Riparian Restoration in a Time of Changing Hydrographs: La Jencia 2008-2014
Beginning in the 1880’s, widespread gullying deeply incised streams throughout the West. Therefore, riparian restoration work has often focused on ways to stabilize rapidly eroding waterways. Where channel engineering is not cost-effective, native species plantings are promoted to inhibit erosion and jump-start channel aggradation. But the combined impacts of a changing climate and continuing vegetation disturbance mean that some streams will continue to evolve toward ever-changing equilibria of stream power and sediment load. Without a stable bank-full or predictable hydrograph to inform restoration efforts, engineered solutions and native riparian species plantings may catastrophically fail. However, even in highly impacted riparian areas, strategically located native species plantings can create resilient wildlife habitat. This talk examines a long-term riparian restoration effort on La Jencia Creek using repeat photography and aerial imagery. La Jencia is located at 5,000 feet in the uplands west of Socorro, NM. Current vegetation in the 288 square mile watershed consists of a mix of intact grassland and degraded shrubland. Landscape-scale watershed alteration and degradation extend far beyond the project boundary, so current floods occur more frequently, are ‘flashier’, and of higher volume than in the past. La Jencia creek has incised approximately 100 feet into fine sediments during the 20th century and rapid erosion and channel migration continue. In the wake of several ‘100-year floods’ in the last 15 years, over-meander cutoffs have significantly shortened and steepened the channel and initiated further channel incision. Restoration work began in 2006, when WildEarth Guardians, a nonprofit environmental advocacy and restoration organization, removed cattle and began invasive species removal. Native, locally-sourced riparian trees and shrubs were subsequently planted along a 2 mile project reach by volunteers and staff. While return to a pre-incision hydrograph or geomorphology may not be possible in a changing landscape, large improvements in riparian habitat are still within reach. This talk will demonstrate how native species planting techniques can succeed even in the context of continuing rapid channel evolution.
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Riparian Restoration in a Time of Changing Hydrographs: La Jencia 2008-2014
- 1. Riparian Restoration In a Time of Changing Hydrographs: La Jencia Creek, NM Conor R. Flynn, Bryan Bird, Jim Matison
- 4. Overview • Watershed Degradation • The 2006 Flood • Restoration Work 2008-2009 • The 2009 Flood • Conclusions
- 9. Watershed Degradation • Drought • Overgrazing • Desertification • Compacted Soil • Reduced Infiltration • Increased Runoff = Active Channel Evolution
- 10. A Finely Balanced Watershed
- 11. Geomorphology
- 12. 2006 Flood
- 13. Upper Reach - Before
- 14. Upper Reach - After
- 15. Upper Reach - Before
- 16. Upper Reach - After
- 17. Upper Reach - After
- 18. Upper Reach - 2008
- 19. Upper Reach - 2008
- 20. Riparian Restoration • Remove Cows • Remove Invasive Tamarisk • Plant Native Cottonwood and Willow
- 21. Thanks to Stream Team Volunteers!
- 22. Upper Reach – Before 2006
- 23. Detail of Planting Areas
- 24. Planting Areas – ‘Backbank’ Cottonwoods – In-stream and Bankside Willows and Cottonwoods
- 25. 2009 Flood • Sedimentation • Erosion
- 26. Upper Reach - 2008
- 27. Upper Reach – Summer 2008
- 28. Upper Reach - 2009
- 29. Deposition
- 30. Scour on Outside Meander
- 31. Lower Reach – Before 2009 Flood
- 32. Lower Reach – After 2009 Flood
- 33. Lower Reach – Before 2009 Flood
- 34. Lower Reach – After 2009 Flood
- 36. Lower Reach - 2008
- 37. Lower Reach – Summer 2008
- 38. Lower Reach - 2009
- 39. Lower Reach - 2009
- 40. Lower Reach - 2013
- 41. 2008
- 42. 2013
- 43. 2008
- 44. 2014
- 45. Conclusions • Bank-side plantings impacted by flood – Combination of cutting and deposition • Back-bench plantings thrive • Regrowth after disturbance • Can’t stop rapid channel evolution
- 47. 2008 – Before Restoration
- 48. 2013 – After Restoration, Flood, and Growth
- 49. Thank You • WildEarth Guardians and Jim Matison • Restoration Crew and Stream Team Volunteers • La Jencia Conservation Ranch • Funding from – NM Environment Department – USFWS – North American Wetland Act
- 51. 2013 2009 2013
- 52. 2009
- 53. 2013
- 54. Lower Reach - 2011
- 55. Lower Reach - 2011
- 56. Lower Reach 2013
Notes de l'éditeur
- La Jencia is a privately-owned conservation ranch, managed to provide and restore habitat for native wildlife, as an opportunity for outdoor education. Springs and cienegas feed over 4 miles of perennial stream in an otherwise ephemeral drainage.
- Another image of the ranch at the beginning of the restoration work. Multiple grants spanning many years, I’ll be talking about some of the initial riparian restoration work
- Watershed
- Watershed
- = Large disturbances and Rapid channel geomorphic response
- 4 factor model -- Hypothesizing that impacts are accumulating downstream. Alternately, upstream progression of nickpoints can explain downcuting…
- The 2006 Flood
- Cottonwoods, coyote willows, container plants. Volunteers
- 50,000 stems
- All in all planted 50,000 stems along 2 miles of river….
- 2008 Fall
- 2009 Fall
- 2009 Fall Erosion and Deposition
- 2013 Summer
- Large gooding willow line current chanel. Interesting to note that, before floods of 2006 the creek meandered along the edge of the cliff, right, where the excavators are auguring 12 foot holes for 16 foot cottonwood (Populus deltoides harvested from nearby Bosue Del Apache national wildlife refuge. There are sedges in the backwater / side channel wetland, bottom right.
- Note gooding willows still along main channel. Planted cottonwood are almost as big, filling in naturally at the base of the cliff. There were no cottonwood there in 2007-2008 planting, just some tamarisk that had to be removed. Why cottonwood didn’t occur there before is an interesting question – may have something to do with seeding and germinating timing and requirements of cottonwood, or over grazing, or… [am I sure these are the trees we planted?]
- 3 of 3 cienega
- 2 of 3 cienega
- 2 of 3 cienega - note this image is from higher up than 2009 image