Freshwater Indicators

These indicators correspond to flow parameters to which salmon populations are most sensitive. Standardized anomalies of time series from individual gages were then averaged to obtain weighted averages for ecoregions (for which HUC-8 area served as a weighting factor) and for the entire California current (weighted by ecoregion area).;August mean maxium temperature is measured using active USGS gages (waterdata.usgs.gov/nwis/sw) Additional Calculations: Average daily values from 446 gages were used to calculate annual mean maximum Aug temp;Snow-water equivalent data were derived from the California Department of Water Resources snow survey (cdec.water.ca.gov/) and the Natural Resources Conservation Service's SNOTEL sites in WA, OR, CA and ID from sites with records that meet or exceed 30 years in duration (wcc.nrcs.usda.gov/snow/).

Additional Calculations: Anomalies of April 1 snow-water equivalents (SWE) for the CCE, calculated as an area-weighted average of data from the Columbia Glaciated ecoregion. SWE is a measure of the total water available in snowpack. Measurements on April 1st are considered the best indicator of maximum extent of snowpack.;Snow-water equivalent data were derived from the California Department of Water Resources snow survey (cdec.water.ca.gov/) and the Natural Resources Conservation Service's SNOTEL sites in WA, OR, CA and ID from sites with records that meet or exceed 30 years in duration (wcc.nrcs.usda.gov/snow/).

Additional Calculations: Anomalies of April 1 snow-water equivalents (SWE) for the CCE, calculated as an area-weighted average of data from the Columbia Unglaciated ecoregion. SWE is a measure of the total water available in snowpack. Measurements on April 1st are considered the best indicator of maximum extent of snowpack.;Snow-water equivalent data were derived from the California Department of Water Resources snow survey (cdec.water.ca.gov/) and the Natural Resources Conservation Service's SNOTEL sites in WA, OR, CA and ID from sites with records that meet or exceed 30 years in duration (wcc.nrcs.usda.gov/snow/).

Additional Calculations: Anomalies of April 1 snow-water equivalents (SWE) for the CCE, calculated as an area-weighted average of data from the OR & No. CA coastal ecoregion. SWE is a measure of the total water available in snowpack. Measurements on April 1st are considered the best indicator of maximum extent of snowpack.;Snow-water equivalent data were derived from the California Department of Water Resources snow survey (cdec.water.ca.gov/) and the Natural Resources Conservation Service's SNOTEL sites in WA, OR, CA and ID from sites with records that meet or exceed 30 years in duration (wcc.nrcs.usda.gov/snow/).

Additional Calculations: Anomalies of April 1 snow-water equivalents (SWE) for the CCE, calculated as an area-weighted average of data from the Sacramento-San Joaquin ecoregion. SWE is a measure of the total water available in snowpack. Measurements on April 1st are considered the best indicator of maximum extent of snowpack.;Snow-water equivalent data were derived from the California Department of Water Resources snow survey (cdec.water.ca.gov/) and the Natural Resources Conservation Service's SNOTEL sites in WA, OR, CA and ID from sites with records that meet or exceed 30 years in duration (wcc.nrcs.usda.gov/snow/).

Additional Calculations: Anomalies of April 1 snow-water equivalents (SWE) for the CCE, calculated as an area-weighted average of data from the Salish Sea ecoregion. SWE is a measure of the total water available in snowpack. Measurements on April 1st are considered the best indicator of maximum extent of snowpack.;Streamflow is measured using active USGS gages (waterdata.usgs.gov/nwis/sw) with records that meet or exceed 30 years in duration.

Additional Calculations: Average daily values from 213 gages were used to calculate annual 1-day maximum flows. These indicators correspond to flow parameters to which salmon populations are most sensitive. Standardized anomalies of time series from individual gages were then averaged to obtain weighted averages for each of 17 Chinook salmon ESU boundaries (for which HUC-8 area served as a weighting factor).;Streamflow is measured using active USGS gages (waterdata.usgs.gov/nwis/sw) with records that meet or exceed 30 years in duration.

Additional Calculations: Average daily values from 213 gages were used to calculate annual 7-day minimum flows. These indicators correspond to flow parameters to which salmon populations are most sensitive. Standardized anomalies of time series from individual gages were then averaged to obtain weighted averages for each of 17 Chinook salmon ESU boundaries (for which HUC-8 area served as a weighting factor).