| Citation |
Epp, P. and G. Andrusak (2012) Report: Results of 2011 West Kettle River, Kettle River and Granby River Flow, Temperature, Useable Fish Habitat & Snorkel Enumeration Survey For Kettle River Fish Protection Planning, Trout Creek Hydrology & Soils and Redfish Consulting Ltd. Prepared for the Ministry of Natural Resource Operations. |
| Abstract/Description or Keywords |
The Kettle River Watershed supports several wild fish stocks, including rainbow trout (Oncorhynchus mykiss), whitefish (Prosopium williamsoni) and 2 identified Species at Risk. It has a history of severe low flows and high water temperatures, ranging in the sub-lethal to lethal limits for salmonids (19-26 °C) More than 6 fish kills involving trout and whitefish have been recorded in the watershed over the past 2 decades. These kills occurred during summer conditions when flows were very low and water temperatures exceeded 20 C° (MoE Files 2009). During the last two decades the quality of the Kettle River rainbow trout fishery has deteriorated due to low abundance and small size. A number of fisheries assessments have identified issues such as water and land practices, available habitat, recruitment, over-fishing, low seasonal flows and high seasonal temperatures as having severely limited rainbow trout abundance. .Consequently, today this population appears depressed (Sebastian 1989; Oliver 2001, Oliver 2002, Andrusak 2007). The Kettle River watershed is considered to be a high priority for fish protection planning given the deteriorating fishery. This 2011 flow and habitat monitoring program continues and expands the existing information sources for fish protection planning as follows: eight continuous seasonal flow measurements sites have been established in the Kettle River watershed to supplement the information available through Water Survey of Canada (WSC) and the US Geological Service (USGS) to determine if there are changes in flow patterns along the rivers that could be attributed to localized water use. The flow measurement sites incorporate temperature monitoring to determine how river temperature varies with flow and air temperature. Useable fish habitat width at varying flows was also determined for each new site to demonstrate how useable fish habitat varies as flows generally diminish during the summer and fall months. Lastly, additional information from annual fish index monitoring and habitat suitability information collected on target species is provided. The report summarizes results of the annual snorkel surveys for rainbow trout and whitefish conducted on the Kettle and West Kettle Rivers since 2001, providing an overview of trends from index sites. In addition, habitat use and preference criteria for speckled dace were used to provide habitat-flow information for this SARA listed species. The results and observations from the 2011 Kettle River flow / temperature / habitat and snorkel enumeration can be summarized as follows: Flows: _ Flows are highly synchronized within sub-basins (West Kettle, Upper Kettle, Lower Kettle and Granby), with patterns of storm peaks and periods of low flows well replicated throughout the watershed. _ River flows were very high (1 in 10 year return frequency) at or above mean flows in July, but diminished to median flow levels by late August and continued to decline to low flows with a 1 in 4 year return frequency by late September. _ The lowest flows ranged from 5 to 6% Long Term mean annual discharge (LTmad) in the upper West Kettle and Granby Rivers and from 7 to 9%LTmad in the lower West Kettle and Kettle Rivers. _ The flow patterns among stations in the Granby and Lower Kettle sub-basins indicate periods at downstream sites that are lower than flows upstream. This is interpreted as evidence that downstream flows are being reduced by upstream water use. Temperatures: _ River temperatures were lower than in 2010, only reaching as high as 22 oC maximum daily temperature in August. River temperatures vary by site in each river, with a differences of 2 to 3 oC in August between the upstream and downstream sites. _ River temperatures are well correlated with mean air temperature, with the highest river temperatures measured on the days when mean air temperature exceeds 22 oC. _ River temperatures are also highly synchronized within and among sub-basins, with periods of high and low water temperatures well replicated throughout the watershed. _ River temperatures show up to 6 oC in diurnal fluctuation, with the highest water temperatures in later afternoon and lowest temperatures at about 7:00 A.M. to 9:00 A.M. _ Temperature and higher flow correlation data is available for the WSC station near Westbridge in 2011. This data does appear to indicate that higher flows do result in somewhat lower river temperatures on high air temperature days, but only when the flow was higher than 12 m3/sec. _ Consistent with 2010, there appears to be little if any correlation between river temperature and flow at the moderate to low flows that are common from mid July into September. Higher river temperatures commonly occur at low flows during this period, but this is mostly coincidental as periods of lower flows are associated with hot and dry weather conditions. Useable Habit Width / Flow: _ Useable habitat width vs. flow analyses show that for rainbow trout parr, useable habitat width is optimized or close to optimized values when flows are at 20%LTmad. _ Useable habitat width is significantly lower at flows of 10%LTmad, but riffle velocities still tend to be satisfactory at these flows. _ Useable habitat width declines rapidly as flows decrease further below 10% mad, with both riffle velocities and riffle depths declining rapidly. Rainbow trout issues: _ Lack of deep, fast water habitat (especially pools) limits rainbow trout abundance _ Late summer water temperatures can become lethal to rainbow trout _ Flows < 10%LTmad combined with high summer temperatures are problematic for trout and whitefish and mortalities can be expected at temperatures > 24°C if prolonged. _ Snorkel survey data provides population trend data but is of little use for interpreting fish flow requirements. _ Low flows and high temperatures most likely influence trout growth and survival but there are a number of other factors related to habitat such as pool limitation that also influence growth and survival. Annual snorkel counts: _ The Kettle River demonstrated considerable increases in rainbow trout numbers based on snorkel surveys at annual index sites _ The West Kettle River numbers declined substantially in both index sites _ Granby River counts demonstrated a slight decline in overall fish numbers in 2011 compared to 2010. _ Mark –recapture data collected on snorkel efficiencies in the West Kettle River for deriving abundance estimates may be biased as a result of high flow conditions in the summer of 2011. _ It is unsure whether trends in fish populations from snorkel surveys are a result of flow related issues on these systems. Nevertheless, data does support the fact that flows below < 10%LTmad, combined with high temperatures are problematic for fish in these systems. |
