Transcript Strategic, Watershed Scale 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
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 sciencebased, watershed scale approaches to stream
restoration and mitigation.
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.
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.
Relevant Spatial Scales
8 digit
12 digit
Site Scale
Segment Scale
10 digit
Relevant Spatial Scales
SCALE
ACTIONS
6-8 HUC
Watershed Master Plan “Families”; Restoration goal to maximize
fishery recovery at this scale (“Region”)
(Cheat – Mon River)
10-12 HUC
(Muddy Creek –
Lower Cheat River)
Reach
(Lower Muddy Creek)
Site Location
(Mine portal)
Key scale of planning and coarsest scale of prioritization;
Watershed Restoration Master Plans (“Neighborhood”)
Scale of predictive modeling and Eco-currency calculation;
finer scale prioritization (“House”)
Scale of remediation action and finest scale of decision making
(“Plumbing”)
Stream Data
•Water Chemistry
•Temperature
•Instream Habitat
•Biological communities
•Ecosystem processes
Landscape Data
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
Watershed Model
•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.
Monitoring & Assessment
• Assess progress towards implementing
the master plan
Project Implementation
Watershed Restoration
Master Plan
•
•
•
•
5 year plan
Priority implementation sequence
Expected costs and fisheries benefits
General guidance regarding reclamation
project designs
• Construction of priority reclamation
projects
Stakeholder Input
Reclamation Design
• Detailed engineering design of priority
reclamation projects
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.
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.
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)
Cost of various restoration
alternatives
Benefit in terms of
coldwater fishery EU
recovery
Cost : Benefit Ratios
over time
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.
“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)
Reach Scale Restoration Priorities and
Restoration Package C:B Analysis
Reach ID
Basin
Area
(km2)
Stream
Length
(m)
Restorable
CWEUs
(m)
36194
49.9
3524
1054
35207
29.6
2645
782
38987
36.9
3209
616
39925
27.0
2153
580
33486
33.9
1680
569
36029
22.7
1916
434
30763
13.0
3446
430
43882
25.7
1547
398
39387
29.8
1263
376
44296
16.5
2284
376
41891
21.0
1742
366
RP1
Cost
RP2
1,000,000 500,000
Benefit 1452
1010
C:B
495
689
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
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.
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.
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.
The Mitigation Problem
Mitigation = replacement of lost ecosystem structure
and function resulting from development impacts.
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.
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).
Towards an Integrated
Mitigation Policy
I. Integrate Wetland and Stream Mitigation
On-Site to Maximize On-Site Recovery of
Aquatic Ecosystem Functions.
II. Integrate On- and Off-site Mitigation to
Maximize Watershed Scale Benefits and
Meet Total Impact Liability.
Research Needs
• What ecosystem functions are being lost during
mine development?
• What functions are being recovered through onsite 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?
Application to Mine Development
• Step 1: Estimate EU losses resulting from
proposed development
– Functional EU based on organic matter
processing
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.
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.
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.”
Hypothetical Example
• Projected Impacts from Mining
– Jurisdictional wetlands:
– Jurisdictional streams:
– Headwater Function EUs:
2 acres
3 miles
9 EUs (2%)
• On-Site Mitigation Plan
– Direct Wetland Offset:
– EU Offset via Wetlands:
– EU Offset via Streams:
2 acres
6 EUs (4 acres)
1 EUs (1 mile)
• Off-Site Mitigation Plan
– Remaining stream liability: 6 EUs (2 miles)
Hypothetical Example
• Pre-Mining Conditions On-Site
– Jurisdictional wetlands:
– Jurisdictional streams:
– Headwater Function EUs:
2 acres
3 miles
9 EUs (2%)
• Post-Mining Conditions On-Site
– Wetlands:
– Stream Channels:
– Headwater Function EUs:
6 acres
1 mile
7 EUs
• Post-Mining Conditions Off-Site
– Restored HW EUs:
– Restored stream channel:
6 EUs
2 miles
Hypothetical Example
• Net Change at Watershed Scale
–
–
–
–
Wetland Area:
Stream Channel:
Improved Stream Channel
Headwater Function EUs:
+ 4 acres (200%)
- 2 miles (33%)
+ 2 miles
+ 4 EUs (150%)
Mine Development
Plan
•Projected impacts
•Stream miles
•Headwater EcoUnits
On-Site Mitigation
Plan
• Linked wetland – stream
channel complexes
• Maximize HW function offset
Watershed Restoration
Master Plan
• 8 – 10 digit HUC scale
• ID dominant stressors
• Maximize ecological recovery at
the watershed scale
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
Mitigation Policy based on
Ecological Function…
• provides a way to:
– Integrate wetland and stream construction to meet onsite 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
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