Residential Water Conservation Progress Report for Casa Del Agua

Abstract

Casa del Agua, a research and demonstration water conservation house, was opened to the public in September 1985. This typical 3 bedroom residence has been re-landscaped and retrofitted with storage for rainwater and graywater and low water use plumbing fixtures including toilets. A unique graywater treatment system employs two 300 gallon aquacells and a sand filter to upgrade graywater quality. The house is occupied by a family of three and detailed data are being obtained on water input, use and quality. Qualitative measures include microbiological, physical and chemical characteristics of filtered rainwater and treated, untreated and stored graywater. A model of water efficiency for dwelling units known as the "W-Index" is being formulated as a quantitative measure of residential water conservation options. The numerical evaluation of weighting of the index components will be aided by means of data generated in the monitoring program at Casa del Agua. A nomogram has been developed to provide a ready mechanism to determine the necessary storage volume for rainwater in terms of a specified availability of supply, catchment area, and rate of water use.