<i>the average rainfall is likely close to 0 inches in LA of which almost none is usable for landscape purposes</i><p>The average rainfall is Los Angeles is 15 inches per year.  Why do you say this is &quot;close to 0&quot;?<p><i>I would not be surprised if this much water is needed for a 2 acre or smaller sized lawn.</i><p>1300 gallons&#x2F;hour * 24 hours * 365 days&#x2F;year = 35 acre feet &#x2F; year.<p><a href="https:&#x2F;&#x2F;www.google.com&#x2F;search?&amp;q=1300+*+24+*+365+gallons+in+acre+feet" rel="nofollow">https:&#x2F;&#x2F;www.google.com&#x2F;search?&amp;q=1300+*+24+*+365+gallons+in+...</a><p><i>I</i> would be surprised if someone was putting 15 feet of water per year on a lawn!  For comparison, the average Southern California golf courses about 3 acre-feet per year: <a href="http:&#x2F;&#x2F;www.kcet.org&#x2F;news&#x2F;redefine&#x2F;rewater&#x2F;drought&#x2F;drought-fact-check-teed-off-about-golf-courses.html" rel="nofollow">http:&#x2F;&#x2F;www.kcet.org&#x2F;news&#x2F;redefine&#x2F;rewater&#x2F;drought&#x2F;drought-fa...</a>