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Watershed Scale Approaches to Restoration and Mitigation

Watershed Scale Approaches to Restoration and Mitigation. Todd Petty and Paul Ziemkiewicz. Outline. Introduce the WTAC Watershed Scale Approach to Restoration Application to Acid Impacted Watersheds Breather Watershed Scale Approach to Mitigation Application to the MTM/VF Conflict.

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Watershed Scale Approaches to Restoration and Mitigation

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  1. Watershed Scale Approaches to Restoration and Mitigation Todd Petty and Paul Ziemkiewicz

  2. Outline • Introduce the WTAC • Watershed Scale Approach to Restoration • Application to Acid Impacted Watersheds • Breather • Watershed Scale Approach to Mitigation • Application to the MTM/VF Conflict

  3. WVWRI and WTAC • The goal of the Water Research Institute is to generate water research that supports State environmental policy initiatives. • WTAC complements efforts of the NMLRC • The goal of the Watershed Technical Assistance Center is to facilitate application of science-based, watershed scale approaches to stream restoration and mitigation.

  4. Ecological Restoration • Assisted recovery of ecological structure and function to ecosystems that have been degraded or destroyed. Ecological Mitigation • Replacement of lost ecosystem structure and function resulting from development activity.

  5. Watershed Restoration: Problems and Opportunities Extensive legacy impacts to rivers throughout the state. Problems are so extensive that all impacts cannot be fixed at once. Need to prioritize actions to meet watershed scale objectives (e.g., recovery of productive fisheries). Produce efficient, broad scale benefits to WV watersheds.

  6. Relevant Spatial Scales 8 digit 12 digit Site Scale Segment Scale 10 digit

  7. Relevant Spatial Scales

  8. StreamData • Water Chemistry • Temperature • Instream Habitat • Biological communities • Ecosystem processes • Fishery / Ecological Priorities • Priorities to maximize recovery of coldwater and warmwater fisheries (EcoUnits). • Reach scale and subwatershed (10-12 digit HUC) scale priorities. • Points to stream segments where recovered fisheries are possible, and if recovered, would be highly valuable. GIS-based WatershedModel • LandscapeData • Land Cover • Geology • Drainage Networks • Mine Data • Expected Development • Mine pool elevations • Reclamation Priorities • Action-by-action priorities needed to recover fisheries priorities. • Implementation of at-source, in situ, and instream reclamation actions. • Maximize cost:benefit efficiency. • Watershed Restoration Master Plan • 5 year plan • Priority implementation sequence • Expected costs and fisheries benefits • General guidance regarding reclamation project designs • Monitoring & Assessment • Assess progress towards implementing the master plan • Project Implementation • Construction of priority reclamation projects • Reclamation Design • Detailed engineering design of priority reclamation projects Stakeholder Input

  9. EcoUnit Concept = a measure of the functional significance of a measurable unit of stream (length or surface area). ***scalable from stream segment to whole watershed ***weighted based on “restorability” Examples: Coldwater Fishery EcoUnit = stream length (m) weighted by its value as habitat for brook trout spawning and juvenile recruitment (Petty and Thorne 2005). Warmwater Fishery EcoUnit = stream surface area (km2) weighted by its value as habitat for smallmouth bass (Merovich and Petty 2007). Organic Matter Processing EcoUnit = stream length (m) weighted by its value in converting coarse particulate organic matter to biomass. Biological Diversity EcoUnit = stream length (m) weighted by its value in supporting diverse aquatic communities.

  10. EcoUnits and Watershed Scale Planning • Petty, J. T., and D. Thorne. 2005. An ecologically based approach to identifying restoration priorities in an acid-impacted watershed. Restoration Ecology 13:348-357. • Developed a coldwater fishery EU to conduct a cost:benefit analysis of various limestone sand remediation alternatives in the upper Shavers Fork watershed. • Merovich, G. T., Jr., and J. T. Petty. 2007. Interactive effects of multiple stressors and restoration priorities in a mined Appalachian watershed. Hydrobiologia 575:13-31. • Developed an invertebrate diversity EU to assess the benefits of AMD treatment as an alternative offset to impacts from thermal effluent to the Cheat River mainstem. • Poplar-Jeffers, I. and J. T. Petty. 2007. Culvert replacement and stream restoration: application to brook trout management in an Appalachian watershed. Restoration Ecology (IN PRESS). • Applied the coldwater fishery EU to identify culvert replacement priorities and assess the benefits of culvert replacement as a form of mitigation for road related impacts to streams.

  11. EcoUnit Recovery Alternatives in the Upper Shavers Fork of the Cheat River WPRA = fn (expected brook trout spawning intensity given stream size, location, and gradient; expected juvenile survivorship given alkalinity and aluminum concentration) (in units of meters)

  12. Cost of various restoration alternatives Benefit in terms of coldwater fishery EU recovery Cost : Benefit Ratios over time

  13. EcoUnits and Use of Culvert Replacement as Mitigation • Watershed Scale Culvert Replacement Program for the Cheat River watershed • Strategy based on a brook trout ecological unit (WPRA). • Over 200 km WPRA isolated above 127 culverts. • Total cost of restoration = $6-8 Million. • Twenty culverts isolate 50% of WPRA at a cost of $500K to restore. • Objective mitigation currency.

  14. “Recoverable” CW and WW Fishery EcoUnits in the lower Cheat River. CWEU = fn (value as trout habitat given water temperature, habitat complexity, water quality, benthic invert diversity) WWEU = fn (value as smallmouth bass habitat given temperature, gradient, water quality and benthic invertebrate biomass) in units of km2 Restorability: likelihood of achieving conditions needed to support a fishery =fn (stream size, geology, mining intensity)

  15. Reach Scale Restoration Priorities and Restoration Package C:B Analysis

  16. Lower Cheat River Restoration and Monitoring Plan. Planning and Design Cost: $100,000 Implementation Cost: $2,800,000 Annual Maintenance Cost: $170,000 Expected EU Recovery: 185 km2 WW Fishery Cost / EU / year: $156 / EU / year (over 20 years) Annual Monitoring Cost: $30,000

  17. Benefits of Watershed Scale Perspective to Restoration • Framework for establishing measureable, human use related goals for restoration (recovered warm and coldwater fisheries). • Stream by stream restoration is ineffective (McClurg et al. 2007). • A little bit of planning at a watershed scale can produce broad-scale benefits with minimal costs. • Documenting watershed scale benefits is more efficient than monitoring the effectiveness of multiple projects.

  18. The Mitigation Problem Extensive alteration of headwater systems from surface mine development Best available technologies are used to mitigate for necessary environmental impacts. Mitigation effectiveness in recovering lost headwater functions is unclear.

  19. Headwaters = Ephemeral / Intermittent / Small Perennial Streams • Headwater Functions: • Water and sediment retention • Nutrient uptake and cycling • Organic matter retention, processing, and conversion to biomass • Habitat for invertebrate and vertebrate organisms • Supply of processed material to downstream ecosystems Headwaters are the “kidneys” AND the “digestive system” of the riverine ecosystem.

  20. The Mitigation Problem Mitigation = replacement of lost ecosystem structure and function resulting from development impacts.

  21. Important Issue #1: There is considerable “functional redundancy” between streams and wetlands. Opportunity to integrate stream and wetland restoration to recover the full suite of lost ecosystem functions on reclaimed surface mines.

  22. Important Issue #2: New mine development is occurring on top of legacy impacts. Acid Mine Drainage Untreated Sewage Opportunity to integrate on-site mitigation with strategic off-site mitigation to meet watershed scale goals (e.g., recovered fisheries).

  23. Towards an Integrated Mitigation Policy • Integrate Wetland and Stream Mitigation On-Site to Maximize On-Site Recovery of Aquatic Ecosystem Functions. • Integrate On- and Off-site Mitigation to Maximize Watershed Scale Benefits and Meet Total Impact Liability.

  24. Research Needs • What ecosystem functions are being lost during mine development? • What functions are being recovered through on-site mitigation of streams and wetlands? • Can we develop ecological currencies to compare functional values of reference headwaters, constructed wetlands, and constructed stream channels? • Are there ways to improve on-site mitigation so as to maximize recovery of functional losses? • Are there ways to integrate on- and off-site mitigation to maximize watershed scale benefits?

  25. Application to Mine Development • Step 1: Estimate EU losses resulting from proposed development • Functional EU based on organic matter processing

  26. Application to Mine Development • Step 2: Place projected EU losses into a watershed scale context • Quantify functional loss as a percentage of the total EUs “operating” in the watershed.

  27. Application to Mine Development • Step 3: Develop On-Site / In-Kind Mitigation Plan to maximize headwater EU recovery. • Construction of wetland, flowing channel, riparian corridor complexes. • Maximize sediment, water, OM, and nutrient retention. • Added local values: fishing, aesthetics, real estate value, bird habitat. • Valuation of On-Site EU credits. • Constraints: spoil permeability and isolation from downstream systems. • Typically end up with an EU deficit and a “structural” deficit.

  28. Application to Mine Development • Step 4: Obtain remaining liability through strategic Off-Site mitigation • Sequence of prioritized restoration actions in the watershed (stream bank stabilization, AMD remediation, habitat enhancement, riparian plantings, conservation easements). • Actions designed to meet measurable watershed scale ecological goals (e.g., productive fisheries, EU recovery). • Plans stipulate Mitigation Credit Value of Restoration actions. • Plans may be “pre-approved.”

  29. Hypothetical Example • Projected Impacts from Mining • Jurisdictional wetlands: 2 acres • Jurisdictional streams: 3 miles • Headwater Function EUs: 9 EUs (2%) • On-Site Mitigation Plan • Direct Wetland Offset: 2 acres • EU Offset via Wetlands: 6 EUs (4 acres) • EU Offset via Streams: 1 EUs (1 mile) • Off-Site Mitigation Plan • Remaining stream liability: 6 EUs (2 miles)

  30. Hypothetical Example • Pre-Mining Conditions On-Site • Jurisdictional wetlands: 2 acres • Jurisdictional streams: 3 miles • Headwater Function EUs: 9 EUs (2%) • Post-Mining Conditions On-Site • Wetlands: 6 acres • Stream Channels: 1 mile • Headwater Function EUs: 7 EUs • Post-Mining Conditions Off-Site • Restored HW EUs: 6 EUs • Restored stream channel: 2 miles

  31. Hypothetical Example • Net Change at Watershed Scale • Wetland Area: + 4 acres (200%) • Stream Channel: - 2 miles (33%) • Improved Stream Channel + 2 miles • Headwater Function EUs: + 4 EUs (150%)

  32. Mine Development Plan • Projected impacts • Stream miles • Headwater EcoUnits • Watershed Restoration Master Plan • 8 – 10 digit HUC scale • ID dominant stressors • Maximize ecological recovery at the watershed scale • On-Site Mitigation Plan • Linked wetland – stream channel complexes • Maximize HW function offset • Off-Site Mitigation Plan • EcoUnit based (HW and fishery) • Prioritized actions • Investment opportunities with associated credits • Seek pre-approval • Integrated Mitigation Plan • + HW Function • + Extent of Wetlands • + Functional Stream Miles • + Progress towards implemtnation of the WRMP

  33. Mitigation Policy based on Ecological Function… • provides a way to: • Integrate wetland and stream construction to meet on-site restoration objectives. • Integrate on- and off-site mitigation to meet watershed scale restoration objectives. • Quickly improve watershed conditions and the amount of functional streams and wetlands on the landscape • Defend the process as being rational, quantitative, and science based

  34. Benefits of Watershed Scale Perspective to Mitigation • Combines On-Site and Off-Site mitigation to meet watershed scale objectives. • Pre-approved watershed mitigation plans can reduce permitting time, cost, and uncertainty. • Science-based program that is legally defensible. • A platform for watershed-based mitigation banks. • Watershed plans that can be used by many: Industry, Division of Highways, County Planners, DEP, Watershed Organizations

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