Quantifying the effects of watershed improvement efforts is critical to agencies responsible for protecting water resources of the semiarid western United States. A complex water quality data set collected from 1994 to 2004 of upper Muddy Creek Basin was subjected to cluster analysis, discriminant analysis, and canonical correlation analysis to improve understanding of basin fluvial processes and to investigate whether livestock grazing best-management practices (BMPs) improved the water quality of the watershed. Hierarchical agglomerative cluster analysis grouped nine sampling sites into two clusters based on similarity of biological indices, separating the clusters into aquatic communities more and less tolerant of degraded stream conditions. Discriminant analysis yielded strong spatial and temporal distinctions, providing important data reduction by rendering seven key parameters (total dissolved solids [TDS], temperature, elevation, slope, 10-dominant taxa, percent collector-gatherers, and percent Plecoptera) for the spatial variation and four parameters (TDS, dissolved oxygen, total taxa, and community tolerance quotient) for the temporal variation. Canonical correlation analysis identified strong negative relationships among Plecoptera taxa and total taxa with TDS and turbidity in addition to strong positive associations with elevation, slope, and channel substrate weighted embeddedness value. Despite the onset of severe drought midway through the study period, overall reductions of 13% for TDS and a 30% increase in macroinvertebrate total taxa occurred across years, strongly suggesting that improvements in water quality were correlated to BMPs that stabilized stream channels and improved the condition of riparian areas. Resumen La cuantificación del efecto de esfuerzos de mejoramiento de las cuencas hidrológicas es crítico para las agencias responsables de la protección de los recursos hídricos del oeste semiárido de los Estados Unidos. Un complejo base de datos de la calidad del agua de la parte superior de la Cuenca Muddy Creek Basín, colectados de 1994 a 2004, fue sujeto a un análisis de cuadrante, análisis discriminado y análisis de correlación, para mejorar el entendimiento del proceso fluvial de la cuenca, así como para investigar si las mejores prácticas de manejo (BMPs) del pastoreo del ganado, mejoran la calidad del agua de la cuenca. El análisis grupal jerárquico de aglomeración, agrupó nueve sitios de muestreo en dos cuadrantes, basados en la similitud de índices biológicos, separando los grupos dentro de comunidades acuáticas de mayor y menor tolerancia a las condiciones de degradación por la corriente. El análisis de discriminación produjo distinciones espaciales y temporales más fuertes, proporcionando importantes reducciones de datos por representación de siete parámetros claves (disolución de sólidos totales [TDS], temperatura, elevación, pendiente, porcentaje de las 10 dominantes taxa, porcentaje de colector-recolector y porcentaje de plecóptera) para la variación espacial, y cuatro paráme...

Understanding the complex relationships among land use, geology, and climate in semiarid watersheds is essential to restoring degraded riparian areas and improving water quality. Muddy Creek in south-central Wyoming has been listed as impaired since 1996 by the US Environmental Protection Agency due to unstable stream channels and degraded riparian habitat. Water quality data collected from 1985 to 2006 were used to determine trends in surface-water quality. Flow analyses identified reductions in percents of flow duration intervals between the impaired stream's upper and lower boundary monitoring sites and in hydrograph peaks between pre-and post-best management practice (BMP) implementation. Following BMP implementation, reductions in specific conductivity, total dissolved solids, and turbidity among years were observed in the impaired stream section. Linking water quality improvements to specific BMPs is difficult; however results strongly suggest that positive trends are correlated to BMPs that stabilized stream channels and improved the condition of riparian areas. Naturally erosive conditions in the basin along with anthropogenic impacts elevate the importance of BMP implementation and a long-term monitoring program. Both are needed to evaluate the effectiveness of improvement efforts and to help resource managers develop practical watershed improvement management strategies so that optimum conditions in Muddy Creek basin can be achieved.