Sediment Transport and Resulting Deposition in Spawning Gravels, North Coastal California

Incubating salmonid eggs in streambeds are often threatened by deposition of fine sediment within the gravel. To relate sedimentation of spawning gravel beds to sediment transport, infiltration of fine sediment (<2 mm in diameter) into clean gravel beds, bed material size distributions, scour-fill depths, and sediment transport during 10 storm flow events were measured in three streams of north coastal California. Although suspended sediment comprised most (75–94%) of the clastic load during storm flows, bed load material (0.25–2 mm) accounted for most (70–78%) of the fine sediment accumulated in experimental gravel implanted in the streambeds. Sand trapped in the interstices of the top several centimeters formed a seal that impeded deeper deposition of very fine sand and finer material. The seal was responsible at least in part for a decrease in the rate of fine-sediment accumulation with increasing cumulative bed load transport. Areas of the streambeds commonly scoured or filled 0.1 m or more during storm flows, and thus scour and fill commonly created a sandy layer at least as thick as the seal formed by sediment infiltration. Scour could erode eggs laid in the bed and expose deeper levels of the bed to infiltration by fine sediment, but at the same time could allow fine sediment to be winnowed away. Great temporal and spatial variation in sedimentation in these streams suggests that individual storms of moderate size pose a threat to eggs in many but not all areas selected by fish for spawning.

[1]  W. Megahan,et al.  Time trends in riverbed sediment composition in salmon and steelhead spawning areas: South Fork Salmon River, Idaho. , 1975 .

[2]  E. Andrews.  Entrainment of gravel from naturally sorted riverbed material , 1983 .

[3]  T. Lisle.  A sorting mechanism for a riffle-pool sequence: Summary , 1979 .

[4]  H. Ikeda,et al.  Pulsations in Bedload Transport Rates Induced by a Longitudinal Sediment Sorting: A Flume Study using Sand and Gravel Mixtures , 1987 .

[5]  Robert B. Thomas.  Estimating Total Suspended Sediment Yield With Probability Sampling , 1985 .

[6]  R. Beschta,et al.  A model of two-phase bedload transport in an oregon coast range stream , 1982 .

[7]  Robert L. Beschta,et al.  The Intrusion of Fine Sediments into a Stable Gravel Bed , 1979 .

[8]  P. Carling,et al.  Structure, composition and bulk properties of upland stream gravels , 1982 .

[9]  P. Klingeman,et al.  On why gravel bed streams are paved , 1982 .

[10]  W. Emmett.  A field calibration of the sediment-trapping characteristics of the Helley-Smith bed-load sampler , 1980 .

[11]  R. Beschta,et al.  Gravel Bed Composition in Oregon Coastal Streams1 , 1980 .

[12]  J. C. Briggs,et al.  The Behavior and Reproduction of Salmonid Fishes in a Small Coastal Stream Permalink , 2022 .

[13]  W. Dietrich,et al.  Bed Load Transport in a River Meander , 1984 .

[14]  P. J. Whiting,et al.  Bedload sheets in heterogeneous sediment , 1988 .

[15]  P. Carling.  Deposition of Fine and Coarse Sand in an Open-Work Gravel Bed , 1984 .

[16]  James W. Burns.  SPAWNING BED SEDIMENTATION STUDIES IN NORTHERN CALIFORNIA STREAMS 1 , 1970 .

[17]  R. Ziemer.  Storm flow response to road building and partial cutting in small streams of northern California , 1981 .

[18]  R. Palmquist.  Preferred position model and subsurface symmetry of valleys , 1975 .

[19]  H. Stefan,et al.  BEDLOAD TRANSPORT IN A MODEL GRAVEL STREAM. , 1980 .

[20]  P. Diplas,et al.  Pollution of Gravel spawning grounds due to fine sediment , 1985 .

[21]  Ramaswamy Sakthivadivel,et al.  Clogging of Porous Column of Spheres by Sediment , 1970 .

[22]  Hans A. Einstein,et al.  Deposition of Suspended Particles in a Gravel Bed , 1968 .

[23]  I. Reid,et al.  The incidence and nature of bedload transport during flood flows in coarse‐grained alluvial channels , 1985 .

[24]  H. P. Guy,et al.  Laboratory theory and methods for sediment analysis , 1969 .

[25]  G. Parker.  Self-formed straight rivers with equilibrium banks and mobile bed. Part 1. The sand-silt river , 1978, Journal of Fluid Mechanics.

[26]  R. Sidle,et al.  BEDLOAD TRANSPORT IN A POOL‐RIFFLE SEQUENCE OF A COASTAL ALASKA STREAM1 , 1985 .

[27]  T. Lisle.  A Sorting Mechanism for a Riffle-Pool Sequence , 1979 .

[28]  Ian Reid,et al.  The infiltration of fine matrices into coarse-grained alluvial sediments and its implications for stratigraphical interpretation , 1984, Journal of the Geological Society.

[29]  T. Lisle.  Stabilization of a gravel channel by large streamside obstructions and bedrock bends , 1986 .

[30]  R. Bagnold.  The nature of saltation and of ‘bed-load’ transport in water , 1973, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[31]  T. M. Smith,et al.  Sampling Techniques, Second Edition. , 1964 .

[32]  R. Kuhnle,et al.  Bed load transport fluctuations in a gravel bed laboratory channel , 1988 .

[33]  Peter R. Wilcock,et al.  Methods for Estimating the Critical Shear Stress of Individual Fractions in Mixed-Size Sediment , 1988 .

[34]  R. M. Rice,et al.  A watershed's response to logging and roads: South Fork of Caspar Creek, California, 1967-1976 , 1979 .

[35]  R. Williams,et al.  Effects of sedimentation on the gravels of an industrial river system , 1980 .