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Since the 1987 Clean Water Act Section 319 amendment, the US Government has required and funded the development of nonpoint source pollution programs with about $5 billion dollars. Despite these expenditures, nonpoint source pollution from urban watersheds is still a significant cause of impaired waters in the United States. Urban stormwater management has rapidly evolved over recent decades with decision-making made at a local or city scale. To address the need for a better understanding of how stormwater management has been implemented in different cities, we used stormwater control measure (SCM) network data from 23 US cities and assessed what physical, climatic, socioeconomic, and/or regulatory explanatory variables, if any, are related to SCM assemblages at the municipal scale. Spearman’s correlation and Wilcoxon rank-sum tests were used to investigate relationships between explanatory variables and SCM types and assemblages of SCMs in each city. The results from these analyses showed that for the cities assessed, physical explanatory variables (e.g. impervious percentage and depth to water table) explained the greatest portion of variability in SCM assemblages. Additionally, it was found that cities with combined sewers favored filters, swales and strips, and infiltrators over basins, and cities that are under consent decrees with the Environmental Protection Agency tended to include filters more frequently in their SCM inventories. Future work can build on the SCM assemblages used in this study and their explanatory variables to better understand the differences and drivers of differences in SCM effectiveness across cities, improve watershed modeling, and investigate city- and watershed-scale impacts of SCM assemblages.

Ecological restoration is a value‐driven process; yet social understanding of restoration lags ecological understanding. Restoration goals are driven by which stakeholders have a voice in the restoration process and their individual goals. While conflict among stakeholder visions has been observed, we lack a multidimensional understanding of these visions, where they overlap, and how they diverge. Focusing on stream restoration on private lands, we asked: (1) How do perspectives on measures of restoration success vary among stakeholders, including contractors and designers, scientists, organizations, and landowners? and (2) How do these groups discuss and navigate these differences? We used a mixed‐method interview and Q‐methodology approach to understand the range of stakeholders' approaches for assessing a successful stream restoration. We asked stakeholders to rank their level of agreement with 33 statements about restoration goals, using these to evaluate perspectives about restoration success. We identified four perspectives on successful stream restoration that varied in: the use of science‐driven criteria, risk tolerance, private property protection, and commitment to restoring streams to a previous state. Notably, contractors used deficit model approaches to communicate with landowners, even for private restoration. Institutional and cultural changes to how we approach restoration, suggested by some of the interviews, may provide paths forward. These include a recognition that all restoration objectives are socially defined, even within and among professionals, and that landowners have important local‐system knowledge. Earlier engagement between all stakeholders involved in restoration may help create mutual understanding across parties and stave off disputes about project objectives or implementation.

Dissolved organic carbon (DOC) concentrations vary among headwaters, with variation typically decreasing with watershed area. We hypothesized that streamflow intermittence could be an important source of variation in DOC concentrations across a small watershed, through (a) temporal legacies of drying on organic matter accumulation and biotic communities and (b) spatial patterns of connectivity with DOC sources. To test these hypotheses, we conducted three synoptic water chemistry sampling campaigns across a 25.5‐km²watershed in south‐eastern Idaho during early spring, late summer, and late fall. Using changepoint analysis, we found that DOC variability collapsed at a consistent location (watershed areas ~1.3 to ~1.8 km²) across seasons, which coincided with the watershed area where variability in streamflow intermittence collapsed (~1.5 km²). To test hypothesized mechanisms through which intermittence may affect DOC, we developed temporal, spatial, and spatio‐temporal metrics of streamflow intermittence and related these to DOC concentrations. Streamflow intermittence was a strong predictor of DOC across seasons, but different metrics predicted DOC depending on season. Seasonal changes in the effects of intermittence on DOC reflected seasonal changes from instream to flowpath controls. A metric that captured spatial connectivity to sources significantly predicted DOC during high flows, when DOC is typically controlled by transport. In contrast, a reach‐scale temporal metric of intermittence predicted DOC during the late growing season, when DOC is typically controlled by instream processes and when legacy effects of drying (e.g., diminished biological communities) would likely affect DOC. The effects of intermittence on DOC extend beyond temporal legacies at a point. Our results suggest that legacy effects of intermittence do not propagate downstream in this system. Instead, snapshots of spatial patterns of intermittence upstream of a reach are critical for understanding spatial patterns of DOC through connectivity to DOC sources, and these processes drive patterns of DOC even in perennial reaches.