RGDSS_Historic_CUreport_20040601

• Title: RGDSS - Rio Grande Historic Crop Consumptive Use Analysis
• Description: The documentation is for the Rio Grande Basin Historic Crop Consumptive Use Analysis, developed during the RGDSS implementation for the period 1950 through 2002. It includes 100 percent of the crop consumptive use in the basin for the period. Documentation consists of the final Historic Crop Consumptive Use Analysis Report and supporting appendices.
• Decision Support - Doc Type: Modeling Dataset Documentation
• Date: 6/1/2004
• DSS Category: Consumptive Use
• DSS: Rio Grande
• Basin: Rio Grande
• Contract/PO #: C153863
• Grant Type: Non-Reimbursable
• Bill Number: HB98-1189, SB99-173
• Prepared By: Leonard Rice Engineering

4.3 StateCU Structure File (rg2004.str)
A structure file provides the list of structures to be use in the analysis. The structure file
contains physical information and structure-specific information that does not vary over
time including location information; available soil capacity; and assignments of climate
stations to use in the analysis. Location information includes the latitude, county, and
HUC for each structure. The latitude is used in the Blaney-Griddle method to determine
the hours of daylight during the growing season.
The structure file used in the historic consumptive use analysis was created using
StateDMI to extract diversion structure location information, soil capacity information,
and climate weight assignments stored in HydroBase based on a list of structures to be
used in the analysis. The Surface Water Contractor was responsible for classifying
structures as key, aggregated, and ground water only. As presented in Table 3, 87 percent
of the acreage was assigned to key structures. The approach and results are outlined in the
memoranda prepared by the Surface Water Contractor for Task 6.2 Key Structure
Determination, Task 7.1 A~~re~ated Water Rights/Irrigated Lands Not Explicitly
Modeled, and Task 8.1 Review Well and Lands Served by Ground Water Only.
Table 3
Historic Consum tive Use Structure Scenario

Structure Type
Acres Number of
Structures Percent of
Total Acreage
Key Diversion Structures 541,151 363 87%
A re ated Diversion Structures 23,721 44 4%
Ground Water Only Structures 57,996 62 9%
Total Structures 622,868 469 100%
In general, the following criteria were used in determining whether structures would be
modeled explicitly or in an aggregated fashion:
Key Diversion Structures: Ditch systems, totaling 541,151 acres, with relatively
large diversions, senior water rights, or important in administration of the Rio
Grande were defined as key. In addition, most structures represented in previous
models were defined as key.
A~~re~ated Diversion Structures: Ditch systems, totaling 23,721 acres, not
defined as key diversion structures were grouped together into aggregated
diversion structures. For structures without mapped service areas located outside
the valley floor, acreage was estimated using information reported by water
commissioners. For structures without mapped service areas located inside the
valley floor acreage was not estimated. This is because the irrigated acreage
assessment is believed to be complete for the valley floor and structures without
mapped service areas are estimated to have their acreage included with acreage
from other ditches.
cureport_6-2004.doc 18 of 48 June, 2004