100% irrigation requirement met through treated waste water

I find the credit language very confusing. Specially because there seems to be a repetition of captured rainwater and recycled wastewater in both options! Do I need to carry out the calculations if I can can demonstrate that the quantity of treated waste water available for irrigation is way more that the total landscape irrigation requirement all throughout the year? We have over 50000 LPD of non-potable water available for a softscape area of only 1500 SqFt. I do not see what the point of doing the calculation is if the credit allows me to show waste water reuse as acceptable strategy for option 1: 50% total water reduction and also option 2, Path 1: 100% non-potable water use. So essentially I can get 4 points simply for using non-potable water even if my entire softscape is turf. Also, is there a way I can get a sample calculator in excel? We are registered to be certified through LEED India and do not have access to any of the fancy online portals/forms. Over 80% of our project time has been spent in creating so many calculators in excel from scratch.