The State of Colorado's Consumptive Use Model (StateCU) was developed to estimate and report crop consumptive use within the state. It consists of a FORTRAN-based computer program and an associated graphical user interface. The crop consumptive use methods employed in the program and the interface are the Modified Blaney-Criddle, the Original Blaney-Criddle, and the Pochop (for bluegrass only) methods with calculations on a monthly basis and the ASCE Standardized Penman-Monteith method with calculations on a daily basis. Other crop consumptive use methods available when the FORTRAN program is operated independently of the interface include the Penman-Monteith and the Modified Hargreaves methods, operated on a daily time step.
This document was prepared to explain the features and functions of StateCU and presumes the reader has a basic understanding of consumptive use analyses. It is intended for use by engineers, water resource planners, and others involved in water management decision making. Section 2 and Section 3 provide a general description of the model and the necessary instruction to operate StateCU through the graphical user interface. Section 4 through Appendix B provide the detail required to develop datasets and determine consumptive use estimates for a specific area.
StateCU allows several levels of analysis as follows:
- Crop Irrigation Water Requirement by CU Location
- Water Supply Limited Crop Consumptive Use by Structure
- Water Supply Limited Crop Consumptive Use by Structure Considering Ground Water
- Water Supply Limited Crop Consumptive Use by Structure and Priority
StateCU determines crop CU by ‘CU Location’. A CU Location can be a climate station, a specific diversion structure, a combination of diversion structures, or specific area of land. A CU Location is defined by latitude, associated climate stations, crop types, and acreage. A flag in the input control file specifies whether the CU Location is associated with a climate station or structure. The only analyses available with a Climate Station Scenario are the potential crop consumptive use and irrigation water requirement, as reflected by a simplified set of input screens displayed by the graphical user interface. The water supply limited crop consumptive use and other more complex levels of analyses are available under a Structure Scenario.
A number of base datasets are available through the CDSS Website to allow the user to quickly perform StateCU analyses. These include:
- Primary Climate Stations throughout Colorado (climate data not filled)
- Primary Climate Stations for the Western Slope of Colorado (climate data filled)
- Primary Climate Stations for the Arkansas Basin (climate data filled)
- Primary Irrigation Structures in the Gunnison River Basin (climate and diversion data filled)
- Primary Climate Stations for the Rio Grande Basin (climate data filled)
- Primary Irrigation Structures in the Rio Grande Basin (climate and diversion data filled)
- Primary Irrigation Structures in the San Juan/Dolores River Basin (climate and diversion data filled)
- Primary Climate Stations for the South Platte Basin (climate data filled)
- Primary Irrigation Structures in the South Platte Basin (climate and diversion data filled)
- Primary Irrigation Structures in the Upper Colorado River Basin (climate and diversion data filled)
- Primary Irrigation Structures in the White River Basin (climate and diversion data filled)
- Primary Irrigation Structures in the Yampa River Basin (climate and diversion data filled)
StateCU features a scenario creation HydroBase Wizard that allows the user to interactively build a data set to estimate potential consumptive use or water-supply limited consumptive use at user-defined location. The HydroBase Wizard allows the user to extract required input data, such a climate data, diversion records, and crop coefficients; directly from HydroBase through an internet connection.
Following is a general sequence for operating StateCU for a given level of analysis:
- If the provided datasets are not adequate for the desired analysis, the StateCU HydroBase Wizard can be used to interactively create a dataset at a user-defined location, or the CDSS Data Management Interfaces can be used to create more complex datasets interactively with HydroBase, or the necessary input files can be developed following the formats in Section 4 of this report.
- Run the StateCU FORTRAN model through the graphical user interface, as described in Section 2, or stand-alone as described in Section 6.
- Evaluate results by generating output graphs and tables through the graphical user interface, or reviewing output reports generated by the StateCU FORTRAN program as described in Section 5.
The remainder of this document is organized as follows:
This StateCU documentation is licensed using the Creative Commons Attribution International 4.0 (CC BY 4.0) license.
The StateCU software is licensed using the GPL 3 license (see the StateCU software repository).
Source Repository on GitHub
The source files for this documentation are maintained in a GitHub repository: cdss-app-statecu-fortran-doc-user.
This user documentation is maintained in a repository that is separate from StateCU code in order to facilitate contributions by non-programmers.