Base flow in a creek is primarily contributed by what source?

Base flow in a creek is primarily fed by groundwater contribution. This phenomenon occurs when water from the saturated zone of the soil or aquifers slowly infiltrates into the stream or creek over time. Essentially, groundwater acts as a natural reservoir that maintains flow within the creek during dry periods when there is little to no surface runoff or precipitation.

When rainfalls occur, some of that water is absorbed by the soil and recharge areas, which gradually releases water into the stream as base flow. This process is crucial for sustaining aquatic ecosystems, maintaining water temperature, and ensuring a constant flow in waterways, especially during dry seasons when surface runoff and precipitation are insufficient to contribute to the creek's flow.