<p>Plug and pond is a watershed restoration approach that has demonstrated benefits in terms of increasing water tables and hydrological residence times, and for re-establishing wetland vegetation communities. However, there has been little study of the biogeochemical benefits of plug and pond treatments, especially in terms of the potential to buffer nutrient loads (particularly nitrate) to streams downgradient of treatment areas. Our objective was to conduct a characterization of the redox processes that occur in constructed ponds as part of plug and pond treatments in three watersheds in the Valles Caldera National Preserve in New Mexico, USA. The studied watersheds were subject to gully erosion prior to the plug and pond treatment. One watershed represented an established plug and pond restoration and the other two watersheds had been restored only about six months prior. Detailed geochemical depth profiles using diffusion cells in constructed ponds show that reducing conditions developed within six months in the two newly treated watersheds. The rapid development of strong reducing conditions suggests that even young plug and pond treatments can provide benefits in terms of moderating nutrient loads. This study demonstrates that there are biogeochemical benefits that are coupled with improvements in hydrological processes and wetland vegetation that extend beyond the ponds. The redox characterization approach utilized here is applicable to other types of watershed restorations where an improved understanding of the impacts on biogeochemical dynamics is needed.</p>