RGDSS_CU_Losses_Summary

• Title: RGDSS - Rio Grande Basin Consumptive Uses and Losses Summary
• Description: The documentation is for the Rio Grande Basin Consumptive Uses and Losses Summary, developed during the RGDSS implementation for the period 1991 through 1995. It includes 100 percent of the consumptive use in the basin for the period.
• Decision Support - Doc Type: Modeling Dataset Documentation
• Date: 11/1/2000
• 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

2.0 Introduction
The estimation of historic consumptive uses and losses in the Rio Grande Basin and the
tool used to perform the analysis are documented in four major reports as follows:
1. The Irrigated Lands Assessment Report describes the development of the 1998
irrigated lands coverage, including the process used to determine irrigated acreage,
associated crop type, irrigation method (sprinkler or flood), and surface water source.
2. The Historic Crop Consumptive Use Analysis Report is the main document
associated with estimating consumptive uses in the Rio Grande Basin. It describes
the approach and results of the agricultural consumptive use estimates.
3. The Consumptive Uses and Losses Summary Report describes the approach and
results used to develop the estimate of total basin water use due to human influence
for 1991 through 1995.
4. The StateCU Documentation describes the consumptive use model and graphical user
interface used to perform all consumptive use analyses conducted as part of the Rio
Grande Decision Support System.
This Consumptive Uses and Losses Summary Report has not attempted to reiterate the
detailed analyses performed in support of the final consumptive uses and losses analysis
and described in the other major reports. Instead, it summarizes the major results and
includes the technical memorandum on other (non-agricultural) uses in Appendix A.
2.1 Basin Description
The Rio Grande Basin (Figure 2) is located in south-central Colorado and encompasses
approximately 7,500 square miles. The valley floor (San Luis Valley) elevation ranges
from 7,440 feet in the south to 8,000 feet in the north and is bounded on the west by the
San Juan Mountains and on the east by the Sangre de Cristo Mountains. There is an
approximate 3,000 square mile area in the northern part of the valley that does not drain
to the Rio Grande because it is separated by a low divide in the shallow ground water
table. This non-tributary area is known as the Closed Basin.
RGDSScusumm.doc 3 of 11 November, 2000