1. Regional/National Sediment Yields: Application of Fundamental Fluvial Geomorphic Techniques for TMDLs National Sedimentation Laboratory Andrew Simon USDA-ARS National Sedimentation Laboratory

2. Impairment to Designated Uses by “Clean Sediment” Suspended Sediment High concentrations over specified durations Potentially lethal/sub-lethal to organisms Bed-material High rates of bed-material transport over specified durations (unstable bed) Loss of habitat for benthic macro-inverterbrates Deposition of fines Ditto How does “clean” sediment impair waterbodies?? National Sedimentation Laboratory

3. Some Definitions Shear stress: Force applied by flowing water on the surface of the stream bed (function of flow depth and slope) Transport Capacity: Maximum amount of sand-sized and larger sediment a stream can carry at a given discharge or shear stress Sediment Availability/Supply: Amount of sediment supplied from all upstream sources Sediment Load: Mass or volume of sediment transported per unit of time Sediment Yield: Mass or volume of sediment transported per unit of time and drainage area. National Sedimentation Laboratory

4. Fundamental Mechanism QS  Q s d 50 Q = water discharge S = bed or energy slope Q s = bed-material discharge d 50 = median particle size of bed material Streams are open systems with an ability to adjust National Sedimentation Laboratory

5. A Rapid Means of Evaluating Thousands of Streams is Needed National Sedimentation Laboratory We don’t have the time or the money to perform detailed analyses at every site that needs to be evaluated and that may require a TMDL Still, a scientifically defensible procedure is required The very popular Rosgen Classification offers one such means of rapidly classifying streams easy to understand novices can perform excellent communication tool about channel form

6. Process, Process, Process National Sedimentation Laboratory Use Form to Tell Us About Process Channel Evolution Models Use Form to Infer Process Schumm et al., 1984 Simon and the Hupp, 1986; Simon, 1989

7. Stages of Channel Evolution (just another empirical model) National Sedimentation Laboratory References Stage I Stage VI

8. Stage and Fish-Community Structure

9. Clean Sediment TMDLs: Geomorphic Link Develop methodology to evaluate “reference” and disturbed conditions Disturbed channels transport greater volumes of sediment for a given discharge Rates of bed material and suspended-sediment transport vary by stage of channel evolution

10. Level III Ecoregions and Available Data National Sedimentation Laboratory

11. Field Work Locations (as of April 2010) National Sedimentation Laboratory

12. Effective and Bankfull Discharge  Effective discharge is that discharge or range of discharges that transports the largest portion of the annual sediment load over the long term (Leopold and Wolman, 1960; Wolman and Miller, 1960; Andrews, 1980).  Generally accepted to be the bankfull discharge.  Annual-maximum series (1.5 years) or Partial- duration series (1.0 years)??  Simon et al., 2004 verified this for numerous ecoregions National Sedimentation Laboratory

13. Definition Sketch of Effective Discharge National Sedimentation Laboratory

14. Two-Stage Suspended-Sediment Ratings 26,000 T/D 110,000 T/D

15. National Sedimentation Laboratory Three-Stage Suspended-Sediment Ratings 4,900 T/D 12,000 T/D

16. Nationwide Median Q 1.5 Concentrations National Sedimentation Laboratory

17. Nationwide Median Q 1.5 Yields National Sedimentation Laboratory Highest in continental United States AZ/NM Plateau

18. National Sedimentation Laboratory Q 1.5 Sediment Yields: Hawaii

19. National Sedimentation Laboratory Median Suspended-Sediment Concentrations

20. National Sedimentation Laboratory Median Suspended-Sediment Yields

21. EPA Region VIII

22. Suspended-Sediment Transport

23. An Example: Ecoregion 17

24. Stages of Channel Evolution (to identify processes) National Sedimentation Laboratory References Stage I Stage VI

25. “Reference” Yields

26. Mean Annual Yields

27. Mean-Annual Reference

28. Refined “Reference” by Bed- Material Size Class Ecoregion 65

29. Comparing Reference to Actual Yields How much reduction is required?

30. National Sedimentation Laboratory Preliminary Reference Yields

31. Frequency of Given Concentrations What are thresholds for aquatic health? National Sedimentation Laboratory

32. Durations of Given Concentrations What are thresholds for aquatic health? National Sedimentation Laboratory

33. Duration of High Concentrations and Benthic Populations National Sedimentation Laboratory

34. Frequency of Bed-Material Movement National Sedimentation Laboratory More unstable site (degraded)

35. National Sedimentation Laboratory Frequency and Duration Metrics Frequency Duration

36. Metrics for Stable and Unstable Sites FrequencyDuration

37. “Reference” Frequency of Exceedance (%) National Sedimentation Laboratory Highly erodable and disturbed loess area Lowland coastal areas Plains Mtns.

38. “Reference” Frequency of Exceedance (Days) National Sedimentation Laboratory Highly erodable and disturbed loess area Lowland coastal areas

39. “Reference” Durations National Sedimentation Laboratory Highly erodible and disturbed loess area Lowland coastal areas

40. Developing a “Reference” Bed-Material Composition for the Ridge and Valley and Shades Creek A reference bed-material composition is based on a measure of embeddedness; The percentage of materials finer than 2 mm (sand, silt and clay) in gravel or gravel/cobble-dominated streambeds; Applies to 53 of the sites evaluated along Shades Creek and 34 sites in the Ridge and Valley.

41. Developing a “Reference” Bed-Material Composition Ridge and ValleyShades Creek Median for both the Ridge and Valley and Shades is 4% Consider the 75 th percentile

42. Comparison of Embeddedness Values for the Ridge and Valley and Shades Creek

43. Application to San Juan River Basin

44. Stage of Channel Evolution

45. Ecoregion 22 Bed-Material Reference Inter-quartile range: 0 – 20% National Sedimentation Laboratory

46. San Juan River Basin Reference Inter-quartile range: 12 – 30% National Sedimentation Laboratory

47. Animas River National Sedimentation Laboratory

48. Bed-Material Conditions for Study Reaches National Sedimentation Laboratory