During August–September 2012, we sampled six hydropower reservoirs in southeastern United States for CO2 and CH4 emissions via three pathways: diffusive emissions from water surface; ebullition in the water column; and losses from dam tailwaters during power generation. Estimates of average areal emission rates of CO2 attributable to the six reservoirs (i.e., reservoir plus tailwater emissions)...

The organophosphate (OP) insecticides diazinon and chlorpyrifos have been frequently detected in the San Joaquin River, California, USA. Irrigation tail waters are a significant source of OP pesticides in the watershed. This study tested several management practices for reducing offsite movement of chlorpyrifos to surface water from flood irrigated alfalfa. Management practices evaluated includ...

During non-generation periods, leakage through the wicket gates of a hydroturbine often results in very poor quality water (low or zero dissolved oxygen) in the tailrace of the hydropower facility. Generally, the leakage rate is relatively small, usually about 5-10 cfs per turbine. A bottom-mounted diffuser system was designed based on laboratory-measured and manufacturer-supplied specification...

—Eighty-three paddlefish Polyodon spathula that were collected from 1995 to 1999 from the Missouri River Galvins Point Dam tailwater were analyzed for genetic variation in the mitochondrial DNA d-loop region. Additional samples from Montana, South Dakota, and Louisiana were used for comparative purposes. To facilitate the efficient analysis of numerous paddlefish samples, we applied a method th...

The propagation of dam-break waves on different rough beds was observed to be quasi-steady in the range $11.3 < x/h_{dam} 18.8$ , where $x$ is measured from dam position. These speeds converge with steady ideal fluids model Stoker ( Water Waves 1957, Interscience) when tailwater depth $h_2$ becomes greater than ${\sim }0.5k_s$ $0.001< k_s/h_{dam}< 0.2$ $k_s$ roughness and $h_{dam}$ beh...

Dam-break flood waves represent a severe threat to people and properties located in downstream regions. Although dam failure has been among the main subjects investigated academia, little effort made toward investigating wave propagation under influence of tailwater depth. This work presents three-dimensional (3D) numerical simulations laboratory experiments dam-breaks with performed at Laborat...

In this paper, an experimental investigation was carried out to study the turbulent flows and flow characteristics through sloping and adversely sloping rectangular culverts in a rectangular channel of constant width using Laser Doppler Velocimetry (LDV). Also, experimental study was carried out to investigate the characteristics of the hydraulic jump occurring in a sloping and adversely slopin...