1. GIVEN GEOMORPHIC REGIME AND IMPACTS, WHAT IS REQUIRED?
Potential for geomorphic work
Degree of impact to natural physical process
GIVEN GEOMORPHIC REGIME AND IMPACTS, WHAT IS REQUIRED?
‘FUNCTIONAL DESIGN’
‘INITIAL CONDITIONS DESIGN’
ACTIVE RESTORATION
‘ASSISTED RECOVERY’
‘DO NOTHING’
HYTECH Symposium, Aug. 2016

2. Project Example (UK) – River Nairn at Aberarder
IFM ‘The Big Fish’, Oct. 2017

3. Project Example (UK) – River Nairn at Aberarder
20th September 2017
flow
IFM ‘The Big Fish’, Oct. 2017

4. Project Example (UK) – River Nairn at Aberarder
IFM ‘The Big Fish’, Oct. 2017

5. Project Example (UK) – River Nairn at Aberarder
9th Oct.
20th Sept.
20th Sept.
POT
TAIL
9th Oct.
flow
IFM ‘The Big Fish’, Oct. 2017

6. ECOLOGICAL BENEFITS OF WETLANDS
Refugia from high flows and cover from predators – access back to main channel important
Potentially important in controlling water temperatures
Maintaining river baseflows in the summer
Management/ storage of fine sediment
Rearing habitat? (high food supply/ low energy expenditure)
2. Potentially overwintering habitat?
IFM ‘The Big Fish’, Oct. 2017

7. Project Example (UK) – River Nairn at Aberarder
~28,200m2 of online wetland habitat created
flow
flow
Approximate extents of wetland/ pond areas areas.
IFM ‘The Big Fish’, Oct. 2017

8. Project Example (UK) – River Nairn at Aberarder
flow
IFM ‘The Big Fish’, Oct. 2017

9. Project Example (UK) – River Nairn at Aberarder
flow
IFM ‘The Big Fish’, Oct. 2017

10. Project Example (UK) – River Nairn at Aberarder
flow
Baseline data available for fish populations and post-implementation monitoring planned.
Monitoring underway – post-construction physical resurveys already begun and plan to be conducted periodically.
IFM ‘The Big Fish’, Oct. 2017

11. Allt Lorgy: Restoration Plan
Main tool: large wood and rootwad placements.
Removal of boulder armour
Removal of embankments
Gravel augmentation

12. Comparison of old and new channels (4 years apart)
Aerial image mosaic of post-restoration channel
Pre-restoration channel

13. Allt Lorgy 2D hydraulic model
Focus in on an area where the restoration (with large wood) has increased hydraulic complexity
Detailed topographic survey and 2D hydraulic models pre and post-restoration.
Redd surveys.

14. Project Example (UK) – Allt Lorgy
2012
2014
IFM ‘The Big Fish’, Oct. 2017

15. Project Example (UK) – Allt Lorgy
2011 (pre-design)
2014 MODELLED SPAWNING HABITAT
Pre-design to post-flood
REDDS
REDD
14 redds in 2016!
IFM ‘The Big Fish’, Oct. 2017

16. Acknowledgements
HYTECH Symposium, Aug. 2016