Preliminary Estimations

When preparing for water-related fieldwork or project development, it is often helpful to have advanced knowledge of site hydrology including weather, stream discharge, stage, etc. This portion of the website contains hydrologic estimations for the major basins in Oregon. The estimations provided include:

• Discharge per square mile of basin area
• Range for average annual precipitation over the basin
• Percentage of annual basin flow occuring in each month

To access this information simply click on the name of the basin of interest in the map below (map provided by the Oregon Water Resources Department).