CRDSS_Task1_14-14_EnhancementstoBlaneyCriddleforCRDSS

• Title: CRDSS Task 1.14-14 - Consumptive Use Model - Enhancements to the Soil Conservation Service Blaney-Criddle for Use in the CRDSS
• Description: This document describes Soil Conservation Service ‎(SCS)‎ Blaney-Criddle ‎(XCONS2)‎ and presents the enhancements that are part of the consumptive use ‎(CU)‎ model.
• Decision Support - Doc Type: Task Memorandum
• Date: 1/9/1995
• DSS Category: Consumptive Use
• DSS: Colorado River
• Basin: Colorado Mainstem
• Contract/PO #: C153658, C153727, C153752
• Grant Type: Non-Reimbursable
• Bill Number: SB92-87, HB93-1273, SB94-029, HB95-1155, SB96-153, HB97-008
• Prepared By: Riverside Technology inc.

Input for water supply from irrigation structure and diversion records will be monthly, where available.
If the supply is less than the expected demand for a given month, a percentage of pasture grass and
alfalfa acreage will be changed to alfalfa-short and pasture-short for the month. Alfalfa and pasture-
short crops are assumed to have no consumptive use for the month they are short. If the next month?s
supply is sufficient to meet expected demand, the normal consumptive use characteristics will be
assumed.
3.0 CONCLUSIONS AND RECOMMENDATIONS
The current implementation of the Enhanced SCS Blaney-Criddle CRDSS CU method will maximize the
beneficial contribution of stored soil moisture from effective precipitation and winter buildup. The main
features are a monthly soil moisture budget, inclusion of water supply, and the ability to consider
effective precipitation buildup in the soil profile.
In addition to these enhancements, procedures are being added for calculating consumptive use for
agriculture categories, such as stock pond evaporation and livestock uses, as well as ?other categories.?
Other categories include municipal, industrial, reservoir evaporation, and basin exports. In the past, the
consumptive use calculations for these categories were not automated. Also, the CRDSS CU model will
include a calibration factor to increase the accuracy of the model for local conditions.
The enhancements of the XCONS2 methodology for the CRDSS CU model should be implemented and
will improve the accuracy and usability of the SCS Blaney-Criddle methodology and the USBR
methodology for preparing consumptive uses and losses reports for the Colorado River system.
4.0 REFERENCES
Blaney, H.F., L.R. Rich, W.D. Criddle, et al. (1952). ?Consumptive use of water.? Trans. ASCE ,
117:948-967.
Jensen, M.E., R.D. Burman, and R.G. Allen. (1990). ?Evapotranspiration and Irrigation Water
Requirements.? ASCE Manuals and Reports on Engineering Practice No. 70. American Society
of Civil Engineers, New York, New York.
U.S. Bureau of Reclamation. (1986). Colorado River Systems Consumptive Uses and Losses Report,
1981-1985. Technical Appendix Volume 1.
U.S. Department of Agriculture, Soil Conservation Service. (1970). ?Irrigation water requirements.?
Tech Release No. 21, (rev.) 92 pp.
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A275 01.09.95 1.14-14 CSU IDS