Gunnison and Green River Basin Sediment Monitoring and Evaluation Program

Science Center Objects

Underlying geomorphic processes relevant to the formation and maintenance of backwater habitats are relatively poorly understood, particularly the effects of peak-flow magnitude and duration; sediment deposition and erosion; base-flow magnitude and variability; and antecedent conditions on habitat availability and conditions. Knowledge of sediment dynamics in important river reaches is critical to understanding the effects of flow regimes on endangered fish habitats.

The goal of the sediment monitoring program is to provide information with which to evaluate changes in the magnitude, timing, and size distribution of sediment delivery to the Gunnison and Green River systems resulting from water-resource development and land use changes in the basin, and their potential effects on the riverine ecosystem, specifically as they relate to recovery of the endangered fishes.


  1. Determine the availability of historic sediment data for the key sites on the Colorado, Gunnison, and Green Rivers near Green River, Utah. This objective includes an evaluation of the data to determine their utility for developing sediment-transport equations, evaluating trends in sediment transport, and evaluating how variations (wet and dry years) in annual hydrographs affect sediment transport.
  2. Support the evaluation of the effects of the flows and sediment movement on the morphometric and bed-material characteristics of Gunnison and Green Rivers.
  3. Determine if there is any distinction between sediment load estimates computed from daily sediment data, sediment transport equations, and empirical bedload transport equations.
  4. Evaluate the dynamics of sediment movement in the study reaches by collecting and analyzing data to compute sediment load, including suspended-sediment loads computed using daily samples and loads estimated using sediment transport equations. Water-surface slope and bed-material samples will be collected at two sites to support bedload calculations using published sediment-transport equations.