Standards for Ecologically Successful River Restoration Palmer et

Standards for Ecologically Successful River Restoration Palmer et al. , 2005, Standards for Ecologically Successful River Restoration Dylan Castle

Overview • • 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 – – – 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 • • • 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 q. 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 q 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. q 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 • • 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 – – – • 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