Water Rights History for Structure in Colorado

Hover the cursor over elements of the diagram to view data corresponding to those elements.

The purpose of this diagram is to illustrate how water rights for an irrigation structure change in use over time, in particular to show how water rights originally decreed for irrigation use (IRR) have been changed to municipal use (MUN or ALL) over time. Another purpose is to show how the structure has become an alternate point of diversion due to operational changes in the river basin. The visualization uses a Sankey diagram, which was originally developed to visualize the magnitude of flow between (from/to) nodes in a network. Original water rights appropriations are nodes (vertical bars) on the left, placed at the date when the water right was first put to beneficial use. Aggregates of water rights decreed for specific categories of uses are the bars on the right, placed on the date when the diagram was created. Intermediate nodes indicate when a water right has been transferred from one use to another. The height of each link and node illustrates the decreed amount of the water right.

A water right decree specifies one or more uses for the water right. A water right decree specifies one or more uses for the water right. For the purpose of this visualization, uses are categorized as irrigation (IRR), municipal (MUN/ALL), storage (STO), or other (OTH). See the "use" column in the data.

"Appropriation occurs when a public agency, private person, or business places available unappropriated surface or tributary groundwater to a beneficial use according to procedures prescribed by law. The appropriator must have a plan to divert, store, or otherwise capture, possess and control the water and must specify the amount of water to be used, the type of beneficial use and the locations of diversion or storage and use. Without such a plan, the water right application is considered speculative and is, therefore, prohibited."

"Beneficial use is the basis, measure and limit of a water right. Colorado law broadly defines beneficial use as a lawful appropriation that employs reasonably efficient practices to place water to use."

"Adjudication is the process for obtaining a water court decree for a conditional water right, a finding of reasonable diligence, an absolute water right, an exchange, an augmentation plan, a change of water right, or a right to withdraw nontributary water or Denver Basin groundwater that is outside of a designated groundwater basin."

Definitions are from the Citizen's Guide to Water Law, published by the Colorado Foundation for Water Education.

The data used to create the diagram was queried from the State of Colorado's HydroBase database transactional water rights view and is shown in the Data tab. The following are considered in the process, with references to data table column names:

  • Original appropriations are rows that contain transfer_type = "TF" or transfer_type is not specified. The apro_date is used as the date for the node.
  • Transfers are rows that contain transfer_type="TT".
  • The date that a transfer is adjudicated (made final in water court) is not available in HydroBase. Consequently, the date was determined by reviewing the action_comment column of a "TT" row.
  • Normally, there should be pairs of rows specifying a transfer_type of "TF" and a correlating "TT". However, if only one or the other is supplied, the diagram will appear to show a full illustration of a water right. A lone "TF" will use the apro_date as the original appropriation and end connecting to the aggregation of uses. A lone "TT" will use the action_comment as the date and also connect to the aggregation of uses. The only way one would know that the data did not provide a matching TF/TT pair is when the cursor is hovered over a node that looks like an original appropriation but displays transfer information.
  • Rows with assoc_type of EX (exchange) are processed separately and indicate that water can be taken at the structure in exchange for other water being delivered to another structure in the system. They are omitted from the visualization.
  • Only rows that specify rate_amt, which has units of CFS, are processed.

Limitations of the data, process, and visualization are as follows and may be overcome with additional data and development resources:

  • It is important to note that even though ownership of water rights may be transferred to municipalities or industry, the actual use of some or all of the transferred water in any year may still be for irrigation, for example via water rental programs. Diversion records from HydroBase can be examined to evaluate historical water use. And, not all water that is diverted for use by municipalities is consumed. A significant percentage of the diverted water (typically > 50%) is returned to the system for use by downstream uses, which can include agriculture.
  • It would be helpful if the adjudication date of the transfer were available in HydroBase or a lookup table based on the court case. Unfortunately, the information may need to be determined from reviewing court case documents. Court case dates may include a start and end, and cases may be split or combined over time. The process used for this prototype visualization estimates the adjudication data or transfers.
  • Some records contain rate and volume units. Currently only rate decrees are handled.
  • Handling of AP and EX records is limited. It is important to consider these records separately from transfers because they indicate water external to the original appropriations for the structure. The water rights transactions for the original point of diversion would need to be examined to understand how change of use has occurred at that structure. EX records are omitted from the visualization and AP records are denoted with "Alternate Point" within the popup information.
  • The headings for the data table are from HydroBase. In the future nicer headings can be added, with pop-ups to explain the columns. Refer to the HydroBase database dictionary for more information.
  • Because data such as the adjudication date for transfers needed to be manually added to the water right transfer data, the diagram currently cannot be fully automated and therefore an online tool is currently not available to the public for use on any structure.

The diagram illustrates that for this structure significant water right decrees have been transferred from irrigation to municipal and other uses. Decrees also have been added to allow the structure to be used as an alternate point of diversion. The cumulative result is that over half of the water right amount for the ditch are currently decreed for municipal use.

This is a prototype that has been developed to demonstrate possible functionality. Additional development is needed to enable a general tool that could be used for any structure.