AWWA SOURCES66607

This paper describes experiences and new learning from working with end use models todetermine the loss in effectiveness of drought water reduction measures caused by theimplementation of long-term conservation programs. The goal of the paper is to show how modeling water use and customer behavior at the end uselevel enables a realistic assessment of just how much cut-backs in demand can be expected andhow those cut-backs are reduced due to the efficiency improvements obtained through long-termdemand reduction programs.The paper will provide the following types of information, drawn from completed projects:1. How to model a drought cut-back ordinance as a short-term conservation measure.2. Which end uses can still be reduced in a drought3. How short-term and long-term end use reductions interact4. Typical magnitudes of demand hardening as a function of the amount of long-termconservation implemented or planned.5. Realistic expectations for customer cut-backs in droughts in say 2025, afteraggressive long-term conservation programs have been implemented. The Least Cost Planning Demand Management Decision Support System, or DSS model, an enduse cost-benefit tool, has been used for 150 projects over the past nine years. Only recently hasit been used to model demand hardening. Findings to-date are showing that drought ordinancesthat call for a 25 percent short-term demand reduction might only achieve 21-22 percent cutbacksif the plumbing and appliance codes and long-term programs together will save about 15percent. That is, the demand hardening is only a few percent in this situation. However,expectations of achieving temporary 35 percent cut-backs, as in the past, are not realistic. Theuse of an end use model will reduce the amount of guess work currently required in drought andsupply planning, and reduce one impediment to funding long-term water conservation programs. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

02/01/2008

Number of Pages:

37

File Size:

1 file , 760 KB