national multiple family submetering and allocation billing program ...

assumptions and it is recognized that changes in some of these assumptions could impact the
results.
One of the central efforts of the research project was to disaggregate each property’s
water use data into seasonal and non-seasonal (outdoor and indoor) use. This process was not
necessary for properties equipped with separate irrigation meters, but it was necessary for the
rest of the properties, and was accomplished by using the established method of average winter
consumption (AWC). However, because many of the properties are located in warm regions,
manager survey results indicated that irrigation occurred 12 months out of the year at some of the
properties. This reduces the accuracy of the indoor/outdoor disaggregation and hence some
outdoor demand may still be include in the indoor use estimates for these properties.
Similarly, at some properties indoor water use for common area such as offices, meeting
rooms, and other facilities may be included in the indoor per unit calculation. However, the
manager survey sought information on some of these potential common area water uses and
every effort was made to correct for these uses during the statistical modeling effort.
Exhaustive effort was made to select study sites that were geographically balanced,
however, the 13 study sites that participated in this project are weighted towards the West and
Southwest regions of the U.S. Many of these study sites have a historic interest in demand
planning and management and have instituted water conservation programs, which often include
public information campaigns. These factors should be considered as possible behavioral
influences, and might cause these results to differ from a national response.
The concentration of impact properties at each study site also varied considerably. For
example, in the postcard survey, Austin had 233 RUBS properties, while Hillsborough County
only had 3 RUBS properties. This could cause results to be weighted towards the areas of
greater concentration.
Finally, this research study relied heavily on survey data. Even with a careful design,
survey questions can be subject to interpretation. For example, by comparing the written survey
responses with the actual site visits, it was found that there is some confusion among property
managers in distinguishing between total-capture and partial-capture submetering. We have
attempted to acknowledge discrepancies like this where applicable, and they are noted in the text.
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