Valley Water: Surface Water Data Portal

The Flood Watch toggle will only display the sensors that have a threshold or forecast.

Thresholds indicate locations where there are known and estimated flood risks. The severity of the current and future forecast for the location is indicated by the color coding. Thresholds were developed using the best available information at the time and are subject to inaccuracies. Stream forecasts are available in select locations and are based on future weather conditions. Forecasts may be highly variable and should be used with caution.

Valley Water operates a forecasting tool to estimate future water levels. These predictions are heavily influenced by rain forecasts provided by third parties and are subject to uncertainty. Please use the data provided with caution, as its purpose is to provide an additional layer of data to inform decisions. We are continuously working to improve the accuracy of predictions and adding new forecast locations. Additional forecasts for our river systems are done by the California Nevada River Forecast Center.

Notifications are still being developed and will be available in a later update to the website.

Valley Water operates different types of sensors to collect surface water data. Here you can toggle between the three main types of sensors: stream, reservoir, and rain. Rain sensors operate by measuring accumulated rainfall through the use of small tipping buckets. For rainfall data, YTD implies the water year from October through September of the following year. Errors can be introduced when there is heavy wind or debris blocking the collector. The stream and reservoir sensors directly measure water level, while both flow and storage are inferred through field measurements and bathymetric surveys, which can introduce some error. Typically, storage errors are small, while flow errors are larger. More information about stream gaging can be found on the USGS Website.

Data are reviewed and quality controlled by staff during the summer for the previous year. Much of the recent data are raw and may include transmission or instrument malfunction. Data gaps and errors exist in the dataset and users should exercise caution. This site displays available data for active sensors. To seek all available data, please contact our public records request.