Brilliant Upgrade Project: Monitoring of Rainbow Trout Spawning in the Lower Kootenay River, 2007 Report
Author: Golder Associates Ltd
The purpose of the 2007 monitoring program was to verify the environmental assessment conclusion that the flow changes resulting from post-project operations (i.e., the increase in turbinable flow capacity from 510 to 611 m3/s as described in Section 1.1) would not adversely affect rainbow trout spawning in the lower Kootenay River. The specific objectives of the present study were to: • obtain additional information on periodicity, intensity, and distribution of rainbow trout spawning; • monitor physical and operational parameters (i.e., temperature and discharge) during the spawning season; • obtain selected habitat information from 30 rainbow trout redds; • briefly assess whether the 2007 results support the trends and predictions reported in the 2005 report; and, • provide a final conclusion on whether the Brilliant Upgrade Project has had an impact on rainbow trout spawning activities in the lower Kootenay River.
The upgrades to the generation units at BRD do not affect total discharge released from the dam during the peak of the rainbow trout spawning period. As a result, during the Water Licence and Fisheries Authorization application process the potential impacts of the upgrade project on rainbow trout spawning below the dam were predicted to be negligible. The re-routing of water from the spillways through the turbines in the powerplant should not result in measurable effects on downstream flow patterns in the lower Kootenay River within the section used for rainbow trout spawning.
Water temperatures during the 2007 rainbow trout spawning season were within the ranges of previous studies and displayed similar trends when compared to pre-upgrade data. Although discharge through Brilliant Dam was higher during part (mid-April to mid-May) of the 2007 rainbow trout spawning season than discharges recorded during previous years, the overall trend of increasing discharge throughout the study period was similar to pre-upgrade discharge data.
In 2007, the onset and progression towards peak spawning (as determined from the inflection points in Figure 3.7) was similar to patterns recorded in previous years. Peak spawning in all years examined occurred between the beginning of April and mid-May.
Based on redd counts, spawning intensity has been increasing annually in both the Columbia and Kootenay rivers since the late 1990s (Figure 3.5), with the highest total of all study years occurring under post-upgrade conditions (2006). The increase in redds counts in both the Columbia and Kootenay rivers suggests that there are more spawners in the system, either due to an increase in the resident rainbow trout population or a change in the population structure.
During the 2007 rainbow trout spawning season, spawning activity was documented at five of the six known spawning sites in the lower Kootenay River. Redd counts at the Oxbow Area were higher in 2007 than in 2002 (the last rainbow trout spawning season prior to the upgrade), while redd counts at the Bridge Gravel Shoal, Below Boulder Island, Opposite Oxbow Shoal and the Dumpster Area were lower in 2007 than in 2002. Highest numbers of redds have been recorded at the Oxbow Shoal during all study years. Spawning intensity at the Below Boulder Island, Bedrock Outcrop Area, and Dumpster Area sites has fluctuated from year to year. Redds were not recorded at the Dumpster area site during the 1999, 2000, 2003, 2005, and 2006 survey sessions, therefore, the absence of spawning activity at this site in 2007 was not an unusual finding and was not considered a result of the upgrade project.
The comparison of pre- and post-upgrade rainbow trout spawning data indicated that major changes in spawning periodicity, intensity, distribution, or habitat selection did not occur in 2007 following five years of operation of the upgrade project.
The upgrades to the generation units at BRD do not affect total discharge released from the dam during the peak of the rainbow trout spawning period. As a result, during the Water Licence and Fisheries Authorization application process the potential impacts of the upgrade project on rainbow trout spawning below the dam were predicted to be negligible. The re-routing of water from the spillways through the turbines in the powerplant should not result in measurable effects on downstream flow patterns in the lower Kootenay River within the section used for rainbow trout spawning.
Water temperatures during the 2007 rainbow trout spawning season were within the ranges of previous studies and displayed similar trends when compared to pre-upgrade data. Although discharge through Brilliant Dam was higher during part (mid-April to mid-May) of the 2007 rainbow trout spawning season than discharges recorded during previous years, the overall trend of increasing discharge throughout the study period was similar to pre-upgrade discharge data.
In 2007, the onset and progression towards peak spawning (as determined from the inflection points in Figure 3.7) was similar to patterns recorded in previous years. Peak spawning in all years examined occurred between the beginning of April and mid-May.
Based on redd counts, spawning intensity has been increasing annually in both the Columbia and Kootenay rivers since the late 1990s (Figure 3.5), with the highest total of all study years occurring under post-upgrade conditions (2006). The increase in redds counts in both the Columbia and Kootenay rivers suggests that there are more spawners in the system, either due to an increase in the resident rainbow trout population or a change in the population structure.
During the 2007 rainbow trout spawning season, spawning activity was documented at five of the six known spawning sites in the lower Kootenay River. Redd counts at the Oxbow Area were higher in 2007 than in 2002 (the last rainbow trout spawning season prior to the upgrade), while redd counts at the Bridge Gravel Shoal, Below Boulder Island, Opposite Oxbow Shoal and the Dumpster Area were lower in 2007 than in 2002. Highest numbers of redds have been recorded at the Oxbow Shoal during all study years. Spawning intensity at the Below Boulder Island, Bedrock Outcrop Area, and Dumpster Area sites has fluctuated from year to year. Redds were not recorded at the Dumpster area site during the 1999, 2000, 2003, 2005, and 2006 survey sessions, therefore, the absence of spawning activity at this site in 2007 was not an unusual finding and was not considered a result of the upgrade project.
The comparison of pre- and post-upgrade rainbow trout spawning data indicated that major changes in spawning periodicity, intensity, distribution, or habitat selection did not occur in 2007 following five years of operation of the upgrade project.
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Additional Info
Study Years: 2007
Published: 2008
Brilliant Upgrade Project: Monitoring of Rainbow Trout Spawning in the Lower Kootenay River, 2007 Report
Author: Golder Associates Ltd
Tags: Brilliant Dam, Brilliant DamExpansion, Depth, Discharge, Discharge Rates, Distribution, Enumeration, Fish Habitat, Lower Kootenay River, Monitoring Recommendation, Oncorhynchus Mykiss, Rainbow Trout, Redds, Spawning, Spawning Habitat, Velocity, Water Temperature
The purpose of the 2007 monitoring program was to verify the environmental assessment conclusion that the flow changes resulting from post-project operations (i.e., the increase in turbinable flow capacity from 510 to 611 m3/s as described in Section 1.1) would not adversely affect rainbow trout spawning in the lower Kootenay River. The specific objectives of the present study were to:
• obtain additional information on periodicity, intensity, and distribution of rainbow trout spawning;
• monitor physical and operational parameters (i.e., temperature and discharge) during the spawning season;
• obtain selected habitat information from 30 rainbow trout redds;
• briefly assess whether the 2007 results support the trends and predictions reported in the 2005 report; and,
• provide a final conclusion on whether the Brilliant Upgrade Project has had an impact on rainbow trout spawning activities in the lower Kootenay River.
Summary
The upgrades to the generation units at BRD do not affect total discharge released from the dam during the peak of the rainbow trout spawning period. As a result, during the Water Licence and Fisheries Authorization application process the potential impacts of the upgrade project on rainbow trout spawning below the dam were predicted to be negligible. The re-routing of water from the spillways through the turbines in the powerplant should not result in measurable effects on downstream flow patterns in the lower Kootenay River within the section used for rainbow trout spawning.
Water temperatures during the 2007 rainbow trout spawning season were within the ranges of previous studies and displayed similar trends when compared to pre-upgrade data. Although discharge through Brilliant Dam was higher during part (mid-April to mid-May) of the 2007 rainbow trout spawning season than discharges recorded during previous years, the overall trend of increasing discharge throughout the study period was similar to pre-upgrade discharge data.
In 2007, the onset and progression towards peak spawning (as determined from the inflection points in Figure 3.7) was similar to patterns recorded in previous years. Peak spawning in all years examined occurred between the beginning of April and mid-May.
Based on redd counts, spawning intensity has been increasing annually in both the Columbia and Kootenay rivers since the late 1990s (Figure 3.5), with the highest total of all study years occurring under post-upgrade conditions (2006). The increase in redds counts in both the Columbia and Kootenay rivers suggests that there are more spawners in the system, either due to an increase in the resident rainbow trout population or a change in the population structure.
During the 2007 rainbow trout spawning season, spawning activity was documented at five of the six known spawning sites in the lower Kootenay River. Redd counts at the Oxbow Area were higher in 2007 than in 2002 (the last rainbow trout spawning season prior to the upgrade), while redd counts at the Bridge Gravel Shoal, Below Boulder Island, Opposite Oxbow Shoal and the Dumpster Area were lower in 2007 than in 2002. Highest numbers of redds have been recorded at the Oxbow Shoal during all study years. Spawning intensity at the Below Boulder Island, Bedrock Outcrop Area, and Dumpster Area sites has fluctuated from year to year. Redds were not recorded at the Dumpster area site during the 1999, 2000, 2003, 2005, and 2006 survey sessions, therefore, the absence of spawning activity at this site in 2007 was not an unusual finding and was not considered a result of the upgrade project.
The comparison of pre- and post-upgrade rainbow trout spawning data indicated that major changes in spawning periodicity, intensity, distribution, or habitat selection did not occur in 2007 following five years of operation of the upgrade project.