Potential sedimentation impacts related to dam removal : Icicle Creek, Washington, U.S.A.
Aménagement hydraulique ; Barrage ; Cours d'eau ; Ecosystème aquatique ; Etats-Unis ; Pisciculture ; Qualité de l'eau ; Sédimentation ; Washington State
Aquatic ecosystem ; Dam ; Fish breeding ; Hydraulic works ; Sedimentation ; Stream ; United States of America ; Washington State ; Water quality
A series of small dams were built in Icicle Creek in 1937. A flow-competence approach was used to assess the restoration potential of the river to do the work of flushing sediments and reestablishing the predam stream channel characteristics
. A sediment probe, a total station, a GPS and aerial photographs were used to map out sediment deposits and measure their depths to determine sediment volumes. Grain size distributions from bed sediments, bars, islands and stream banks were used to assess
potential downstream sedimentation impacts. The total volume of sediment trapped behind the dams was estimated. Control flushing of the trapped sediments over several years poses very little threat to water quality and spawning habitats.
Dam ; Dammed lake ; Earth surface processes ; Hydraulic works ; Romania ; Sediment budget ; Sedimentation ; Silting ; Watershed
and considering the substantial accumulations of new data. The factual material that they have is structured as follows : the construction of dams and the arrangement of reservoirs in Romania; the problem of sediment sources and, the silting of reservoirs.
The role of impoundments in the sediment budget of the conterminous United States
Cultivated land ; Dam ; Hydraulic works ; Pond ; Reservoir ; Sediment budget ; Soil erosion ; United States of America ; Watershed
The AA. use the term impoundments to refer to artificial water bodies regardless of size (reservoirs and ponds). They examine the role of these small impoundments in the sediment budget, at the sub-continental scale. Specifically, they estimate
the total volume of sedimentation occurring in small impoundments and compare that quantity to other components of the fluvial sediment budget for the conterminous U.S. It is clear that most sedimentation is now taking place in subaqueous rather than
subaerial environments, and that small impoundments are a major sediment sink.
Sediment from hydraulic mining detained by Englebright and small dams in the Yuba basin
of mercury in sediment and fish tissues in the watershed are briefly reviewed. Third, historic data on 20th century hydraulic mining are presented that document numerous small dams built in the Yuba basin to detain mining sediment. Finally, field measurements
of the texture and lithology of modern bed materials in the Yuba River basin are presented that demonstrate reworked sediment from mining is an important component of the modern sediment load and fine spawning gravels.
Equilibrium or indeterminate ? Where sediment budgets fail : sediment mass balance and adjustment of channel form, Green River downstream from Flaming Gorge Dam, Utah and Colorado
Channel geometry ; Colorado ; Dam ; Floodplain ; Hydraulic works ; Meander ; Sediment budget ; Stream ; United States of America ; Utah
, and field observations. The AA. show that the sediment budget is indeterminate and that this river segment is not degrading, but is, in fact, accumulating sediment. They also show that robust measures of channel change over long reaches better characterize
the style and magnitude of channel adjustment than limited measures over short reaches. This analysis presents a new perspective on the relationship between sediment mass balance, channel-form adjustment, and reach-scale geomorphic organization.
Channel geometry ; Dam ; Hydraulic works ; New Mexico ; Regression analysis ; Sediment transport ; Statistics ; Stream ; United States of America ; Water regime
The Rio Grande downstream from Cochiti Dam exhibits spatial and temporal variability in lateral movement rates documented since 1918. A tremendous database exists that documents planform, bed material size, channel geometry, and water and sediment
that most strongly influences present geomorphological investigations connected with dams is related to habitat for endangered species, because the biological aspects of ecosystems are directly dependent on the substrate formed by the sediments and landforms