REPLY TO DISCUSSION 'Meadow Restoration Increases Base Flow and Groundwater Storage in the Sierra Nevada Mountains of California'

摘要

In the Discussion, Nash et al. (2019) estimate the seasonal change in groundwater volume for a portion of the restored Sierra Nevada Meadow that we evaluated (Hunt et al. 2018) and use this estimate as an upper bound on the possible contribution to flow that is attributable to restoration. The authors conclude that raising the channel bed elevation and reconnecting the meadow floodplain most likely reduced summer streamflow. In contrast, we report at least a fivefold increase in baseflow from the meadow in the years following restoration. In addition, we observed that, after restoration, the previously intermittent stream below the meadow flowed continuously throughout the summer months, despite record drought conditions, and in 2015, the lowest snowpack on record. We suggest that the groundwater budget presented in the Discussion may not adequately represent conditions within the meadow because the authors extrapolate from 5 near-channel groundwater wells across 62 ha of meadow and assume an area of influence that is approximately one-sixth of the meadow area. We conclude that the conversion of an intermittent stream to perennial flow during drought conditions is a stronger check on our gauge data than the groundwater budget presented in the Discussion.