The recent winter of the hydrological year 2024-2025 in the Lake Kinneret Watershed (LKW), has been characterized by very low precipitation and in turn very low discharges, with few to no flooding events in various streams. We set to examine nutrient dynamics in the LKW during this period focusing on the main nutrients: N and P. We characterized the association in time and space between various N and P species, and stream attributes such as, discharge, suspended matter, and other physico-chemical parameters. The recent winter trends are compared with long-term trends arising from detailed monitoring data over the last 20 years.
Taking the Jordan River and the Meshushim stream as study cases, in both stream systems, discharge was very low compared to average years, with several minor increases that lasted a few days at most. While low nutrient fluxes in these streams relative to average winters is expected, following low winter discharges, how stream nutrient concentrations ratios will change is less trivial. The two stream systems show different responses to the low precipitation- low discharge winter. In the Meshushim total and dissolved N and P remain at background, summer baseflow levels, and during minor increased discharge events, elevated concentrations exceed long-term average concentrations. This behavior contrasts long-term trends where concentrations drop below baseflow level reflecting dilution stronger than source leaching. The Jordan shows different behavior with decreasing of concentrations relative to background levels, and this is again in contrast to long-term trends. The differences between the Meshushim and Joradn is also reflected in N:P ratios. These differences both in long-term trends and in the contrasting response during the recent winter are interpreted to reflect not only the different size of the basins but also the significant role of the Hula in regulating nutrient concentrations in the Jordan River during winters.