Canyon Creek Complex
Canyon Creek Suite of Rehabilitation Sites:
Trinity River Mile 73 to 78: Objectives & Activities
The Canyon Creek Suite of Channel Rehabilitation Sites (Project) implemented a host of channel and riparian rehabilitation measures to provide needed juvenile fish habitat and to restore historical river form and function on the mainstem Trinity River downstream of Canyon Creek. The Project is located on a reach of the Trinity River, beginning approximately 1 mile (at RM 78) below Junction City, a small community in Trinity County, California and continuing in a downstream direction to RM 73, about a mile upstream of the confluence of the North Fork and mainstem Trinity Rivers. The project reach includes four separate rehabilitation areas; Conner Creek, Valdor Gulch, Elkhorn , and Pear Tree Gulch. (Pictures from Conner Creek and Valdor Gulch are highlighted on the home page and channel rehabilitation design maps for these sites — in pdf format, are available at the bottom of the page, under the Project site area map). The Project was constructed during October and November 2006 and revegetation occured in late 2006.
This channel rehabilitation effort selectively removed fossilized riparian berms (berms that are anchored by extensive woody vegetation and consolidated sand deposits) and reconnected the river's floodplain with the river at intermediate flows (between 500 and 6,000 cubic feet per second (cfs) depending on site specific characteristics). Removal of these riparian berms and selected vegetated areas, which had developed after construction of upstream dams eliminated scour associated with peak flows, is expected to promote healthy river processes necessary for the restoration and maintenance of Trinity River salmonid rearing habitats. The Project also utilized Large Woody Debris (LWD) extensively on its excavated floodplains and within constructed fish habitat areas (e.g., low-water alcoves and side channels). This LWD will provide immediate fish habitat when inundated and will increase habitat complexity as high flows re-work the as-built conditions.
The recently completed construction of this Project provides immediate fisheries habitat, but more importantly, allows the river access to the floodplain where it will:
- increase the diversity and area of habitat for salmonids, particularly habitat suitable for rearing;
- increase rearing habitat for juvenile salmonids, including coho, chinook, and steelhead;
- increase the structural and biological complexity of habitat for various species of wildlife associated with riparian habitats;
- increase hydraulic and fluvial geomorphic diversity and complexity; and
- measure/demonstrate the ecological response to changes in flow regimes, morphological features, and aquatic, riparian, and upland habitats.
In addition to berm and vegetation removal, the TRRP defined additional treatment activities for implementation in the Canyon Creek Project which targeted enhancement of river processes and creation of juvenile fish rearing habitat. A summary of these activities, at each Canyon Creek rehabilitation area, is included in the table below.
Downstream of Canyon Creek River Rehabilitation Activities*
| Hocker Flat |
Conner Creek | Valdor Gulch | Elkhorn | Pear Tree Gulch | |
| Riverbank Activities: | |||||
| 1. Clearing and grubbing only |  |
|
|
|
|
| 2. Berm removal only | |
||||
| 3. Feathered edge (10:1 slope) | |
|
|
|
|
| 4. Alcove/backwater | |
|
|
|
|
| Floodplain Activities: | |||||
| Constructed Floodplain: | |||||
| 5. Low flow bench | |
||||
| 6. 2,000 cfs bench | |
||||
| 7. 1.5 year flow bench | |
|
|
|
|
| 8. High flow scour channel | |
|
|||
| 9. Side channel | |
||||
| 10. Revegetation | |
|
|
||
| Upland Activities: | |||||
| 11. Materials stockpiling and spoiling | |
|
|
|
|
* Monitoring: Will be required in all areas to determine program success or failure and to plan future projects to incorporate new information.
Elkhorn (mouse over for photos)
 R5 terrace, July 6, 2006pre-project |
R4 floodplain, October 20, 2006 - during construction |
R5 area, December 13, 2006, post construction |
 |
||
Pear Tree Gulch - large woody debris
Valdor Gulch (mouse over for photos)
| Valdor Gulch pre-construction, April 4, 2005 |
Valdor Gulch during construction, October 11, 2006 |
Valdor Gulch after construction, December 8, 2006 |
 |
||
| Map of Valdor Gulch project [PDF - 500kb] | ||
Conner Creek (mouse over for photos)
| Conner Creek pre-construction, July 6, 2006 |
Conner Creek during construction, Nov. 9, 2006 |
Conner Creek after construction, Dec. 7, 2006 |
Revegetation at Constructed Floodplain, Nov. 14, 2007 |
 |
|||
 |
Map - Elkhorn [PDF - 1mb]
Map - Pear Tree Gulch [PDF - 1.1mb]
Map - Valdor Gulch [PDF - 1.3mb]
Map - Conner Creek [PDF - 850kb]
