Question
When my house was built, my well for the house only pumps 3.5 gpm.  I was told there was no water elsewhere on the property.  We found a shallow well (in sand) that is 8 feet down, but only about 7 feet deep.  Do you think that would be enough water to support irrigation for a lawn of about 16,000 sq. feet.  If not, is it enough to at least water plant beds, gardens, etc.  When I hooked a pitcher pump to it, we filled a 5 gal. bucket in about 45 seconds.  

Answer
To water the lawn with that would be almost impossible. The beds are possible if you use drip or micro sprays- Depending on the size of the beds. With regular sprinkler heads you would only be able to run 2 rotors with 1.5 gallon nozzles at a time. They would throw about 30 feet, so you would have 20- 30 zones and the sprinklers would have be running 10-15 hours a day. You could try to do something for the beds and if it works better than you thought add on for the lawn later. Jim