1. Ecological Systems Maintaining and Enhancing Natural Features and Minimizing Adverse Impacts of Infrastructure Projects Module 6 Restoring Ecological Function

2. Emily Mitchell Ayers, Ph.D.
The Low Impact Development Center, Inc.

3. Learning Outcomes Understand the value of ecological restoration
Learn to focus on restoring ecological function rather than appearance
Become familiar with techniques employed in a variety of restoration contexts

4. Ecologically-Sensitive Design Process
Know where you are
Avoid sensitive areas
Minimize infrastructure impacts
Mitigate unavoidable losses
Improve ecological function where possible

5. Mitigation Banking
When damage to a wetland, stream, or aquatic resource is unavoidable, impacts may be offset by restoring or preserving an equivalent resource off-site
Mitigation Banks are areas set aside to create large-scale, intact ecosystems
EPA

6. Advantages of Mitigation Banking
Wetlands in mitigation banks are restored prior to the destruction of existing wetlands on-site, which allows verification of equivalent function
Larger intact ecosystems are more stable than smaller, fragmented systems, and can support larger wildlife

7. Caveats
Mitigation banking is well-established only for wetlands; other ecosystems, especially upland ecosystems are not included
Some small wetlands, such as vernal pools, are critically important for amphibian breeding and migratory birds

8. Ecologically-Sensitive Design Process
Know where you are
Avoid sensitive areas
Minimize infrastructure impacts
Mitigate unavoidable losses
Improve ecological function where possible

9. Basic Principles of Ecological Restoration
Consult with experts
Remove barriers to ecological function
Establish key species to jump-start self- organization
Provide connectivity to existing habitat
Be patient!

10. Consult with Experts
Ecological restoration is a discipline in its own right
A growing number of specialists around the country have expertise and experience with restoration projects
Including experts on your team can help to ensure success and avoid unintended consequences

11. Remove Barriers to Ecological Function
Energetic barriers
Altered hydrology
Material barriers
Excessive nutrient inputs
Altered sediment deposition (too much or too little)
Contamination
Species-specific barriers
Noise, light pollution, habitat requirements, connectivity

12. Install Key Species
Usually, this involves establishing an appropriate plant community
The plant community provides a backbone for the ecosystem, allowing colonization by animals

13. Provide Connectivity to Existing Habitat
This promotes colonization by species adapted to site conditions as they disperse from adjacent habitats

14. Using Succession and Self-Organization
It is impossible to physically reconstruct a functioning ecosystem, as you would build a car
Creating appropriate conditions, and providing as much biodiversity as possible will allow the ecosystem to self-organize

15. Patience
Some ecological processes take place over very long time periods (e.g. topsoil development, peat bog formation)
It may or may not be possible to hurry these processes along to meet human timetables
Once energy and material flows are restored, ecological processes will take over, and will eventually establish a functioning, complex, ecosystem

16. If you build it, they will come
(provided they can get there)

17. Restoring Hydrology in Streams
Stream geomorphology (the size and shape of the stream bed and banks) is a direct response to the size of storm flows

18. Morphology of a Stable Stream
NEH 653

19. Morphological Changes Due to Urbanization
Disconnection from floodplain
Northern Virginia Soil and Water Conservation District

20. Incised Stream
Northern Virginia Soil and Water Conservation District

21. Match Morphology to Hydrology
If in-stream structure and meanders are rebuilt without addressing underlying hydrologic issues, there is a strong likelihood that restoration efforts will fail
Restored stream morphology must match the current energy signature

22. Options to Restore Hydrology
BEST OPTION: restore watershed hydrology, then rebuild in-stream physical features Unfortunately, watershed hydrology is the cumulative result of actions on multiple sites, so this is not generally possible in the context of a single infrastructure project

23. Restoring Stream Hydrology
ALTERNATE STRATEGY:
If possible, use floodplain to detain and infiltrate stormwater runoff
Install energy dissipating structures to reduce erosive power of storm flows

24. Energy Dissipating Structures
Rock weirs
Prevent scouring
Dissipate energy
Direct flows away from banks
Northern Virginia Soil and Water Conservation District

25. Bank Stabilization
Where flow velocities permit, banks can be stabilized with vegetation
Biodegradable reinforcements can be used while vegetation becomes established
In highly erosive conditions, stone may be necessary

26. Restoring In-stream Habitat
Tree trunks with root wads can be used to slow and direct flows and provide habitat
Trunks must be firmly anchored in stabilized banks
BLM

27. Reducing Nutrient Inputs
OPTIONS:
Reduce fertilizer application in watershed
Capture and treat runoff close to the source
Capture and treat runoff at the point where it is discharged to the water body (end-of- pipe)

28. Removing Nutrients Close to the Source
Wastewater Treatment: Tertiary treatment to remove nitrogen and phosphorus
Agriculture: Use vegetated buffers between fields and surface waters
Stormwater: Remove nutrients using Low Impact Development BMPs such as bioretention

29. End-of-pipe Options Regenerative stormwater conveyance (RSC)
Constructed wetlands
DDOE
EPA

30. Reducing Sedimentation
Install erosion control structures, either in-stream or within watershed
Live fascines
and coir blanket
FWS

31. Restoring Wetland Hydrology
Wetland hydrology is all about flooding depth and frequency
These two parameters must be correct for a wetland restoration project to be successful
FWS

32. The Importance of Wetland Hydrology
Wetland plants are primarily responsible for maintaining wetland structure and function
These plants have very specific hydrologic requirements
NRCS

33. Restoring Sedimentation
Remove dams and levees where possible
Install energy dissipating structures to reduce erosion and promote settling
Install sediment diversion structures
Trucking in sediment is a short-term fix, but may fail in the long run if erosive forces and subsidence are not balanced by ongoing deposition

34. Sediment Diversion
USACE

35. Lake and Pond Restoration
Lake and pond deterioration is usually a result of excess nutrient loading
In addition to methods previously discussed, nutrients can be removed using
Algal turf scrubbers, and
Floating islands.

36. Algal Turf Scrubber™ (ATS)
Water is pumped down a chute seeded with filamentous algae
Algae grows, taking up excess nutrients
Algae is harvested periodically, preventing eutrophication related to die-off
University of Maryland – NEED PERMISSION

37. Floating Islands Floating treatment wetlands
Wetland plants are suspended on floating mats
Remove excess nutrients from the water column
Floating Islands International
NEED PERMISSION

38. NW3.4 Maintain Wetland and Surface Water Functions
3 points: Enhance one ecosystem function
6 points: Enhance two ecosystem functions
9 points: Enhance three ecosystem functions
15 points: Enhance four ecosystem functions
19 points: Restore full ecosystem function

39. NW3.4 Maintain Wetland and Surface Water Functions (cont’d)
Enhance hydrologic connections
Reconnect rivers to their floodplains
Restore wetland hydrology
Enhance water quality
Disconnect surface water discharges
Use BMPs to infiltrate runoff
Enhance habitat
Restore riffles, pools, shoreline
Plant appropriate species
Enhance sediment transport
Remove dams and other impediments

40. Restoring Disturbed Lands
Areas connected to intact habitat will tend to regenerate following disturbance
Natural successional processes may take decades
Invasive and exotic species may need to be controlled

41. Fire-Dependent Ecosystems
Controlled burns can help to restore fire- dependent ecosystems
Manual removal of underbrush may be an acceptable substitute where burning is infeasible, but some functions of fire are difficult to replicate
Some seeds require high temperatures in order to trigger germination

42. Soil Restoration
Soils are an essential component of terrestrial ecosystems
Soil restoration involves:
Removal of contaminants
Reversing soil compaction
Increasing soil organic matter
Restoring soil ecological function

43. NW3.3 Restore Disturbed Soils
8 points: Restore all soils disturbed during construction in the site’s vegetated area
10 points: Restore all soils disturbed as a result of previous development

44. NW3.3 Restore Disturbed Soils (cont’d)
Prior to development, topsoil should be removed and stockpiled
After development, topsoil is replaced on unpaved disturbed areas, and quickly vegetated to minimize erosion
Restoring soils disturbed as a result of previous development may require amending and aerating soils

45. Repairing Contamination
OPTIONS:
Capping
Physical removal (dredging, soil removal)
Bioremediation
Phytoremediation

46. Bioremediation Use of bacteria to break down or transform contaminants
Involves creation of environmental conditions conducive to bacterial function
May require bioaugmentation with specialized bacteria or catalysts
Lawrence Berkeley National Laboratory

47. Phytoremediation Use of plants to bind or break down contaminants
Hyperaccumulators translocate metals from soil into plant tissues, which can be harvested
Hybrid poplars detoxify organic solvents
NIH

48. Reducing Light Pollution
Limit nighttime lighting to only what is necessary for safety
Use lights that cast light downward rather than upward
NPS

49. Reducing Noise Pollution
Plant trees to dampen noise
Construct noise barriers around highways
FHWA

50. Discussion Questions
What issues might you encounter if you attempted to restore an abandoned farm to its predevelopment condition?

51. Discussion Questions
How is it possible to restore streams, lakes, and wetlands if you have no control over what is happening in the watershed?

52. Review Mitigate unavoidable ecosystem losses
Restore ecological function wherever possible
Consult with experts
Remove barriers to ecological function
Establish key species to jump-start self-organization
Provide connectivity to existing habitat
Be patient!

53. Recommended Resources
Society of Wetland Scientists. SWS Position Paper: Wetland Mitigation Banking.
Society for Ecological Restoration, SER Primer on Ecological Restoration.
NRCS Stream Restoration Portal.
NRCS, Engineering Field Handbook, Chapter 18: Soil Bioengineering for Upland Slope Protection and Erosion Reduction ftp://ftp-nhq.sc.egov.usda.gov/NHQ/pub/outgoing/jbernard/CED- Directives/efh/EFH-Ch18.pdf
USEPA. Principles for the Ecological Restoration of Aquatic Resources.