Statewide base-flow estimates for Oregon, water years 1980–2023

Base flow, the groundwater contribution to streamflow, is beneficial data for analysis of groundwater-flow systems. This data release includes base-flow estimates and streamflow data for 471 Oregon streamgage sites. Categories of data include: (1) site information, (2) water year estimates of base flow and streamflow, and (3) daily estimates of base flow. Water-year base-flow estimates are considered most reliable; daily estimates are provided for completion and summarization purposes only. Daily discharge (streamflow) data from water years 1980–2023 were obtained from the United States Geological Survey (USGS; https://waterdata.usgs.gov) and the Oregon Water Resources Department (OWRD; https://apps.wrd.state.or.us/apps/sw/hydro_report/) online databases and used to estimate base flow using three methods: low-flow, graphical hydrograph separation (GHS), and chemical hydrograph separation (CHS). Specific conductance (SC) data from continuous SC monitoring at streamgages were obtained from the USGS database and used for CHS base-flow analysis at 15 sites. Data are in .csv file and .txt file format.