Standards for Ecologically Successful
River Restoration
Palmer et al., 2005, Standards for Ecologically Successful River Restoration
Dylan Castle
Overview
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What is Successful Restoration
5 criteria for River Restoration Standards
Examples of Restoration
Conclusion
What is Successful Restoration?
• Main focus: Improving environmental conditions
• Ideally successful restoration
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Cost-effective
Outcome satisfying to shareholders
Aesthetically pleasing
Provided knowledge for future restorations
Ecologically successful
• Currently, no accepted set of restoration standards
– Most projects never monitored post-restoration
Five Criteria for Measuring Successful
Restoration Projects
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Guiding Image
Improved Ecosystem
Increased Resilience
Harmless
Availability of pre- and post- project
assessment
1. Guiding Image
• Establishment of ecological endpoint to guide
restoration
• There is no universal standard for all rivers
– Image needs to be realistic and site specific
– Considers biologic, hydrologic, and
geomorphologic aspects
E.g. Reconfiguring a braided channel to a
meandering channel may not fit geomorphology
Establishing an Image
• Aerial photographs, maps, ground photography, and land
records
 Example: U.S. Government land surveys from 1800’s were used as a
reference for contemporary restoration projects on the upper
Mississippi
• Using undisturbed or previously restored sites as reference.
– Taking into consideration geomorphology, hydrology, climate,
geology, and zoogeography.
 Example: Using steep, mountainous streams as a guide to restore
meandering valley rivers.
Establishing an Image Cont.
• Employing empirical models
– Knowledge of channel, sediment, and hydraulic
relationships to form design parameters.
– Useful if no reference conditions present
• Stream classifications
– Ordering into groups based on common
characteristics.
– Factors: channel pattern, gradient, bed material size,
and sediment load.
• Common sense
– Areas with no riparian vegetation may simple need
planting of new riparian vegetation.
2. Improved Ecosystems
• Ecological conditions of a river need to be
measurable enhanced
– Fish populations
– Improved water clarity and quality
– Seasonal meadows and floodplains
• Improvements take time
– Different ecological variables take different
amounts of time to recover.
– Variability can actually be a signal of successful
restoration as natural systems are themselves
variable
Improved Ecosystems Cont.
• Clear understanding of scale and severity of
constraints needs to be established.
• Level of Restoration depends on many factors
– Funding, infrastructure limits, and stakeholder
needs
• Restoration improvement limits lie at the
point where ecological and stakeholder
outcomes are met and future efforts benefit
from acquired knowledge.
3. Increased Resilience
• River ecosystem is more self-sustaining then
before restoration
• Successful restorations have characteristics that
can recover from rapid changes and stresses
– Being able to recover from floods
• Without restoring resilience:
– Need ongoing repair
– Constant management
Increased Resilience Cont.
• Hard engineering structures should be
avoided
• Some situations may require hard engineering
– Facilities that prevent incision but encourage
lateral movement
– Establishing culverts or pathways for access to fish
spawning areas
4. Harmless
• Implementing restoration does not permanently
harm the system
– Minimize loss of native vegetation
– Construction during non-spawning seasons
– Not removing an riparian vegetation
• Restoration does not inflict harm somewhere else
– Example: Restoration efforts that lead to permanent
increases in downstream sedimentation
5. Assessment
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Assesses pre- and post- restoration information
Established positive and negative affects
Information is readily available for other projects.
Some projects are easily assessable
– Checking to make sure replanted riparian vegetation is
still alive
– Water quality/temperature has improved
Restoration Example 1
• Problem: Increase of peak runoff in urban
areas due to runoff of impervious surfaces
• Solution 1: Creating floodplain wetlands to
intercept runoff and increase infiltration
• Solution 2: Construct rock walls or rip-rap.
Solution 1 is better. Uses abilities to moderate
flow. Also does not need long-term maintenance
or repair. Therefore, more self-sustaining.
Example 2
• Problem: Channel disconnected from floodplain
in large lowland rivers
• Solution 1: Levee breaching or widening.
• Solution 2: Periodic Dredging
Solution 1 restores a natural periodic process
benefits propagation of native species and natural
flood retention. Solution 2 is costly and significantly
disrupts ecology. Also requires regular
maintenance.
Conclusion
• Ideally successful restoration
–
–
–
–
–
Cost-effective
Outcome satisfiable to shareholders
Aesthetically pleasing
Provided knowledge for future restorations
Ecologically successful
• 5 Criteria for Measuring Restoration Success
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–
–
–
–
•
Guiding Image
Improved Ecosystem
Increased Resilience
Harmless
Availability of pre- and post- project assessment
Two Perspective for Ecological Goals
– Moving away from a degraded state
– Approach a desired improved condition