This is a proposal to replace nine culverts on three tributaries in the Wenatchee River subbasin with pre-fabricated modular bridges. The problem of impassable or partially passable road crossings has long been known to be a problem, and there are a number of programs to correct them. According to the proposal, the three streams in question - Alder Creek, Clear Creek, and Beaver Creek - have been identified as high priority sites for barrier removal. However, documentation of species currently using these tributaries of the Middle Wenatchee and Chiwawa was not very complete, and the salmonid carrying capacity of the four miles (in total) of small streams that would be opened was not given. Other than to state that the culvert replacement projects would primarily benefit summer steelhead there was little quantitative discussion of how this work would benefit other listed species or resident fishes. Based on the information in the proposal and the photographs provided, the Alder Creek crossings appeared to be the priority candidates for replacement.

We therefore recommend that this project be funded in part with Alder Creek receiving top priority, with the understanding that additional funding may be warranted if stronger evidence for benefits to anadromous species can be presented for the Beaver Creek and Clear Creek sites.

The ISRP is not requesting a response, but the proposal would be improved by addressing the following comments:

This project would reconnect a 0.6 mile-long oxbow that was created when state route 507 bisected Nason Creek. The proposal does a good job of describing the history of habitat alteration in Nason Creek, especially along its lower reaches. Using two long arch culverts, one at the inlet and one at the outlet of the oxbow, the site would become a large, slow flowing side-channel of the mainstream that would be connected at nearly all flows. Details of the reconnection project and the hydrological surveys were exceptionally well described. EDT analysis indicated that reconnecting this oxbow would increase Chinook productivity in the entire watershed by 25-50%.

The technical background section described two alternatives for restoring this site, neither of which was preferred. Including this information was peripheral to the overall proposal and was not particularly helpful. Additionally, the background section did not provide any estimates of the number of Chinook or steelhead currently spawning in Nason Creek, or an estimate of the additional number of adults that might result from this restoration project, which could have been done using EDT.

The proposal includes only plans for implementation modeling, but not effectiveness monitoring. This is unfortunate, because the restoration design is such that estimates of fish coming in and fish going out of either end of the oxbow could be obtained with appropriate traps, and PIT-tagging can be used to estimate downstream survival. This site would provide an excellent place to test the EDT model prediction of a 25-50% increase in Chinook smolt yield.

Overall, the ISRP was impressed with this proposal.

This proposal does not adequately justify the actions proposed in terms of specific benefits to fish and wildlife and description of methods and, thus, does not meet the ISRP review criteria. This proposal could have made a stronger case for replacing the culverts in question if it summarized what species would benefit from the passage improvements for each watershed, and estimated how many miles of stream would potentially be made available after road crossings were fixed. This work would replace 43 culverts in the Wenatchee subbasin. Only one of those culverts - Mill Creek in the Peshastin watershed - is described. The Mill Creek culvert is located near the mouth of the stream and is claimed to block steelhead spawning migrations and possibly other anadromous or adfluvial salmonids, although steelhead is the only species apart from westslope cutthroat that occurs in Mill Creek according to the distribution maps supplied with the proposal. No details about the other 42 culverts are given, however the map in attachment B shows they are located in clusters on Derby, Brender, Ruby, and East Fork Mission Creeks.

This proposal should have provided information about habitat conditions upstream from the fish barriers in these streams so that replacing the problem culverts would be better justified. The proposal should have also described what structures will replace the culverts and how fish passage at all life history stages will be assured. Will modular bridges be used, bottomless arch culverts, low-water crossings (crossings that are inundated at high flow), or other types of road crossing structures? The narrative says that the Upper Columbia River Regional Technical Team's prioritization scheme will influence the order of repairing the crossings, but details are not provided. If some streams have a higher priority for passage improvements than others, the rationale should be given. It is unlikely that Level 1 monitoring will reveal whether the fish passage improvements achieve their desired objective unless actual stream surveys are carried out post-replacement.