This talk presents a habitat restoration project completed on the Stanislaus River, a tributary to the San Joaquin River. The primary objective of this project was to increase salmonid rearing habitat, and concurrent improvements to spawning habitat and the native plant community provided added benefit.

1. Honolulu Bar Floodplain Enhancement Project

2. Honolulu Bar Floodplain Enhancement Project: Background
• Stanislaus River spawning and rearing
habitat reduced by mining and dams
• Population constraints identified
through two decades of monitoring
• Honolulu Bar Restoration Project designed to
increase juvenile salmonid rearing habitat, among
other benefits
• Jointly funded by Oakdale Irrigation District and
the Anadromous Fish Restoration Program

3. Honolulu Bar Floodplain Enhancement Project: Location

4. Project Design: Key elements
Create rearing bench
Augment riffle
habitat
Re-connect
side channel
Create floodplain

5. Implementation: Re-connected side channel
• Problems
• Limited shallow water, low
velocity rearing habitat
• Stranding
• Project accomplishments
• Nearly one-half mile of re-connected
side channel habitat.
• Side channel remains connected
at all flows
Before
After

6. Implementation: Created small floodplain
• 1.51 acres of excavated floodplain
• Floodplain begins to inundate at ~400 cfs; fully inundated at ~1,000 cfs

7. Implementation: Created rearing benches
• Approximately one-quarter mile (0.28 acres)

8. Implementation: Augmented riffle habitat
• 3,325 yds3 of gravel added to the main channel
• Increased spawning habitat
• Increased rearing habitat

9. Implementation: Project scale
Stanislaus River
0 10 20 30 40 50 60
Yolo
Cosumnes
Stanislaus River
Honolulu Bar
Thousands of Acres
Honolulu Bar

10. Post-restoration monitoring: Salmonid response

11. Post-restoration monitoring: Adult salmon
• Bi-weekly redd surveys
• Entire spawning reach
• Pre: 2007-2011
• Post 2012 and 2013

12. Post-restoration monitoring: Adult salmon
100%
75%
50%
25%
0%
Riffle area 2012 2013
Unrestored
Restored
Proportion of Redds

13. Post-restoration monitoring: Juvenile O. mykiss rearing
Newly emerged steelhead
indicated spawning in the
improved side-channel
3000
2000
1000
0
0.03
0.02
0.01
0
1-Jan 31-Jan 2-Mar 1-Apr 1-May 31-May
O. mykiss Flow

14. 3,000
2,000
1,000
0
0.3
0.2
0.1
0
1-Jan 31-Jan 2-Mar 1-Apr 1-May 31-May
Flow (cfs)
Salmon / sq. ft.
Post-restoration monitoring: Juvenile salmon rearing
2013
2014
3,000
2,000
1,000
0
0.3
0.2
0.1
0
1-Jan 31-Jan 2-Mar 1-Apr 1-May 31-May
Flow (cfs)
Salmon / sq. ft.
Honolulu Bar Horseshoe Flow

15. Post-restoration monitoring: Juvenile salmon production

16. Post-restoration: Lessons Learned
• Juvenile salmon and steelhead used newly created habitats that were
not previously available
• Restored areas were used almost immediately
• Use of restored area by juvenile salmon was not significantly different
than unrestored area
• Use of restored areas by adult salmon is higher than unrestored areas
• Ongoing monitoring provides baseline and measures population level
response to habitat restoration and other actions intended to increase
salmon production
• Response to cumulative efforts to improve salmon abundance not yet
clear.

17. Questions?