The North America Surface Water Values point dataset contains the current water level and stream flow values as recorded by Canadian and USA hydrometric gauging station locations.
Daily values are recorded as well as comparisons with historical measurements, including difference in values from the previous day, the mean level for that calendar date, the annual mean water level, and maximum and minumum recorded levels. Percentile values based on historical average for both water level and stream flow are also included.
Real-time gauging station data for Canada is available here: https://wateroffice.ec.gc.ca/search/statistics_e.html
Real-time gauging station data for the United States is available here: https://waterservices.usgs.gov/rest/Statistics-Service.html