FY07-09 proposal 200705400

Jump to Reviews and Recommendations

Section 1. Administrative

Contacts

Section 2. Locations

Province / subbasin: Columbia Cascade / Entiat

Section 3. Focal species

Section 4. Past accomplishments

Section 5. Relationships to other projects

Section 6. Biological objectives

Section 7. Work elements (coming back to this)

Section 8. Budgets

Itemized estimated budget

Total estimated FY 2007-2009 budgets

Cost sharing

Section 9. Project future

Future O&M costs:

Termination date:
Comments:

Final deliverables:

Section 10. Narrative and other documents

Reviews and recommendations

ISRP PRELIMINARY REVIEW (Jun 2, 2006)

Recommendation: Response requested

NPCC comments: The ISRP believes the proposal has merit, but is requesting that the following concerns be addressed before a funding recommendation can be made. This project adopts an engineered approach to stabilizing the channel and streambank in the Stillwater area. If stronger evidence had been presented that bank erosion was having a detrimental impact on the channel at and below the project site, the proposal would have been more persuasive. Establishing the potential significance of the project would also require a more complete description of the sediment problems in the watershed. The significance of erosion at the project site cannot easily be judged without this context. The basic premise of this project is that the production of sediment from the eroding banks is impacting habitat quality and biological productivity at the project site. The only evidence provided is the level of fine sediment in the gravel. Bank erosion is attributed to past land-use practices and a lack of riparian vegetation, but it was not clear whether or not this area would erode regardless of past problems. The following questions were not addressed in the proposal, and the ISRP would like a response to them in addition to other concerns listed in the comments. Is erosion at this site an important source of gravel for downstream spawning areas? Are sediment sources upstream producing sufficient material to supply gravel and maintain channel form? A large portion of the budget will go toward placing approximately 125 rootwads and 240 cut logs in large woody debris (LWD) complexes to be spaced 10 feet apart. The reason for the 10-feet spacing is that it is believed to be necessary to prevent additional streambank erosion. There was no attempt to relate the proposed LWD additions to conditions in a similar, but relatively undamaged part of the Entiat or otherwise similar alluvial river valley. This regular spacing is not likely to occur naturally, and unless the LWD structures are very securely anchored, movement of the structures during high flow events is almost sure to happen. The objectives did not make clear whether either the structures or riparian plantings would be repaired after natural disturbances. The objectives tend to be generic, and in some cases the linkage between the project elements and the desired outcome is not clear. For example, the proposal indicates one of the biological outcomes is an increase in nutrient delivery to the channel as a result of riparian tree plantings. Although an increase in organic matter delivery to the stream with the re-growth of riparian trees and shrubs is likely, nutrient input may actually decline as a result of uptake by the new vegetation. Also, there is some confusion regarding the level of wood being added to the project reach. The background information provided at the beginning of the proposal indicates a desired level of large wood of about 20 pieces per mile of channel. However, this project plans to add a total of 365 pieces to about a half-mile of channel. We recognize increasing wood abundance is secondary in this project to bank armoring, but some indication of possible consequences of increasing wood levels to more that 15X the stated objective should be explored in the proposal. High flows are likely to alter the distribution of LWD structures and may affect the survival of some replanted riparian areas. Reducing sedimentation from the exposed streambank is a valid objective, but the solution could become costly to maintain if natural disturbance-mediated changes are not tolerated. Not enough detail is provided on the monitoring component of the project to evaluate it. However, the information that is provided raises some concerns. Many of the variables that are proposed are highly variable, both spatially and temporally (e.g., gravel fines, macroinvertebrates, and fish). The proposal implies that pre-treatment information on these parameters will be collected one time. There is very little possibility that a measurable response could be detected based on a single pre-treatment sample. Additional details should be provided to justify the work

ISRP FINAL REVIEW (Aug 31, 2006)

Recommendation: Not fundable

NPCC comments: The ISRP believes this proposal, while well intended, still has some serious deficiencies. The responses to the ISRP comments do not provide sufficient context to determine whether or not the project would address a significant problem in the Entiat watershed. The information on fine sediment in the gravels provides an indication that sediment levels are high at the site, but whether or not that sediment is being produced from the eroding banks at the project area is not clear. The McNeil core sample data are limited to the Stillwater reach, and there was little information on conditions elsewhere in the Entiat subbasin. Because sediment data are available for RM 0.5-34 since the early 1990s (a period that included several high intensity wildfires in the drainage), it would have been very helpful to have included a discussion of the role of fire in delivering sediment to the mainstem Entiat and what we know about how that sediment has been routed in the ensuing years. Without this spatial and temporal context it is difficult to ascribe the relatively high fines in the Stillwater reach to either bank erosion or fluvial delivery of other sediment from sources in the upper basin. The photographs certainly suggest bank erosion is a problem, but there was no way of determining its significance relative to other factors. Project sponsors suggest that the work is needed to reduce bank erosion from feet per year to inches per year. Supporting evidence is needed for this statement as well as for the comment that gravel recruitment from upstream sources is adequate. The statement that spawning gravel is recruited primarily from upstream and deposited at the study site also was not well substantiated. What is the composition of the eroding banks at the project site? Do they contain gravel? If they do and they are eroding rapidly, these banks may be an important source of gravel. Implementing the project without a better understanding of gravel recruitment would be risky. The response states that closely spaced (10 ft.) log structures along the streambank are needed to prevent scour pockets from forming. While scour pockets may be deemed undesirable from a sediment standpoint, it would have been useful to have included a discussion of its implications for fish habitat. If preventing bank erosion is the primary objective, why not just use rip-rap? The ISRP realizes rip-rap is almost always an undesirable solution and shouldn't be used in this instance, but the response could have been clearer if the LWD additions had been described in terms of their overall benefits to fish habitat (vis-à-vis sediment and rearing space). In that way, it would have been possible to explain why so many LWD pieces were being proposed, or if project sponsors were willing to reduce the quantities a bit to more closely emulate natural LWD loading. Additionally, given the width of the floodplain at this site (600 ft.), it is not unnatural for logjams to break up and re-form during high flow events. These natural disturbances are usually quite good for maintaining ecologically functional floodplains. It is understandable that the project would want to protect riparian tree plantings from floods for the first few years, but artificially anchoring LWD may have undesirable, and expensive, long-term consequences. Some provision for LWD movement may be worthwhile. The ISRP's comment about changes in nutrient input was not addressed. Nutrient input does not necessarily require overland flow. Dissolved nutrient input occurs through subsurface flow, and riparian root systems are likely to intercept some of the nutrients moving through the soil to the stream, at least during the growing season. The benefits associated with re-establishing vegetation along the channel are likely to outweigh any negative effects associated with nutrient interception. But the claim that the vegetation will increase nutrient delivery to the channel may not be true. The M&E section of the proposal remains weak. It is not clear that the ISEMP monitoring effort will measure parameters that are relevant to assessing the project's effectiveness. One of the primary objectives is the reduction of fine sediment in spawning gravel, but summer snorkel surveys provide only very indirect evidence that spawning conditions have changed. The gravel samples will provide some indication, although the connection between fine sediment concentrations in the gravel and sediment coming from the banks at the project site would need to be made to be certain that any reduction was related to the bank armoring. The most relevant biological measure would be an assessment of egg to fry survival, but there was no indication that this will be measured. If the monitoring effort is limited to implementation monitoring, as the response states, then the focus should be streambank and riparian vegetation. Instream performance measures will require a much more significant effort to detect real change. Hopefully, the ISEMP program will pick the instream metrics up, but this proposal should have concentrated on the streambanks and riparian zones and, especially, the success of revegetation efforts and the performance of the log structures. In summary, while the ISRP believes this site deserves protection, the proposal should have provided an improved context for the restoration proposal, more attention to simulating natural wood loading in the Entiat River floodplain, and a more focused M&E plan.