ESTIMATION OF POTENTIAL FOR MANAGEMENT-BASED PRACTICES TOMEET IID ON-FARM WATER CONSERVATION GOALS

摘要

The Imperial Irrigation District of Southern California (IID) is embarking on anambitious program to conserve 303,000 acre-feet per year for transfer to other ColoradoRiver water users in California. Conservation will be achieved through a combination ofsystem and on-farm improvements. On-farm conservation of approximately 200,000acre-feet of water per year will be achieved through a voluntary program in whichparticipants have the option to choose which conservation measures to implement onindividual fields based on incentive offerings.In 2007, IID completed the Efficiency Conservation Definite Plan (Definite Plan), whichidentifies likely components of the on-farm program, including expected on-farmconservation measure implementation by participants for varying incentive offerings.Expected increases in irrigation performance, reductions in farm deliveries, andcorresponding implementation costs were estimated for each field for each season andcompatible conservation measure.Estimation of delivery changes was accomplished by modeling performance increases asa function of the crop, soil, and irrigation method at the field; the conservation measureselected; and the historical irrigation performance of the field. The model wasdeveloped, in part, based on simulations of surface irrigation performance across a rangeof inflow rates and cutoff times for historical irrigation events monitored by IID.This paper provides a brief background and overview of the on-farm component of theEfficiency Conservation Definite Plan, describes the evaluation of management-basedconservation measures such as irrigation scheduling, and compares conservationestimates for management-based conservation measures to other conservation measuresevaluated as part of the Definite Plan.