Controls on Sediment Transport and Storage in the Little Snake, Yampa, and Green Rivers in the Vicinities of Dinosaur National Monument and Ouray National Wildlife Refuge, Colorado and Utah, with Implications for Fish Habitat in the Middle Green River
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- Document: Report (15.2 MB pdf) , XML
- Related Works:
- Journal article - Long-term evolution of sand transport through a river network—Relative influences of a dam versus natural changes in grain size from sand waves
- Open-File Report 2023-1070 - Resurvey of cross sections on the Yampa and Little Snake Rivers in Lily and Deerlodge Parks, Colorado
- Scientific Investigations Report 2025-5078 - Channel and floodplain cross-section and bed-elevation analyses of the Green River in Echo, Island, and Rainbow Parks, Dinosaur National Monument, Colorado and Utah
- Data Release: USGS data release - Surveyed coordinates and elevations in a 2020 resurvey of previously established cross sections on the Green River between Jensen and Ouray, Utah
- Download citation as: RIS | Dublin Core
Abstract
The transport of sand and finer sediment in the Yampa and Green river network is typically in disequilibrium with the local sediment supply because of the partial decoupling of the sources of water and sediment: most of the water is supplied farther upstream than most of the sediment. This decoupling leads to sand being transported in the main-stem rivers as elongating sand waves following sand resupply during tributary floods. Because of the large amount of sand supplied to the Yampa River by the Little Snake River, Yampa River annual floods generate sand waves that migrate downstream in the Green River causing longitudinal patterns in bed-sand grain size that, in turn, lead to large spatial changes in sand transport. These changes in bed-sand grain size dominate over changes in water discharge in regulating sand transport in the sand-bedded reaches of these rivers. Furthermore, at any given discharge, these changes in bed-sand grain size dominate over all other processes in regulating sand transport in both sand- and gravel-bedded reaches of these rivers. Consequently, erosion or deposition of sand, and the associated changes in fish habitat in the Uinta Basin segment of the Green River are only indirectly related to Green River discharge and Flaming Gorge Dam operations. Owing to the longitudinal patterns of bed-sand grain size associated with the downstream migration of sand waves generated by the Yampa River, a multi-year sequence of large, and likely slightly declining, annual floods on the Yampa River is the probable mechanism that increases backwater fish habitat in the Uinta Basin segment of the Green River.
Cross-section resurveys indicate that the Uinta Basin (Jensen to Ouray) segment of the Green River has undergone sand erosion caused by slight channel widening since the 1990s (a channel response in opposition to that observed farther downstream in Canyonlands National Park during this period). These resurveys indicate that sand deposition leads to a decrease in channel complexity whereas sand erosion generally leads to an increase in channel complexity. The backwaters used as native fish nursery habitat consist of deep pools downstream from and adjacent to large bank-attached sandbars; thus, more extensive backwater habitat equates to greater channel complexity. The generation of the sand wave during the first large Yampa River flood in a sequence (that is, the year-1 flood) causes fining of the bed sand near Jensen. The downstream coarsening associated with bed sand that is finer near Jensen than downstream near Ouray causes a downstream decrease in sand transport in the Uinta Basin segment, leading to net sand deposition and decreased channel complexity. Continued downstream migration of this sand wave during the following year’s annual flood (that is, the year-2 flood) then causes downstream fining, leading to erosion of sand and increased channel complexity in this segment.
Although the year-1 Yampa River flood supplies the sand and deposits the large sandbars required to form backwaters, and thereby makes possible future backwater habitat, these floods cause a temporary reduction in backwater habitat in the Uinta Basin segment because they tend to cause net sand deposition. It is the subsequent out-year Yampa River floods of likely equal or lesser magnitude that maintain or increase backwater habitat because these are the floods that convey sand through or erode sand from this segment. These typically smaller out-year Yampa River floods rework the sandbars deposited during the year-1 annual flood, thereby leading to the increases in both backwater area and volume that have been measured upon recession of these floods. Although artificial floods released from Flaming Gorge Dam might be used to simulate the habitat maintenance achieved by out-year Yampa River floods, the limited sand supply and stage associated with such dam releases precludes their use as a replacement for the sandbar-depositing role of year-1 Yampa River floods that is a prerequisite for backwater formation in the Uinta Basin segment of the Green River.
Suggested Citation
Topping, D.J., Griffiths, R.E., Unema, J.A., and Dean, D.J., 2025, Controls on sediment transport and storage in the Little Snake, Yampa, and Green Rivers in the vicinities of Dinosaur National Monument and Ouray National Wildlife Refuge, Colorado and Utah, with implications for fish habitat in the middle Green River: U.S. Geological Survey Scientific Investigations Report 2025–5075, 117 p., https://doi.org/10.3133/sir20255075.
ISSN: 2328-0328 (online)
Study Area
Table of Contents
- Acknowledgments
- Abstract
- Introduction
- Study Area
- Purpose and Scope
- Importance of Tributary-Generated Sand Waves in the Study Area
- Field Methods
- Analytical Methods
- Results with Discussion
- Conclusions
- References Cited
- Appendix 1. Sediment Loads at Six U.S. Geological Survey Gaging Stations in the Vicinities of Dinosaur National Monument and Ouray National Wildlife Refuge
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Controls on sediment transport and storage in the Little Snake, Yampa, and Green Rivers in the vicinities of Dinosaur National Monument and Ouray National Wildlife Refuge, Colorado and Utah, with implications for fish habitat in the middle Green River |
| Series title | Scientific Investigations Report |
| Series number | 2025-5075 |
| DOI | 10.3133/sir20255075 |
| Publication Date | September 29, 2025 |
| Year Published | 2025 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Southwest Biological Science Center |
| Description | Report: xiii, 117 p.; Data Release |
| Country | United States |
| State | Colorado, Utah |
| Other Geospatial | Green River, Little Snake River, Yampa River |
| Online Only (Y/N) | Y |