Rainwater Harvesting for Drylands, Volume 3 describes a simple gravity-fed drip irrigation system hooked up to an above-ground cistern. The suppliers for some of the parts are listed below:

Drip irrigation emitters for low-pressure gravity-fed systems

Rain Bird 2 gallon/hour Xeribug emitters and 4 gallon/hour flag-type emitters work well with gravity-fed drip irrigation systems.
In Tucson, AZ
• Irrigation & Sprinkler Supply, Inc. (ISS)
2130 E. 12
792-4652

Low tech/low cost irrigation timer that works with low-pressure gravity-fed systems:

• Toro® Battery Operated Hose-End Timer (Model 53746)
This timer can be set to a watering frequency ranging from every hour to once a week. Watering durations can be set from 1 to 120 minutes. It requires two AA alkaline batteries, although models are available that can be connected directly to an electrical line. It is placed between the tank’s faucet and the hose or drip irrigation line. Available at larger hardware stores. Cost $30.

Unglazed clay pots for clay pot irrigation

Look up “Pottery” in your yellow pages, and ask for the discounted chipped pottery since you will be burying it.

• Agua de Vida They make ollas specially for subsurface clay pot irrigation.
www.ollas.eastcentralministries.org
In Tucson, Arizona
• Mexican Garden Pottery
2901 N. Oracle Road
624-4772