Publication Date

Fall 2025

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Geology

Advisor

Emmanuel Gabet; Emilio Grande; Nathaniel Bogie

Abstract

Coastal watersheds in California are increasingly affected by climatic variability, threatening stream behavior, ecological function, and salmonid habitat suitability. This study evaluated streamflow behavior of seven watersheds in Marin County, California, with detailed analysis of Corte Madera, Olema, and Redwood watersheds, which are not influenced by reservoir releases. Using USGS stream gauge records, PRISM climate data, SSURGO soils, and geologic and vegetation information, streamflow metrics critical to salmonid life cycles were quantified for water years 2014 to 2023. Watersheds with greater storage capacity, such as Redwood, exhibited muted hydrologic responses, including delayed flow activation, lower peak flows, slower recession rates, and more consistent baseflows, resulting in more stable flow regimes that support salmonid habitat. In contrast, Olema displayed a flashier response characterized by earlier activation, steeper recessions, higher peak flows, and higher runoff ratios, conditions that reduce habitat reliability. Although Olema has deeper bedrock and higher soil water storage, its behavior suggests that geologic structure, subsurface permeability, and drainage density can outweigh expectations based on soil depth or lithology. These results demonstrate that watershed behavior must be interpreted within a regional context. Even watersheds underlain by similar Franciscan Mélange geology can vary widely due to local structure, weathering, vegetation, and drainage network characteristics. A critical zone perspective is necessary for salmonid habitat restoration and water resource management under climate variability.

Download

Included in

Geology Commons

Share

COinS