This space will be used to provide important information about how to use and interpret information presented on these report cards, and clarify important assumptions used in each selected EDT analysis. In future monitoring cycles, managers will use this space to describe important management milestones that occurred in each reporting unit during the identified status and trend year. For example, managers can identify major fish passage or habitat restoration projects implemented in a given assessment unit that explain measurable changes in habitat performance relative to the prior Status and Trend Year. Managers may also use this space to summarize progress towards habitat objectives at different spatial scales.

Species Distribution Assumptions used in EDT:

• Summer/fall Chinook spawn only in selected reaches in the mainstem {{ctrl.subbasin}} and the Similkameen River, there is now spawning in smaller tributaries.
• Steelhead spawn in selected mainstem and tributary reaches in the model network, which represents the known and potential extent of anadromous habitat in the subbasin. Some reaches were excluded from spawning habitat because they lack historical potential and are unlikely to support spawning in the future.

Limiting Factor Reporting: EDT survival factors are analogous to US Forest Service habitat limiting factors. A survival factor can be a habitat limiting factor if it is degraded and negatively impacts habitat performance. The user can access survival factor reporting as follows:

• EDT survival factor performance is summarized at two spatial scales, assessment unit and reach.
• Use the map to the left to navigate to the desired spatial unit, then click the Habitat Trends tab.
• The assessment unit report identifies the top five survival factors in the selected assessment unit based on their effect on habitat performance (factor weight).
• The factor weight score represents the percent of productivity loss attributable to each survival factor.
• % of Template score describes the current survival faction function as a proportion of the historical ideal, the smaller the %, the greater the potential lift from restoration.
• The reach report describes all the above information at the reach scale and describes the relative effect of each survival factor on life stage survival in the selected reach.

Some assessment units have high priority survival factors with % of Template ratings > 100%, most commonly for channel stability. In those cases, the timing of flow-related channel stability effects has changed relative to the template scenario resulting in a net beneficial effect on species abundance. However, the survival factor may still have a negative impact on habitat performance overall.

Using Level of Proof to evaluate data quality: This report presents two types of data quality scores, Level of Proof ratings and weighted Level of Proof Scores.

Level of Proof Ratings

Describe the quality of data and information used to parameterize individual habitat attributes entered into the model, used to summarize data quality at the subbasin and assessment unit level. See the “How Good is the Information…” bar charts on the Performance Summary tab. Individual reach level attribute ratings can also be viewed by hovering your cursor over the Attribute Rating bar graph on the Attribute & Monitoring Data tab.

Weighted Level of Proof Scores

Reported by survival factor at the assessment unit and reach scales. A combined score for each survival factor that weights component LOP ratings based on the relative effect of that habitat attribute on survival factor performance. These scores can be used to identify habitat priorities that may benefit from additional data validation.

Rating definitions:

1. Best: Attribute based on empirical data representative of reach-level habitat conditions
2. Very good: Attribute based on high-confidence modeled inputs, aerial imagery interpretation, or similar sources
3. Good: Attribute based on extrapolated conditions from similar reaches, or on well-supported professional knowledge, theoretical basis with some support from observations
4. Fair: Rating based on professional knowledge, with some empirical support
5. Poor: Hypothetical attribute rating, based on professional judgement with no empirical data support

Status and Trend Year 2040 Results Disclaimer:

The Status and Trend Year 2040 scenario considers possible future temperature and flow conditions during the period from 2030 to 2059. This is a proof of concept analysis that only considers potential temperature and hydrologic change, all other EDT habitat attributes are identical to the 2017 scenario. The scenario results may be helpful for understanding flow and temperature effects on fish habitat performance and planning actions to mitigate or offset those effects. However, climate change is likely to have profound effects on other factors that affect habitat conditions, including biological community structure and watershed processes. These changes are likely to affect fish habitat in ways that we have not attempted to characterize for this analysis. We do not currently have sufficient information to incorporate these variables into an EDT analysis. We also did not attempt to predict how those changes could be mitigated by watershed process restoration and changes in hatchery practices, water management, and other political and management policies. Therefore, persons using the 2040 Status and Trend Year results to make planning decisions should do so with a full understanding of the assumptions and limitations of this analysis.

Climate Change Analysis Methods and Assumptions:

The Status and Trend Year: 2040 scenario considers projected streamflow and temperature conditions for the period from 2030 to 2059. This analysis used the 2017 scenario as a base case, with hypothetical future conditions ratings for the following EDT habitat attributes:

• Flow: Inter-annual High Flow Variation
• Flow: Inter-annual Low Flow Variation
• Flow: Intra-annual Variation
• Temperature: Daily Maximum
• Temperature: Daily Minimum
• Bed Scour (i.e. the change in monthly distribution of bed scour events based on projected future flow conditions)

The climate change analysis was developed by the Colville Tribes EDT consultants using two primary data sources. Future streamflow conditions were derived from modeled daily streamflows for the U.S. portion of the Okanogan subbasin for the period from 2030–2059. These streamflow projections were developed by the U.S. Forest Service Rocky Mountain Research Station (RMRS) using the Variable Infiltration Capacity (VIC) macroscale hydrologic model as part of the Western U.S. Streamflow Metrics (WUSSM) dataset. Our consultants used the VIC model outputs to derive EDT flow attribute ratings for the U.S. portion of the Okanogan reach network. Future water temperature conditions were modeled by our consultants using the STARS/SSN statistical modeling platform. They used this platform to build a spatial statistical model for the Okanogan EDT reach network using climate model output and watershed covariates relevant to streamflow and temperature (e.g. elevation, upstream drainage area, aspect). They calibrated the model using the historical climatic record for the period from 1916 to 1946, consistent with the WUSSM project. Future temperature conditions were modeled using water from temperature data collected by OBMEP at five continuous gauge locations between 2008 and 2012. Those sites were selected based on the completeness of the data set. Missing data records were interpolated using a multivariate correlation script for the R statistical software package provided by Dan Isaak with RMRS.

The 2040 scenario was developed only for the U.S. portion of the subbasin. WUSSM model outputs and STARS/SSN watershed covariates were not available for the Canadian portion of the subbasin.

We did not attempt to project future conditions for any habitat attributes used in the EDT model other than those described above. Climate change is likely to alter watershed conditions in ways that could fundamentally affect the distribution of habitat types, sediment transport and delivery, and other watershed processes in ways that we have not attempted to characterize at this time. The 2040 scenario results are intended to provide a proof of concept for the use of EDT as a tool for evaluating the potential effects of future climate conditions on habitat performance for ESA-listed salmon and steelhead. The results should be interpreted and applied with appropriate caution.