Authors

• Michael Tchintcharauli-Harrison – Oregon State University
• Mary Santelmann – Oregon State University
• Roy Haggerty – Oregon State University

Purpose

To further understand the seasonal dynamics of source waters to springs in an urban setting. We evaluate a subwatershed in Portland, OR and investigate the controls of shallow groundwater, runoff, and precipitation in contributing water and potential contaminants such as nitrate , and the impacts of these source waters on water chemistry of an urban stream.

Description

This study will examine the source flows of waters within the Johnson Creek Watershed in Portland, OR. Geochemical and isotopic tracers will be used to distinguish groundwater contributions from other sources and demonstrate the evolution and mixing of source water flows. The data from this project will be used to understand 1.) if precipitation/surface water or groundwater sources are the primary source of streamflow during winter months in saturated areas, 2.) if storm events can be used to distinguish and quantify the relative influence of precipitation or base flow sources on surface waters, and 3.) what isotopic and hydrochemical data can tell us about the hydrologic responses to the system.