F20 Arrow Lakes Reservoir nutrient restoration program
To address the nutrient losses in Arrow Lakes Reservoir, as a result of the construction of the Mica and Revelstoke Dams, a bottom-up approach is taken with the addition of nutrients (nitrogen and phosphorus in the form of liquid agricultural grade fertilizer), to support phytoplankton populations that are suitable for the production of Daphnia, a main food source for Kokanee.
Final report: executive summary
Nutrient additions, in the form of liquid agricultural grade fertilizer occurred in Upper Arrow following the same methods as recent years. In total, 40.5 MT of phosphorus and 248.8 MT of nitrogen were added to the Reservoir between early May and end of September. The annual tonnes of phosphorus from fertilizer additions has been around 40 MT since 2016 (this is the fourth year of holding similar loading rates). The 2019 schedule was only adjusted once in mid-August, where the blend was adjusted to only nitrogen, this was due to nitrate levels reported below detection in Lower Arrow water samples.
The April- September daily mean flow for Arrow (total outflow) in 2019 was low compared to the previous eight years. These lower flows were observed in the early summer, from April to June, as well as late August in September. The flows in July and early August were near average. The air temperature in winter of 2018/2019 and spring, summer and fall of 2019 were all below average, as well the lowest temperatures (since 1992) in February were noted in 2019, where the monthly mean temperature was below 5 °C.
Click the provincial database link below to read the full final report for this project.
Angler residence, targeted species, catch rate and size of angler-harvested fish from Arrow Lakes Reservoir in 2019 report: http://a100.gov.bc.ca/pub/acat/public/viewReport.do?reportId=58652