Combining Fish Passage and Sediment Bypassing: A Conceptual Solution for Increased Sustainability of Dams and Reservoirs

Abstract

Sedimentation is one of the main eco-morphological and technological challenges associated with reservoirs. Sedimentation not only reduces the functional capacity of a reservoir by filling it, but also changes downstream sediment dynamics and habitat availability for the aquatic biota. Additionally, dams hinder free bi-directional fish passage, emerging as a major threat to species of migratory fish. In the past decades, mitigation measures aimed at reducing such environmental and technological impacts have been developed. Sediment bypass tunnels (SBTs) have been shown to successfully help prevent reservoir sedimentation, whereas fish passages have been found to be potential solutions to facilitate bi-directional passage of fish. However, the construction of such structures, in particular of SBT, can be extremely costly. The development of design solutions that can function both for downstream sediment transport and up- and downstream fish passage should be considered as they can mitigate ecological deficiencies of reservoir operations while accounting for economic feasibility. Possibilities and challenges of combining SBT and fish passage were explored by bringing together a team of interdisciplinary specialists on hydraulics, sediment transport and continuity, bypassing, hydraulic structures, hydropower engineering, aquatic biology, and fish passage in a two-day workshop. Here, we present potential solutions identified during the workshop for integrating SBT and fish passage.

Bioconversion of Bottom Sediments Using Mesophilic Prokaryotes of the Genus Bacillus spp.

“…For staining, a set of dyes was used: "Micro-GRAM-NITSF" (produced by the Research Center for Pharmacotherapy (NITSF), Russia), designed for differential diagnostic staining of microorganisms by sequential processing of a smear taken from biological material with the components of the set: gentian violet, basic fuchsin, Lugol and 96 alcohol. Microscopy was used to assess the presence of bacteria with a gram-positive type of cell wall, stained dark purple with gentian violet [7][8]. Microscopy was performed using immersion technology at magnification ×1000 on a biological microscope "Motic B1-220E-SP" (manufactured in China), equipped with a digital camera "Moticam T" and software "Motic Images Plus 2.0" (manufactured in China) to display an image of the observed object on a computer screen in real time and documenting the obtained results of microscopic examination.…”

Participation of Pseudomonas spp. and Bacillus spp. in the solubilization of silicon, potassium and phosphorus from bottom silt deposits

“…As a substrate for the solubilization of silicon, phosphorus and potassium, bottom silt deposits formed as a result of the activities of rainbow trout farms and selected from a 20-meter depth of the reservoir were used. The formation of bottom silt deposits relates to ecological, morphological and technological problems of fishery water use, reduces the functional capacity of the reservoir, negatively affects the biodiversity of aquatic organisms [7] due to habitat degradation [8; 9]. Bottom silt deposits can be used as a basis for obtaining valuable organic fertilizers for agricultural plants.…”

Review on erosion phenomenon, maintenance, and financial calculation of lifetime as an asset for Pelton turbines

“…The control of sediments and their management in Pelton turbines has been extensively studied for reducing their passage through the turbine [8]. The measurement of sediments passing through power plant facilities becomes more important nowadays and it can be periodical and online [13].…”

“…Due to their impact on river biodiversity, nutrient transport, and spawning habitat disturbances, dams are facing increased regulation by environmental agencies [6,7]. Currently, new dam designs are evaluated considering the management of sediment loads, minimizing their impact on the environment, and respecting the transit of fish, which are under ecological standards being implemented [8]. The capacity of dams around the world is decreasing by about 1% annually [8,9].…”

“…Currently, new dam designs are evaluated considering the management of sediment loads, minimizing their impact on the environment, and respecting the transit of fish, which are under ecological standards being implemented [8]. The capacity of dams around the world is decreasing by about 1% annually [8,9]. All these considerations related to sediment handling directly impact the turbine.…”