StormTac Database v.2023-10-10
StormTac Database compiles e.g unique annual flow-weighted data calculated by e.g. NURP, NSQD and the BMP database, as well as from other literature data. The data is updated continuously (weekly/monthly) with new data from more substances, land uses and treatment facilities.

With the StormTac Database you can for example filtrate and search for certain land uses, substances and facilities. You are free use the data with reference to the database.

From the menu tab “Stormwater concentrations” you can also filtrate references from where in the World the data was sampled and from within which years.

The data is implemented in the stormwater and receiving water application StormTac Web ( with default recommended typical values that can be changed by the user to reflect site-specific conditions.

Please contact us by e-mail to to send us new data for possible addition to the database or if you would like to request for a License of the model StormTac Web. See prices or click on more information to find out more about StormTac Web.

To calculate total pollutant transport in e.g. stormwater sewers or ditches, both stormwater and baseflow needs to be calculated, using land use specific runoff coefficients for stormwater and infiltration coefficients for baseflow (i.e. inleaching groundwater and attached drainage). If only stormwater concentration is used, the total calculated pollutant load from the studied area will generally be too low and the calculated pollutant concentration too high.

To design stormwater treatment facilities and to calculate their reduction efficiencies, the total incoming pollutant concentration to the facility is needed as input, as well as other site-specific input parameters such as the size of the facility in relation to its reduced watershed area, the share of vegetation, bypass fraction, hydraulic efficiency (form) and the flow detention volume over the permanent volume or its emptying time.

Please do not use the general data from this database for this type of calculations! An application such as StormTac Web is recommended for these calculations and includes many parameters not presented in this data base.

StormTac Database (2023). Stormwater, baseflow, surface water and wastewater database, v.2023-10-10. StormTac Corporation.

Click on the menu tabs to come to the responding data.
All the values in the database are presented with two value figures, reflecting uncertainties.
Data in Red text indicates more uncertain values.
Data marked with * includes comments.
Land uses and facilities in Orange text are clickable, presenting references with data.
Full references are presented by hovering the pointer over the references. By clicking on a reference, it becomes possible to copy.

If measurement data is below the detection limit (less-than values), the detection limit value has been halved when calculating the median and mean values. If the data is presented as an interval, the mean of the values has been used when calculated the median and mean values.

The typical values in the heading rows have been estimated from the compiled reference data, justified after comparison with data from similar land uses or treatment facilities, calibrated to case studies and adjusted for time trends.

Where reference data is missing, the typical values have been estimated from comparison with data from similar land uses or treatment facilities.

* StormTac Database are best experienced with the latest versions of Google Chrome and Firefox as well as Microsoft Edge.