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

The “Annual Unit Runoff (dam3/km2) for a 50% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 50% Probability of exceedence annual unit runoff.

The “Annual Unit Runoff (dam3/km2) for a 70% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 70% Probability of exceedence annual unit runoff.

The “Annual Unit Runoff (dam3/km2) for a 25% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 25% Probability of exceedence annual unit runoff.

The “Annual Unit Runoff (dam3/km2) for a 80% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 80% Probability of exceedence annual unit runoff.

The “Annual Unit Runoff (dam3/km2) for a 10% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 10% Probability of exceedence annual unit runoff.

The “Stations used for Unit Runoff Analysis” dataset is a point data set for select hydrological stations that covers the extent of Canada.

The “Annual Unit Runoff (dam3/km2) for a 90% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 90% Probability of exceedence annual unit runoff.

The “Annual Unit Runoff (dam3/km2) for a 75% Probability of Exceedence” dataset is a line data set that covers the extent of Canada. It shows the 75% Probability of exceedence annual unit runoff.

This product provides the variability index for selected drainage regions in Canada. Variability is measured using a coefficient of variation (CV) to compare all months over a 42-year time period and is a measure of the dispersion or variation in the monthly yield values from 1971 to 2013 (and 1971 to 2012 for drainage region 1). It is defined as the ratio of the standard deviation to the mean or the standard deviation divided by the mean, with higher CVs indicating more variability in monthly water yields. The monthly variability was not calculated for drainage regions 5, 7, 8, 16, 17, 18, or the Labrador portion of 25.