ABSTRACT:

Surface water presence and absence data for "Diminishing influence of catchment properties on network-scale surface water persistence during a multi-year drought" by Giggy, Price, and Zimmer, 2025.
Stream networks display dynamic patterns of surface water wetting and drying that strongly influence ecological function and downstream water quality. While topography and subsurface properties play important roles in surface water persistence, it is unclear how sensitive non-perennial stream networks are to persistent or severe drought conditions. To address these challenges, we monitored hourly surface water presence and absence for three consecutive drought years at 31 locations across a 0.25 km2 non-perennial headwater stream network in central coastal California. We coupled these observations with landscape characteristics and weather station data to examine both physical and climatic drivers of surface water activation and persistence. We observed declining spatial variability in surface water persistence and declining correlations between persistence and physical landscape attributes with ongoing drought. Unlike prior years, flow activation events in the final study year were more closely associated with precipitation event characteristics than antecedent storage states. This may suggest shifts from storage-threshold related runoff mechanisms to intensity-threshold runoff mechanisms. These results have important implications for water availability, ecological refugia, and our ability to predict spatiotemporal changes in surface water across headwater systems under changing climate.

ABSTRACT:

Data associated with Giggy and Zimmer (2025). The role of lithology on concentration-discharge relationships and carbon export in two adjacent headwater catchments.

ABSTRACT:

This resource contains steam discharge time series from the 2021 and 2022 water years at North and South Dark Canyon watershed outlets. These watersheds are located in UC Berkeley's Blue Oak Ranch Reserve and are monitored for ongoing research conducted by the Zimmer Watershed Hydrology Lab at UC Santa Cruz.