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OpenCDSS / StateCU

StateCU is the State of Colorado's consumptive use model. Use the following links to download StateCU software.

Additional StateCU information and resources are available below:

General/User Information

The following sections provide background and information that is useful to StateCU users. StateCU users generally fall into two categories: "modelers" and "users of model results". The former develops model input and runs StateCU on the model input dataset whereas the latter may just review models results that someone else has run. The CDSS approach tends to support modelers and there is an opportunity to improve access to model results. This is challenging because model results files can be very large and finding a way to access and view the results, such as on the web, presents technical challenges. A new project has been funded to publish complete StateMod model input and results on the web to facilitate access without needing to run the model, and the results of that project may improve StateCU dataset publishing.


StateCU is the State of Colorado's consumptive use model, which simulates consumptive use for agricultural demands. The model can be run using monthly or daily timestep depending on consumptive use method.

Input to the model consists of consumptive use locations such as climate stations and ditch structures, climate time series, and crop data. Input is typically created using "Data Management Interface" (DMI) software including TSTool and StateDMI, which automate processing of "command files" to create model input files.

Output from StateCU consists of large binary files with time series data, large text file reports, and log and check files, depending on run options. Binary files are often processed using TSTool.

The StateCU GUI (Graphical User Interface) simplifies creation of basic datasets, running datasets, and viewing results. Modelers often use the TSTool and StateDMI software to create input files because the approach is automated and can be repeated, whereas the GUI can be used to edit simpler datasets.

StateCU datasets are not maintained in GitHub and must be downloaded from the CDSS website.

User Documentation


The software is licensed using GPL v3+ license.

Report an Issue

To report an issue or request an enhancement, use the StateCU GitHub repository issues. Software developers will evaluate the issue.

Developer Information

StateCU is written in Fortran (Fortran 77 with some newer code). The OpenCDSS project uses the open source gfortran compiler.

Software Developers

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

Person GitHub User Role/Comment
Kelley Thompson (DWR) kelleythompson State of Colorado lead developer for StateCU
Brian Macpherson (CWCB) macphersonbr State of Colorado CWCB lead
Erin Wilson (WWG) Legacy developer
Steve Malers (OWF) smalers OpenCDSS lead, facilitating implementation of open source project

Developer Documentation

Development Environment

Compilation is via a makefile, although the OpenCDSS project has evaluated using Eclipse Photran. See the Developer Documentation for information about the development environment. Important information includes:

  • A new naming convention is being phased in for executable program names in order to differentiate between 32/64 bit, and Windows/Linux.

Version Control

StateCU code and other electronic assets are housed in the following repositories:

Content Repository Comment
Software code cdss-app-statecu-fortran
Automated tests cdss-app-statecu-fortran-test Envisioned for automated testing.
Developer documentation (MkDocs) cdss-app-statecu-fortran-doc-dev
User documentation (MkDocs) cdss-app-statecu-fortran-doc-user

StateCU software should be updated using a "feature branch" approach as per the OpenCDSS Workflow and StateCU developer documentation.

Adding an Issue

The GitHub issues tool is how developers track issues and communicate on progress. For an overview of using GitHub issues, see "Mastering Issues". The following general procedure should be to used add an issue (bug, enhancement request, question, etc.).

  1. Add a New issue on the StateCU code repository issues page.
    1. The issue title should short and clear, for example "X calculation is incorrect" (which will be indicated as a bug below) or "Need command to ABC" (which will be indicated as an enhancement below).
    2. An issue template (via .github folder in repository) is provided with instructions on how to submit the issue. The template provides default fill-in-the-blank sections that are useful for developers. The template text should be edited as appropriate to explain the issue, and is then submitted. Attachments can be used to provide test data or other useful information. Use a zip file if necessary.
    3. The issue labels should be specified as completely possible. Labels can be adjusted later as necessary. See the OpenCDSS Version Control / GitHub Repository Issues guidelines. If the issue author does not have write permissions on the repository, they will not be able to select issue labels.
      1. Select the issue type as bug, enhancement, or question.
      2. Select the issue priority as low, medium, high, or critical.
      3. Select the issue size as XS, S, M, L, or XS. Note that these are relative sizes and not intended to be detailed hourly estimates.
  2. There is not currently a GitHub project board defined for StateDMI, but it could be added to manage issues.


StateCU testing has traditionally not been automated and has relied on running model datasets to confirm output. Testing is complex due to the following issues:

  1. Software needs to be tested for gfortran.
  2. Software needs to be tested for 32-bit gfortran (current) and 64-bit gfortran (desirable).
  3. Software needs to be tested for Windows and Linux versions (desirable).
  4. Software needs to be tested on small datasets such as the training examples mentioned in documentation (but need to be updated to current CDSS standards).
  5. Software needs to be tested on full datasets such as CDSS basin datasets, for each response file and program option.
    1. For example, check water balance.
  6. Software needs to be tested on daily and monthly datasets.

The StateCU testing approach is being updated to be more rigorous and automated:

  • cdss-app-statecu-fortran-test repository is used for tests, and is under development
  • Rely on TSTool and other software to automate tests
  • The above repository includes scripts to run small tests (examples)
  • The above repository includes scripts to run large tests (full datasets)