A potential engineering solution to facilitate upstream movement of fish in mountain rivers with weirs:Southern Carpathians,the Azuga River

An important aspect in the restoration of longitudinal connectivity in rivers and streams is the implementation of fish migration systems at the upstream of the functional hydraulic structures(weirs,drop structures or river sills).The diversity of these existing structures as well as the different locations of these weirs within the river,watershed and riparian zone challenge the design engineers to find new holistic solutions for fish migration systems.The Azuga River study area requires a new synergistic fish migration design system.Being a mountain area,rapid increase in water level is quite frequent,especially after heavy or prolonged rainfalls and during spring snow melt.Therefore,it is necessary to design a specific system for fish migration to meet this location’s requirements.Due to the characteristics in this location of the Azuga river,the classic fish migration systems would not be functional.The indigenous/mountain trout is considered as the target species in this paper.Although this is a good swimming species,the use of classical systems could,due to exhaustion,prevent and/or reduce the movement of fish upstream of the two weirs(also known as river sills).This new,comprehensive solution,presented in this paper includes:(i)the restoration and stabilization works of the right bank in the weir study area by using biotechnical measures and(ii)the upstream migration system itself-for supporting the migration of fish on the Azuga River.

Turkey Creek—A Case Study of Ecohydrology and Integrated Watershed Management in the Low-Gradient Atlantic Coastal Plain, USA

Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studies can provide needed context for addressing complex spatial and temporal dynamics of these functions and services. This study was conducted on the 5240 ha Turkey Creek watershed (WS 78) draining a 3rd order stream on the Santee Experimental Forest within the South Carolina Atlantic Coastal Plain, USA. The study objectives were to present the hydrologic characteristics of this relatively undisturbed, except by a hurricane (Hugo, 1989), forested water-shed and to discuss key elements for watershed management, including water resource assessment (WRM), modeling integrated water resources management, environmental assessment, land use planning, social impact assessment, and information management. Runoff coefficients, flow duration curves, flood and low flow frequency curves, surface and ground water yields were assessed as elements of the WRM. Results from the last 10 years of interdisciplinary studies have also advanced the understanding of coastal ecohydrologic characteristics and processes, water balance, and their modeling including the need of high resolution LiDAR data. For example, surface water dynamics were shown to be regulated primarily by the water table, dependent upon pre- cipitation and evapotranspiration (ET). Analysis of pre- and post-Hugo streamflow data showed somewhat lower but insignificant (α = 0.05) mean annual flow but increased frequency of larger flows for the post-Hugo compared with the pre-Hugo level. However, there was no significant difference in mean annual ET, potentially indicating the resiliency of this coastal forest. Although the information from this study may be useful for comparison of coastal ecohydrologic issues, it is becoming increasingly clear that multi-site studies may be warranted to understand these complex systems in the face of climate change, sea level rise, and increasing development in coastal regions.