Stream Mitigation and Ecological Function in Mined Watersheds

1. Stream Mitigation and Ecological Function in Mined Watersheds Todd Petty, PhD Division of Forestry and Natural Resources March 31, 2009

2. Acknowledgments Jennifer Fulton Gretchen Gingerich Eric Merriam Megan Minter Jenny Newland (CVI) Mariya Schilz Paul Ziemkiewicz OSM USGS USEPA Magnum Consol Argus

3. The MTM Debate Extensive alteration of headwater catchments from surface mines Best available technologies are used to mitigate for necessary environmental impacts. Reclamation effectiveness in recovering lost headwater functions is unclear.

4. Headwater Functions • Water Retention and Flood control • Aquifer recharge • Soil retention • Organic Matter retention and processing • Nutrient retention and cycling • Support of vertebrate and invertebrate communities • Transport of dilute freshwater and processed detritus, nutrients, and biomass to downstream systems

5. Pre-mining Function – Post-mining Function = Mitigation Requirement - =

6. - = • What functions are being lost from the native catchments? • To what extent, if any, are reclaimed areas functioning as headwater catchments? • What are the remaining functional deficits? • Can deficits be met on-site through improved reclamation? • Can remaining deficits be met and justified through off-site restoration actions?

7. Functional Value of Reclaimed HWs 5 Reclaimed HWs 5 Paired Native HWs • Compare and contrast functions • Identify opportunities for improvement

8. Newly Reclaimed Perimeter Complex (2 yrs)

9. Established Perimeter Complex (20 yrs)

10. Typical Perimeter Outflow

11. Structural and Functional Measures of Aquatic Ecosystems Perimeter Channels Reference Channels -Canopy* -Gradient* -Amphibian Assemblage* -Invertebrate Assemblage* -Sediment Composition* -Habitat Quality* -Vegetation* -Canopy* -Gradient* -Amphibian Assemblage* -Invertebrate Assemblage* -Sediment Composition* -Habitat Quality* -Vegetation* -Water Chemistry* -OM Retention* -OM Decomposition* -Nutrient Uptake -Biotic Productivity and Diversity* -Dissolved Carbon* -Discharge*

12. Structural Differences

13. Water ChemistryAverage Seasonal Measurements

14. Mined Reference Mined Reference Amphibians

15. Mined Reference Mined Reference Macroinvertebrates

16. OM Retention Artificial Sticks P. Channel Reference

17. OM Decomposition P. Channel Reference

18. OM Processing Power* *Highly Preliminary!!! • 100 g of detritus enters into a 100 m channel segment on day 0 • Processing Power = total amt decomposed within the 100 m segment over some period of time (400 days). • Over a period of 400 days: • 64 g of OM are processed within the reference channel • 54 g of OM are processed within the reclaimed channel • Leaves a “functional deficit” of 10 g OM processing power per 100 m per 400 days

19. Dissolved Carbon • WHOK is a young mine – all C is inorganic (bicarbonate) • DOC tends to increase with mine age (except for BIHO?) • DOC lower in reference streams, but dominates TC (no bicarbonate) • Dissolve carbon paints a good picture of ecosystem processes. • OM “stewing” in mined channels. • OM “chewed up and spit out” of reference channels. P. Channel Reference P. Channel Reference

20. Reclaimed HWs Take Home • Reclaimed HWs are fully transformed and differ markedly from native catchments with regard to structure, vegetation, and sediments. • Reclaimed catchments support altered, but productive, invertebrate and vertebrate communities. • The OM processing functions of reclaimed HWs are altered but largely retained – there is a measurable functional deficit that may be addressed through off-site mitigation. • High TDS and elevated conductivity of outflows from reclaimed catchments may be the most important difference between reclaimed and native HWs.

21. Improvements to Reclamation? • Focus on maximizing the wetland functions of reclaimed catchments vs. rebuilding lotic structures • Plant diversity, bird habitat, nutrient and OM processing, water and sediment storage • Functional losses related to OM processing may be best addressed through off-site mitigation • Increasing OM retentiveness in small perennial streams nearby • TDS problem is a big issue, and HW catchment protection may be necessary to maintain clean, freshwater sources in mined watersheds. • Connections to downstream systems remain unknown.

22. Newly Reclaimed Perimeter Complex (2 yrs)

23. Low Retentiveness High Retentiveness OM Retention = fn (drainage area, gradient, structural complexity)

24. Pigeon Creek: Tools Needed to ID Off-Site Mitigation Opportunities and Put Into a Currency Transferable to the Impacted HW Catchments • 30 Sites • Drainage Area • Gradient • Habitat Quality • Channel Complexity • OM Retention • OM Decomp

25. Relationship Between OM Retention and Stream Channel Complexity Makes it possible to predict the “functional lift” of a stream restoration project

26. Pre-mining Function - Post-mining Function = Mitigation Requirement - =

27. Calculation of Recoverable OM EcoUnits Associated with Stream Restoration Projects

28. What is the Functional Value of a Mitigation Project? 1.24 km stream length 0.68 km OM Retention Units

29. Conclusions • Reclaimed HW catchments are functioning very well in some ways, and not so well in other ways. • OM processing Ecological Units can be used to make objective decisions about acceptable functional deficits from mining and functional lift from off-site mitigation. • We must begin to address the TDS issue in intensively mined watersheds, which will require integration of HW protection into the decision making process. • We have proposed a 4 Phase mitigation process, which can ensure the protection of HW catchment functions and maximize watershed scale ecological values.

30. A Watershed Scale Mitigation Process for WV Minelands

31. Fix It!