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OpenCDSS / HydroBase

HydroBase is the State of Colorado's database for water resources data. Use the following links to download HydroBase software and database. Local installation is typically only needed for modeling and advanced data analysis.

Additional HydroBase information and resources are available below:

General/User Information

The following sections provide background and information that is useful to HydroBase database users. HydroBase users generally fall into two categories:

  • General data users
  • Modelers
    • often download and install HydroBase on a local computer
    • SQL Server Express and HydroBase Database Manager software also are installed
    • once installed, use software such as TSTool and StateDMI to automate processing HydroBase data into StateCU and StateMod model files

Downloading and installing HydroBase on a local computer is generally discouraged unless there is a need to create CDSS model files or perform other advanced analysis. A higher level of skill is often necessary to use HydroBase on a local computer.


HydroBase is the State of Colorado's database for water resources data, including structure and station data, water rights, and many other data types. HydroBase has a long history of providing data to State of Colorado staff and the public, and is central to water planning and administration in Colorado.

Colorado's Decision Support Systems (CDSS) relies on HydroBase for input to models including StateCU and StateMod. The TSTool and StateDMI software automate processing of "command files" to create model input files.

User Documentation


HydroBase currently does not have a specific license assigned. It is made available to the public by the State of Colorado.

Report an Issue

Contact Doug Stenzel at

Developer Information

HydroBase is maintained by the State of Colorado.

Software Developers

The State of Colorado has designated the following as product contacts for development.

Person GitHub User Role/Comment
Doug Stenzel (DWR-SEO ) State of Colorado DWR lead
Brian Macpherson (CWCB) macphersonbr State of Colorado CWCB lead

Developer Documentation

HydroBase is maintained by the State of Colorado. See the User Documentation for additional information resources.

Development Environment

HydroBase uses Microsoft SQL Server. The downloadable CDSS version of HydroBase uses SQL Server Express, which is limited to 10 GB in size. This database is read-only and snapshots are made available periodically to reflect annual data updates.

Version Control

HydroBase snapshot releases use a name HydroBase_CO_YYYYMMDD to reflect the database release date. The version number should be used when reporting issues with local HydroBase installations. The appropriate snapshot can be used with specific projects and software testing.

Adding an Issue

Contact Doug Stenzel at


HydroBase database and software integration are tested differently by each software tool that uses HydroBase. See the developer documentation for each CDSS software tool. HydroBase snapshots from the archive can be downloaded and used as needed to implement software testing specific to a HydroBase version.