Laserfiche WebLink
<br />" - <br /> -- <br />I <br />3.1 Weather <br />In water usc fQre~ting. it is typiqaJ to "weather normalize~' base year water use. Water <br />use tends to increase With hot, dry weather and cJeç~e with cøol, wet weatha-. Hence, it <br />is importantt ) adjust forabnonnaJ weatberpattCITIS mo. to estâblfsb an unbiased <br />startìng point for the forecasts. <br />We co1leçted monthly rain and daily maximum temperature data fwm the NationaJ <br />Atmospheric and Oceanic Administration for the Redwood City weather station over the <br />period 1948 to date. Our analysis oflhis data shows that weather during the calcndar year <br />2000 was closer to normal than any other year in the series, This simplifies the weather <br />normalization task as the 2000 water use data are already effectively weather nonnalized. <br />The annuaJ weather values for :WOO and oormal are shown in Exhibit 4. <br /> Exhibit 4. Weather for Year. 2000 <br /> Descrlntloll 2000 Norm:al <br /> Annual Rain (inches) 1957 20.21 <br /> Annual Average of Daily Max <br /> TcmoeratUre ¡OF) 71.0 71.3 <br />3.2 Water Prices <br />Changes in water prices are also knGwn to change customers' behavioral decisions <br />regarding wateruge. Following the first law in economic demand theory, as the real price <br />ola commodity increases, the quantity demanded by consumers decreases. <br />A review of R we water prices sllows they have remained relatively stable over recent <br />years after adjusting for inflation. Thi.s findins; of rate stahilityagain simplifies the <br />anaJysis8S there ¡sno need to make water price adjustments to base year water use. <br />Appendix E contains thð 2002 wmer price SChedu1ð. <br />3.3 Water Conservation Technolol!Îes <br />Watcr fixtureS gave tended to become more water efficient over time because of <br />ìmprovements in water conservation tecbnologies. In this study, we specifiçalJy aCCO1l!lt <br />for known water using efficiencies occurring with toiletS and clothes wasbers. These are <br />the tWo largest end.uscs of indoor residentil11 water use. malc.ing up about half of total use. <br />Toilet manufaçtures<:ame Gut with 1.6 gallon per flush tOílðts~ known as ultra-low flush <br />toilets or ULPTs, in 1989. Toilets before this time used 3.$ gallon per flush or m.ôre, In <br />January 1992, a CalifGmial'lumbing Codecbånge requíredall new toiletS to be ULFrs. <br />Manyoldet, less-efficient toilðts were S!Íll beIng sold, however, at this time. A Fedentl <br />plumbing code cbange effective January 1994 mandated ULFTs be used in all new <br /> Page 5 <br />