Rainwater Harvesting and

Water Conservation

Water in Phoenix

• Between July 2005 and June 2006, Phoenix residents consumed about 109 billion gallons of water

• Phoenix water is provided to more than 1.4 million residents

• The total water service area for Phoenix is about 540 square miles

• Between July 2005 and June 2006, the demand for water ranged 429 million gallons per day during the summer

season to 188 million gallons per day during winter season• Phoenix residents consumed approximately 170 gallons

each day at home• About 95 percent of the water consumed by Phoenix

comes from surface water sources

Source: http://phoenix.gov/WATER/wtrfacts.html

Valley Rain Precipitation

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The Phoenix valley gets over 8 inches of rain which represent a significant opportunity for rainwater harvesting and water conservation.

Our team designed a rainwater harvesting system for the Guadalupe residence.

1. With over 8 inches of potential rainwater, buildings in the valley can dramatically reduce their water consumption by using rainwater:

Water calculation=[(Catchment area of building x inches of rain x 600 gallons)/1000]75%(efficiency loss)WC=[[1550 X 8.4 X600]/1000]75%

Total: 5,859 gallons of water

2. Grey water system:According to our calculations we can divert up to 150 gallons per day into the courtyard. This water will be diverted from thesink and shower in the master bedroom bath.

3. Integrate highly efficient fixtures.

1. 5,859 gallons of rainwater

350 gallon tanks

Gutter to collect rainwater

Water will collect from four roof points. This water will drop into the gutter and

then into the five 350-gallon storage tanks.

Five 350-gallon storage tanks were installed on the back of the guest casita. These tanks will store all rainwater for future use of gardening

and other outdoor needs.

Leach system to court yard

This simple grey water/leach system will divert almost 100 gallons of water from the master bathroom sink and shower into the courtyard. This water will provide constant moisture to all trees located along the central court.

Trees

The grey water system consisted of a very simple and low tech design provided

by the University of Arizona’s Environmental Research Laboratory. All

grey water coming from the master bathroom’s shower and sink are diverted

into the courtyard.

The system includes a trap to collect hair and other solids that could block the irrigation holes in the piping. In order to avoid roots breaking into the pipe, the pipe is wrapped in

weed control synthetic fabric and then covered with dirt.

The Guadalupe House also saves water with the following devices: dual or low-flow toilets, tankless water heater, and faucet and shower aerators.

Tankless water heaters provide hot water only as needed. The heater functions as a radiator in which water is being heated only when a faucet or shower is being used. Traditional heaters have a tank where water is hot at all times whether or not it is needed. This represents a tremendous waste of resources.

Faucet and shower aerators are very inexpensive, easy to install and can save homeowners an average of 30% of the water consumption.

A 1.6/0.8 gpf dual flush toilet featuring unique two button activation providing substantial water savings compared to standard toilets and adjustable rough in and smooth rounded contours for easy cleaning. The tank incorporates the Duo-Flo mechanism which has been developed to ensure optimum flushing performance. Due to the substantial water saving achieved by the dual flush system this toilet is highly recommended where water conservation is important.

All of these trees will be irrigated by grey water.

Water conservation through re-use and harvesting is extremely

important in fragile ecosystems and arid environments. Arizona faces a

challenging future if water is not managed adequately and conservation strategies are not implemented. Water

conservation at home can make a significant impact to lower the overall

regional water consumption.