Wahleach Project Water Use Plan Lower Jones Creek ... - BC Hydro

and the April 25 and April 29 capture efficiency results (0.565 and 0.336 respectively) were the
highest on record since monitoring was initiated (Table 12). The increased efficiencies from
these three tests increased the mean for this year from about 10% observed in previous years
to about 25% (Table 12).
Table 12 Summary of Jones Creek capture efficiencies during the WUP monitoring program.
2008 -09 2007 - 08 2006 - 07 2005 - 06
Test Chum Pink Chum Chum Pink Chum
1 11.3% 11.4% 13.2% 13.6% 15.0% 20.5%
2 6.5% 10.6% 12.1% 13.0% 15.3%
3 56.5% 1.3% 9.5% 18.3% 8.0%
4 33.6% 6.2% 8.2% 12.1% 6.8%
5 19.3% 15.2% 12.1% 18.4% 18.9%
6 8.4%
7 10.7%
Mean 25.4% 9.1% 13.2% 11.1% 15.4% 13.9%
Note: Bold, italicized efficiencies shown for 2008-09 were observed during the dual-trap configuration
described in this report.
5.4 Flow and Channel Morphology
Flows in Lower Jones Creek were periodically below the target flow of 1.1cms between
September 15 and November 30 (Figure 5). Sub-target flows were measured between
September 15 and October 30, 2008 while flows remained above 1.1cms for the remainder of
the spawning period after October 30. During the period of sub-target flows, water in Lower
Jones was augmented from the siphon at Jones Lake Reservoir and the diversion at Boulder
Creek. Metered flows of water from the siphon throughout this period indicated that
approximately 50 to 60 % of the flow in Lower Jones Creek was being provided from the siphon.
Continuous flow data for the spawning period is not available since the hydrometric station was
not in service. The actual flows between the dates of our flow measurements are unknown.
There were 12 flow measurements taken between Sept. 12 and Oct. 30 and 8 were below 1.1
cms and 4 were above (Figure 5). Without the continuous flow data it is not clear exactly how
long flows were above or below the 1.1 cms target.
The low flows in Lower Jones Creek during the early and peak stages of spawning did not
appear to prohibit access to spawning areas in the creek. Chum salmon were observed actively
spawning in all areas of the creek during the sub-target flow period although the majority of the
fish spawned in the lower sections of the creek.
Although there have been no barriers to fish access identified during low flow conditions over
the past few years, potential impacts do exist. Spawning habitat availability is reduced with
lower flows, and could lead to crowding and redd superimposition. Fish may also undergo
increased stress migrating through shallow waters, and could be more susceptible to predation.
5.5 BC Hydro Enhancement Monitoring
Over the past several years BC Hydro has undertaken habitat enhancement in lower Jones
Creek and Lorenzetti Creek. These enhancements include removal of the diversion weirs in
Lower Jones Creek and the construction of off-channel rearing habitat and spawning platforms
Lower Jones Creek Fish Productivity Monitoring 2008-2009 26