I'm glad to know that the USGBC is trying to promote use of non-potable water sources since my clients are usually more willing to invest money in stormwater detention features. However, we should be careful about making very strict requirements. If the client and the whole team sees that achieving second point for this credit would be very expensive (e.g. Reuse at least 90% of wastewater on site could be) they will maybe decide to omit the water reuse at all because only one point does not create strong incentive enough to balance the added hard costs.