Diversion-Runoff Calculator User Manual

Both geospatial and timeseries data are required within the Diversion-Runoff Calculator.  The required data are listed below:

The Water Related Land Use dataset (https://gis.utah.gov/data/planning/water-related-land/) provides information related to crop types and irrigation practices for the State of Utah. The dataset is updated annually and comes in Shapefile format. Approximately 76 different combinations of crop type and irrigation method from the Division of Water Resources (DWRe). The shapefile is converted to a raster for certain calculations within the DRC. Both formats are utilized by the calculator.

The datasets discussed below are available from https://utahdnr.maps.arcgis.com/home/search.html?q=NetFields&start=1&num=20.

NetFields.shp is a polygon shapefile that indicates lands that are irrigated within the State of Utah.  The NodeID attribute is used to connect each irrigated area to a specific canal and water right (discussed below).  The shapefile is converted to a raster with each cell being the NodeID value.  The raster is named NetFields_NodeID_Raster.tif.

NetFlowlines.shp is a polyline that represents the canals, streams, rivers, and pipes that convey water within the State of Utah.  The FlowlineName and RecordID attributes are used within the DRC.  The NetFlowlines.shp is an exception where the file does not have to be in the EPSG: 4269 projection.

NetPathPoints Table_TableToExcel.xlsx connects the NodeID to one or more PathID’s.   In the table it is imperative that the NodeID is in column 3.

NetPathLines Table_TableToExcel.xlsx connects each PathID to a FlowLine.  In the table it is imperative that the PathID is in column 2.

NetPaths Table_TableToExcel.xlsx connects the PathID to Water Rights.  It is imperative that the PathID is in column 1.  It is assumed that the PathID in this table is the same as the RecordID (from NetFlowlines.shp).

Flow data is not used to calculate diversions or runoff. Instead, the flow data is used at the canals to compare observed canal flow rates against what the DRC would expect the canal would need to take from the river based on crops, irrigation methods, and efficiencies.

Flow data is available from the DWRi website: https://waterrights.utah.gov/distinfo/distribution_systems.asp. The flow data is stored in “CanalFlow_DWRi/data” folder.

Flow data need to be matched with the appropriate diversion in order for the observed data to appear in DRC generated plots as well as in the combined output (‘CombinedDiversionDepletion.xlsx’). This indexing happens through the ‘Observed_List.csv’. In this file, the appropriate filename for each set of observed flow is paired with its respective flowline name.

Net Irrigation Water Requirement (NIWR) estimates for various crops at multiple weather stations throughout the area of interest are obtained from (Hill, 1994) (example below). The data for each weather station is stored in text format (e.g. UT_Table_Hanna.csv) in the “ET_Tables” folder. For a given field the closest weather station evaluated by Hill (1994) is used to determine the monthly consumptive use.

Additional station information (i.e. Lat/Lon, Elev, etc.) is provided in the ‘UT_Table_ConsumptiveUse.xlsx’ file. This information is needed by the DRC to identify the nearest stations.

The Depletion-Runoff Calculator (DRC) estimates crop water demand using field-scale evapotranspiration (ET) data derived from remote sensing. Historically, the DRC utilized actual ET estimates from OpenET (Melton et al., 2021), which provided satellite-based ET and precipitation time series data through a shapefile containing unique OpenET identifiers (OpenETID). These datasets were generated using the eeMETRIC model—a Google Earth Engine implementation of the Mapping EvapoTranspiration at High Resolution with Internalized Calibration (METRIC) approach. Access to OpenET data requires registration through OpenET and retrieval via the Google Earth Engine platform.

However, the DRC now primarily relies on the ET Demands dataset developed by the Bureau of Reclamation, in collaboration with the Desert Research Institute and the University of Idaho. ET Demands is a state-of-the-science, open-source evapotranspiration modeling tool that estimates actual crop evapotranspiration (ETa). It uses the dual crop coefficient method outlined in FAO-56, incorporating daily weather data, crop-specific growth curves, and a daily soil water balance model that accounts for effective precipitation (Pe) and carryover soil moisture.

Compared to standard OpenET outputs, ET Demands offers enhanced capabilities by integrating detailed soil moisture accounting and more accurate representations of crop water use under varying climatic conditions. While point-based ET Demands data is publicly available for download, spatially distributed datasets must be requested directly from the Bureau of Reclamation.

In the current implementation of the DRC, both OpenET and ET Demands data have been evaluated, but ET Demands is now the primary input source due to its higher precision and compatibility with decision support tools. All relevant ET Demands data used in the model are stored in the ET_DEMANDS layer and corresponding CSV files, replacing the prior OpenET-based pipeline.

ESRI Geodatabase Feature Layers 

Alternatively, the DRC can read-in feature layers from an ESRI file geodatabase in lieu of rasters and shapefiles if ArcPy is available (see ‘Using an Existing ArcGIS Conda Environment'). For this method, all the feature layers need to be in a single geodatabase. In this case, the user specifies the geodatabase (e.g., 'UCRAF_DiversionCalculator.gdb') containing the following feature layers:

A python utility called ‘CreateGeodatabase.py’ is available to create a geodatabase with feature layers derived from the shapefile and raster datasets identified above (ArcPy is required).