.1 Project Area ...............................................................................................................................1 1.1.2 Hydrology ..................................................................................................................................4 1.1.3 Climate .......................................................................................................................................7 1.1.4 Land Use/Land Cover .............................................................................................................. 16 1.1.5 Soils ......................................................................................................................................... 19 1.1.6 Geology ................................................................................................................................... 26 2 Impairments and Listings ...........................................................................................39 3 Data Inventory ............................................................................................................43 3.1 Key Data Sources ............................................................................................................................ 43 3.2 Hydrology ....................................................................................................................................... 45 3.2.1 Surface Water .......................................................................................................................... 45 3.2.2 Groundwater ............................................................................................................................ 48 3.3 Water Quality .................................................................................................................................. 48 3.3.1 Surface Water Quality ............................................................................................................. 48 3.3.2 Groundwater Quality ............................................................................................................... 52 3.4 Other Data ....................................................................................................................................... 55 4 Reports/Studies Inventory ..........................................................................................57 4.1 Report Summaries ........................................................................................................................... 57 5 Data Analysis ..............................................................................................................65 5.1 Summary of Hydrology and Water Quality Data ............................................................................ 65 5.1.1 Hydrology: Surface Water ....................................................................................................... 65 5.1.2 Hydrology: Groundwater ......................................................................................................... 69 5.1.3 Water Quality: Surface Water .................................................................................................. 76 5.1.4 Water Quality: Groundwater.................................................................................................. 102 5.2 Analysis of Water Quality Excursions .......................................................................................... 109 6 Conceptual Model Development ..............................................................................119 6.1 Mass Balance of Basin Inflows and Outflows ............................................................................... 126 7 Tool Development ....................................................................................................129 7.1 Structure of the Salt Tool .............................................................................................................. 129 7.2 Model Components and Data Sources .......................................................................................... 135 7.2.1 Land Use/Land Cover Data ................................................................................................... 136 Tetra Tech i Salinas River Watershed Area Salt Modeling November 2015 7.2.2 Meteorology ........................................................................................................................... 139 7.2.3 SaltMod ................................................................................................................................. 141 7.2.4 USGS SPARROW Estimates for Undeveloped Land ........................................................... 155 7.2.5 EnviroAtlas ............................................................................................................................ 157 7.2.6 Impervious Area Runoff and Concentration .......................................................................... 158 7.2.7 Salt Tool Construction and Calibration ................................................................................. 160 8 Model Tool Results ...................................................................................................169 8.1 Annual Summary ........................................................................................................................... 169 8.2 Reach Concentrations .................................................................................................................... 174 8.3 Unit Area Crop Summaries ........................................................................................................... 177 9 Salt Source Analysis .................................................................................................181 9.1 Undeveloped Land ........................................................................................................................ 181 9.2 Land Upstream of Bradley ............................................................................................................ 181 9.3 Agricultural Land .......................................................................................................................... 182 9.4 Urban Land .................................................................................................................................... 185 9.5 Loads Infiltrated from Streams to the Aquifer .............................................................................. 187 9.6 Loads Exported from the Salinas River Watershed Area .............................................................. 188 9.7 Other Wastewater Sources ............................................................................................................ 188 9.7.1 Municipal and Industrial Percolation Ponds and Land Application....................................... 188 9.7.2 Septic System Loads .............................................................................................................. 189 9.8 Atmospheric Deposition ................................................................................................................ 190 9.9 Summary ....................................................................................................................................... 190 10 Recommendations .....................................................................................................195 11 References ...............................................................................................................197