FLOOD02879 - Laserfiche WebLink

Home Browse Search

Alternatives should also include the concept of more efficient management of existing supplies of irrigation water. 3.2.4 Identification of Plan Elements The plan elements are the building blocks which are used individually or in combinations to develop planning alternatives; they may be structural or non-structural. Structural plan elements would include, for example, water storage and conveyance facilities. Non-structural plan elements would include measures for reducing demands or increasing supplies by means which do not require substantial structural. improvements. Some examples of non-structural plan elements are water rights exchanges, new or revised institutional arrangements, pricing policies, and conservation programs. 3.2.5 Preliminary Evaluation of Plan Elements After a broad range of plan elements has been identified, they should be evaluated in a preliminary fashion to determine which elements appear to be most useful for plan formulation. The evaluation might include capacities, locations, geotechnical characteristics, yields, costs, and impacts. This is generally a very preliminary analysis based mainly on professional judgment. 3.2.6 Formulation of Preliminary Alternatives Some or all of the plan elements which have been evaluated in the previous task can now be used to formulate a number of alternative plans. Plan formulation is generally a trial-and-error process in which various combinations of plan elements are formulated and tested for effectiveness in meeting the study objective(s). One commonly used method for testing alternatives is an algorithm or model of the system being studied. The model can be used to perform a series of operation studies to evaluate the demands and yields which result from each combination of plan elements. Prior to the formulation of alternatives, a strategy or rationale for plan formulation should be developed. The strategy provides a framework for the formulation process. Example: A city plans to augment existing water supplies to provide for future development. Assume that the city will consider independent sources of supply as well as obtaining water from a nearby city. In this case, the fonuulation strategy could be described in terms of three sets of alternatives as follows: (1) Alternatives for a completely independent system, (2) Alternatives for obtaining the needed supply from the nearby supplier and (3) Alternatives that include both independent and dependent plan elements. 17