2024 Oregon Williamson Basin Groundwater Study Data

Groundwater is becoming increasingly more important in the Pacific Northwest of the USA due to declining snowpack volumes and shifts in both precipitation type and timing that is connect-ed to climate change. The Upper Williamson Basin, of the Klamath Watershed, is a groundwater dominated watershed that has seen massive fluctuations in year-to-year streamflow volumes over the past four decades, including the complete absence of any live flow for several years. The precise relationship between groundwater and streamflow in the basin has been difficult to assess due to a limited number of monitoring wells and significant gaps in the water level time history. To address this challenge, we use a novel imputation technique that leverages Earth observations and machine learning to impute gaps in water level records and we use these more complete datasets to develop a groundwater storage change time series for the basin. We show that overall groundwater storage is highly correlated to streamflow and that groundwater storage is correlated to rainfall with a three-year delay. These tools and relationships make it possible for water managers to estimate when streamflows will return to the basin.

In this data archive, we provide a copy of the monitoring well data used in the study including the names and locations of the wells and the corresponding historical groundwater levels measured at the wells. We also provide a copy of the basin boundary.