Factors contributing to the salinity of lakes, Riske Creek region, south-central British Columbia, Canada

The objective of this study was to determine the primary factors that contribute to the salinity of lakes located within the Riske Creek region of south-central British Columbia, Canada. The Riske Creek region contains numerous lakes with a salinity range of 0–10.8 ppt with high and low salinity lakes co-existing in close proximity to one another. The region is of extreme ecological importance because it is located on the Pacific flyway and serves as a major breeding ground for a number of waterfowl species. Water budgets, lake water chemistry and cation (Ca 2+, Mg 2+, Na+ and K+) interstitial water composition were determine for 9 lakes, 3 oligosaline (0 ppt), 3 mesosaline (0.4–1.0 ppt) and 3 euryhaline (2.7–5.3 ppt) to determine if evapo-precipitive or saline groundwater inputs were the primary determinants of lake salinity. Lake water budgets indicated that meso and euryhaline lakes were in a close to zero or negative water balance whereas the 3 oligosaline lakes were in a positive water balance. Groundwater saline inputs, as measured by lake sediment interstitial water cation concentrations, indicated that groundwater made only minor contributions to lake salinity. Water budget calculations and sediment interstitial water chemistry suggest that lakes are saline largely due to evaporative processes.