Post Construction Report
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INTRODUCTION
This report summarizes the construction completed on the Fox Creek Restoration Project through May, 2004. With the exception of two tasks (the placement of two pre-vegetated sod mats (to be installed on July 22, 2004) and the completion of an educational sign scheduled for August 2004, the Friends of the Teton River (FTR) and Huntsman demonstration project is completed at this writing. The project was accomplished in two major phases. The first phase involved the instream channel bedform manipulation work in November 2003 on the upstream half of the project (from station 12+00 to 26+00). Using the natural gravel supply in the creek, the bed was manipulated with a tracked excavator to create new channel geometry and pool-run-riffle sequences in an otherwise mostly plane-bed channel. This work is documented in the “Fox Creek Construction Report: Subreach 2 Instream Habitat Creation” dated December 1, 2003, by Gillilan Associates, Inc. (GAI). The second phase included the remaining instream bed manipulation work (from Station 0+00 to Station 12+00) and all the bank work and riparian revegetation efforts all the entire length of the project (from Station 0+00 to Station 26+00). The original contract limited bank and revegetation efforts to the downstream 1,500 feet (from Station 0+00 to 15+00). However, once work began, the landowners hired GAI to extend the bank work and riparian revegetation efforts to the entire project, adding 1,100 feet of additional bank work to the project (station 15+00 to 26+00).
SUMMARY OF WORK ACCOMPLISHED
Gillilan Associates, Inc. completed phase two of the Fox Creek project in May 2004. The project had two major components: (1) instream bed manipulation and (2) bank stabilization and riparian revegetation. The work accomplished in these areas is discussed in detail below.
Instream bed manipulation
We feel the work performed resulted in dramatic and positive changes to in-channel fish habitat and believe that the designed changes in channel geometry will result in self-maintaining habitat. The work reduced channel top-widths from up to 50 feet wide to an average of about 20 feet, (with variation in top widths being an integral part of the natural channel design) added pools with average depths between 4-6 feet deep, runs 3-4 feet deep, and well-oxygenated riffles in pool and run tail-outs for spawning, and created numerous shallow backwater areas designed for juvenile rearing habitat. Narrower top widths were achieved by narrowing channel sections with lateral and point bars created with gravel excavated from pools and runs. The heights of the bars were designed to be inundated during runoff and function as “floodplains” with “normal” spring flow.
Created gravel bars and banks used three techniques, each demonstrating different methods and creating the opportunity to compare the performance, cost and benefit of the different treatments. Between stations 15+00 and 26+00 the original design called for leaving the bars as bare gravel bars. Over time these are bars are projected to accumulate sediment and recruit sedges and juncus species to form new vegetated channel margins. A slight modification of this method was the second technique which used the same bar forms but then planted them with “bucket plugs” of sedge material. The sedges were dug from nearby donor areas and removed on 9-sq ft centers. Plugs were planted on the bars on 2-ft centers. As this was not within the scope of the project, and complete coverage on all bare bars was not achieved. The Huntsman family expressed interest in making this an on-going family project.
Photo 1. Station 26+00, sedge “bucket plugs” of hand–spaded carex transplants on 1-foot centers on a newly created gravel bar.
In contrast to the bare or plug planted gravel bars upstream of Station 15+00, the third demonstrated technique of channel narrowing occurred downstream of Station 15+00 where all but two gravel bars were subsequently revegetated with donor wetland sod and soil mats harvested from over-irrigated hay meadows expressing wetland plant attributes. Species in the harvested sites include young willow root suckers, fowl bluegrass, tufted hairgrass, Baltic rush, slender sedge, beaked sedge, Nebraska sedge, common rush and bluejoint reedgrass. Harvested sites were back-filled and leveled with soil excavated from bank pull-backs and re-seeded with pasture grasses.
Photo 2. Created gravel bar downstream of Station 5+00 covered with donor wetland sod harvested on the property
As a final demonstration, two gravel bars below Station 15+00 (Photo 3) will be covered with pre-vegetated wetland sod mats on July 22, 2004. Species in the mats are to include beaked sedge, water sedge, creeping spikerush, small fruited bulrush, and hardstem bulrush.
Photo 3. Gravel bar prepared for pre-vegetated sod mat at Station 3+50.
Several “sod barbs” were also created as designed per previous designs report (Photo 4). These serve a dual purpose of reducing active channel top width, while also creating functional backwater habitat for juvenile trout.
Photo 4. Showing example of a sod barb and juvenile trout backwater rearing habitat upstream of Station 14+00
Riparian Revegetation
The contracted project scope involved intensive revegetation of banks on the downstream half of the project (Stations 0+00 to 15+00). Although bank treatments had been designed for the entire project length, the contract called for only the downstream portion to be treated due to cost considerations. Once into the full swing of the project, the Huntsmans decided it would be worthwhile to extend the willow revegetation efforts throughout the entire project reach while labor and expertise were available. The Huntsmans also requested that additional bank work be done while heavy equipment was on site. The Huntsmans covered the additional costs associated with these changes.
Willows
GAI worked closely with Chris Hoag of the NRCS Plant Materials Center in the design and implementation of the revegetation effort. Over 3,000 willow poles (trimmed of all branches and leaves) were collected and planted into the banks using a waterjet stinger provided by the NRCS (Photos 5 and 6). Species of willows planted included sandbar, yellow, Booth, Bebb and Geyer.
Photos 9 and 10. Collection and installation of dormant willow poles
An additional 1,625 untrimmed willow poles of the same varieties were collected for a vertical bundle treatment (Photo 7). This involved laying bundles of willows vertically along banks, and covering the lower two-thirds with soil. A number of different means for installing these vertical bundles was utilized. Initially willows were tied into bundles of 4 to 6 and placed in trenches that were either hand-dug or dug with a mini-excavator. This process was lengthy and involved a lot of hand labor. Subsequently the large excavator was used to key in a trench at the bottom of the slope. Willows were laid separately along the trench, then the trench was back-filled with soil by the excavator. This significantly reduced the time it took to install the vertical bundles.
Photo 7. Vertical willow bundles along re-contoured bank. Willow sprouting success as of this report is near 95%.
Twenty-five mature willow plants were transplanted from on site to the banks of Fox Creek (Photo 8). The 15 to 20-tall willows were buried approximately 6 feet below ground in wet soil, then backfilled. The clumps were then trimmed.
Transplanted willow clumps near Station 2+00
Trees
A total of 67 containerized trees were planted for this project. The original scope called for 37 trees. The Huntsmans added an additional 30 trees in choosing to extend the revegetation effort to the entire length of the project. Species planted included 4 narrowleaf cottonwood, 17 aspen, 5 birch, 12 yellow willow, 20 Bebbs willow, 3 alder, 3 hawthorn, and 3 chokecherry trees. The maps included in Appendix A show the locations of these plantings. All trees were staked for stability and caged to protect them from beavers (Photos 9 and 10)
Photos 9 and 10. Planting trees with mini excavator and caged trees along bank near station 9+00
Photos 11 and 12.Before and after the bank at Station 8+00. The banks on this site were re-sloped, planted with aspen, willow clumps and willow poles. The channel was dramatically narrowed with gravel bars and then planted with donor wetland sod.
The bank between stations 1+50 and 3+00 was especially ragged prior to restoration. Because it is an outside bend that receives some erosive force, and because a ranch road runs close to the edge of the bank along this bend, additional effort was undertaken to address it. The overhanging bank was scalped and a revetment of Christmas trees was installed along the bank at or below water level. Sod was placed on top of the revetment for added protection.
Photos 13 and 14 showing installation of pine tree revetment, placement of transplanted sod on top of the revetment to create an erosion resistant bank toe.
The left bank at station 1+00 demonstrated the technique of stacking sod against the vertical, bare bank rather than re-sloping the bank.
PERMITTING/WATER QUALITY
FTR collected water quality data during construction. Turbidity exceeded Idaho water quality standards by several hundred NTUs directly below where the excavator was working and then fell off downstream. Once initial readings indicated that the Idaho water quality standard for turbidity was being exceeded FTR and IDFG were able to quickly obtain a temporary variance for turbidity exceedance from the Idaho Department of Water Resources (IDWR). FTR has the turbidity data for the project.
MONITORING
Flow Measurements
GAI measured discharge in Fox Creek several times over the course of the last year. The results are summarized in Figure 1 below. Flow measurements were made near Station 12+00. On May 11, 2004 GAI installed a staff gage below the bridge, where at a flow of 21.6 cfs the gage read 1.70 feet. Additional flow measurements correlated to the staff gage will allow a stage-discharge curve to be constructed. This relationship, while still approximate, will allow gage readings to be correlated to discharge without making measurements.
Figure 1. Discharge measurements on Fox Creek taken by GAI
Heavy rains on June 10, 2004 caused the creek to rise about a half a foot to a reading of 2.3 feet on the gage according to Jay Hanson (Crary’s ranch manager). The flow stayed this high for about 48 hours. This level inundated most newly sodded banks with about 2-3 inches of water and in some areas created turbulent flows on outside bends. A discussion of how the work performed in this runoff event is discussed in the “Project Performance Observations to Date” section below.
Temperature
Two continuous temperature data loggers were placed on the property in September 2003. One was placed at the bridge, and the other near the downstream property boundary. Appendix B shows the range of temperatures from September 2003 through April 2004. Additional downloaded data will be provided to FTR when it is retrieved in late July.
Cross Sections
Ten monitoring cross-sections (Appendix C) demonstrate the dramatic physical changes made to channel geometry along almost the length of the project. These ten cross sections are monumented with metal stakes on the left and right banks. Long-term monitoring will document how the pools runs and riffles perform over time in maintaining their form.
Photos
Before and after photos also document the changes (Appendix D). Seven permanent photo points were monumented with metal stakes on the banks for long term monitoring. They are marked with red asterisks in the photos in Appendix D. Locations of the photo points are shown on the attached maps. Upstream and downstream photographs were taken at each photo point.
This report concludes GAI’s reporting on the project. However, FTR and others will be continuing with long term monitoring efforts.
PERFORMANCE OBSERVATIONS TO DATE
Instream Habitat
The work experienced a significant but short-lived runoff event weeks after construction. Casual observation of channel geometry post-runoff shows little if any deviation from the as-built condition with the exception of obvious fine sediment deposition on constructed bars. Observation also suggests that most pools and runs are inhabited by trout. YCT were observed spawning in several locations in the treated areas this past spring by FTR.
Revegetation
At least 95% of the planted willow poles and stems in willow bundles are sprouting as of this writing. New leader growth on stems is approaching 6 inches. The donor sod mats performed extremely well resisting erosive runoff forces despite the fact that they hadn’t time to knit the mat roots to the underlying gravel before runoff. Some of the willow clumps are showing signs of stress and will be monitored.
ACKNOWLEDGMENTS
The Fox Creek Restoration Project was a joint effort by individuals to numerous to name, agencies, consultants, non-profit organizations and volunteers. Funding for the project was provided by the Huntsman Family and Friends of the Teton River through an EPA grant. Idaho Fish and Game (with help from FTR) obtained and held the necessary permits for the restoration work. Gary Vecellio (IDFG) worked tirelessly to obtain the permits and worked with all parties to resolve issues as they arose and earned our sincere respect and admiration as a project facilitator/fixer. Friends of the Teton River, notably Lyn Benjamin, the wonderful staff, and board members (thanks for the tree duty Tom Fenger, the bank looks great) conceived, coordinated and contracted the project, and provided an excellent volunteer force. Many many heartfelt thanks to the hard working volunteers wrangled by FTR who worked through very nasty weather without complaint and with an abundance of good humor and spirit. The U.S. Army Corps of Engineers brought peer reviewers to the project design in the form of Chris Hoag of the NRCS Plant Materials Center and Hollis Allen and ultimately permitted the project. Chris Hoag worked closely with Cindy Hoschouer of Land and Water, Inc. to design and oversee the riparian revegetation effort. Chris’s open mind, depth of knowledge and willingness to participate at all levels added a great deal to the project. Terry Blau of the Idaho Water Resources office made two special trips to monitor the work on the project and was invaluable in getting the project permitted under trying circumstances. Ditto for the Idaho DEQ who allowed us to proceed with necessary turbidity variances. The Crary family kindly allowed us access to the property to perform the work and has been very tolerant of the equipment and disruption to their property over the last year. Thanks also to the heavy iron artistry of Kelly Rowe of Rowe Excavation who always makes us look good. The Huntsman Family and friends provided the lion-share of the volunteer and “paid slave” work crew in an impressive show of family support, hard work and unity (especially Beach, who saw it all). Particularly, we thank Blaine and Nancy Huntsman, our tireless advocates and clients and friends of the YCT. (Thanks for the trust). Their energy, drive and support made this project a reality. And to all friends of Fox Creek, those named above and those inadvertently not mentioned (but not unappreciated) thanks so much for the opportunity to work on this special project. Long live Fox Creek and the YCT!
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