1. Objectives

The long-term goal of this project is to produce credible scientific insights for understanding the role of alluvial aquifers and associated hyporheic exchange relative to conservation of Pacific Northwest salmonids. This improved understanding was to provide a foundation for development of improved restoration strategies including location and design of projects. Unfortunately, the three major objectives are broadly stated and lack specific description of their intent and the specific hypotheses on which they are based. While the objectives are clearly worded, they are not quantitative or time bound. They function as main goal statements. For instance, the first objective was to understand the distribution of Chinook and summer steelhead, but there was no identification of the specific hyporheic attributes related to the distribution of the fish. The overarching hypothesis is equally broad and vague, simply stating that hyporheic exchange is important in the distribution of anadromous salmonids. Sub-hypotheses are provided in the description of current work, but these also are broadly stated and lack sufficient detail.

2. Methods

The proponents appear to have organized a comprehensive program. Previous annual reports describe their specific research measurements and analyses. Not only are the scientific methods sound, an Adaptive Management strategy and active Public Outreach activities are also key project components.

3. Results

The project has provided a substantial body of research on hyporheic exchange and its relation to the ecology of anadromous salmonids and habitat restoration. The project summary report describes the completion of Phase Two of a three-part project. Explanations of the measurements and analyses were provided in previous annual reports. The summary provides only general annual end dates for project activities.

While the body of research is scientifically sound, several conclusions are questionable. The researchers conclude that hyporheic exchange is an important consideration for management of spawning habitats because redds are found upstream of nick points. The research did not actually measure hyporheic exchange associated with the location of redds. Protection and restoration of a hyporheic exchange is warranted, but caution should be used in interpreting these results.

The Meacham Creek Restoration Project resulted in increased warming through the restoration reach. The project leaders attributed this to removal of riparian shade to allow large equipment to realign the channel. While this hypothesis may be correct, caution should be used in interpreting the results. Other physical processes could be responsible for the observed warming. The final project summary simply states that lack of shade counterbalanced the cooling effect without providing a qualifying statement that this was a hypothetical conclusion.

The hydrological model of hyporheic exchange, which was developed, is a beneficial tool in managing stream temperature. The inclusion of components addressing both shade and hyporheic exchange strengthens the model, and both are used by other researchers in modeling hyporheic processes.

The project has significant benefits for guidance for water temperature management and habitat restoration throughout the region. The proponents have made some interesting discoveries that have general benefits for restoration if a hyporheic perspective could be more broadly applied. The summary describes the benefit to habitat monitoring programs but also identifies a link between their hyporheic research and the First Foods management approach of the CTUIR River Vision. This linkage between habitat restoration in the First Foods concept is extremely important and should be highlighted in monitoring and presentations of their findings in the future. The summary would be strengthened by identifying additional outreach activities, which are provided in previous annual reports.

4. 2017 Research Plan uncertainties validation

The project addresses Critical Uncertainties (CUs) associated with the efficacy of stream and habitat restoration efforts [A 1.1, 1.2, 1.4, 2.2], while providing additional knowledge relevant to focal species response to restoration actions [E 1.1], and stream temperature response to climate change [J 1.3, 2.1].

The project summary briefly explained linkages between the research and the CUs but did not address whether the linkage was direct or indirect. In general, the ISRP agrees with the general description of linkages. One CU listed in the Council’s 2017 Research Plan Database (B. Mainstem habitat) was not included in the project summary. We agree that it is not closely linked to this research.

 

The project has provided important findings and potential general applications for a hyporheic perspective in restoration planning. After a number of years, however, results are less detailed than originally projected and, to date, are limited to the specific location studied. More information on biological responses and restoration applications would be useful. The proponents are asked to provide: • A quantitative description of the influence of hyporheic exchange on redd locations and the causes for warming in the restored reach of Meacham Creek; • A description of how past outreach and guidance has been incorporated into better management practices; and • Specific hypotheses, quantitative objectives, timelines, expected products, and the application of products for improved management practices associated with Phase 3 of the project. Note: The proponents provided an excellent response to a previous set of qualifications (i.e., 2007-252-00, Response to ISRP Memo dated 11/6/2013). They provided an outstanding example of direct, informative answers to questions raised in a previous ISRP request for response.