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Section 6 Water Needs Assessment never be approved for construction of projects or that mitigation requirements may make a project cost- prohibitive or fail to produce the planned yield. Some providers are pursuing multiple projects simultaneously to account for this risk, while others will need each of their ldentified Projects and Processes to meet future demands. Uncertainty associated with the Identified Projects and Processes is discussed in Section 6.2. A conceptual overview of the M&I gap analysis method is provided in Figure 6-1. In hypothetical Subbasin A, the entire increase in demand can be met by that subbasin's Identified Projects and Processes and existing supplies - meaning there is no remaining gap if all the Identified Projects and Processes are successfully implemented. In contrast, in hypothetical Subbasin B, the Identified Projects and Processes and existing supplies can only address a portion of the increase in M&I demands, so the remaining gap will need to be addressed by Options for Alternatives. Increase Increase in - in Demand - - Demand sug- BASIN A sug- BASIN B Alternatives needed to meet remaining gap Figure 6-1 Example of Preliminary Gap Analysis 6.1.2.2 Agriculture The needs for agricultural uses were evaluated through the use of DSS in the Colorado, Dolores/San Juan/San Miguel, Gunnison, Rio Grande, and Yampa/White/Green Basins. The DSS data were supplemented with feedback during the Basin Roundtable process and discussions with the Division Engineers. The Arkansas, North Platte, and South Platte Basins do not yet have a DSS, and evaluation of agricultural needs was determined by feedback during the Basin Roundtable process and discussions with the Division Engineers and water users in the basin. r~ The reader is encouraged to review Section 5 to more fully understand the approach and methodology used to identify agricultural shortages. Many agricultural water systems in Colorado have evolved to be productive with less than an ideal water supply (see Irrigation Water Requirement). A crop does not have to have water at all phases of its growth in the maximum theoretical amounts. In other words, some shortage can be tolerated and still yield economically acceptable return on investment. Finally, it should be noted that some agricultural water systems are capable of delivering adequate water to satisfy crop requirements, but still can operate at less than 100 percent water allocation. For agricultural demands, water districts with current shortages of 10 percent or greater were identified in Section 5. Without solutions to address these shortages, it can be expected that these shortages will continue on through 2030. Figure 5-10 indicates the water districts on the West Slope and Rio Grande where agricultural shortages average greater than 10 percent. Agricultural water shortages are widespread in the South Platte and Arkansas Basins. In the South Platte Basin, shortages are expected to increase as municipal providers become more efficient and increase reuse of return flows that previously were unused and available for use by downstream agricultural users. In the South Platte Basin, the increased use of M&I return flows, together with the well augmentation requirements of Senate Bill 73, are projected to result in increased agricultural shortages and a decrease in irrigated acres. In addition, the continued transfer of CBT units from agricultural to M&I use will reduce agricultural water availability as this supplemental water supply will no longer be available to address agricultural shortages. As indicated in Figure 5-10, a large majority of the state is estimated to have significant agricultural shortages, whereas the Colorado and Yampa/White/Green Basins will have relatively fewer water districts without average annual agricultural water shortages. All basins expressed a need to firm up existing agricultural supplies regardless of changes in irrigated agricultural acreage. However, in many basins agricultural users indicated that acquiring additional water or implementing new or enlarged storage was not economically or technically (due to lack of water 6-4 S:\REPORIIWORD PROCESSING\REPORllS6 11-8-04.DOC