Hi, unfortunately you cannot tell what the GPM are going to be on a well based on it's depth. It's depth just tells you how far down you had to go to reach the water supply. They have to do a draw down test or other meathod to determine it's GPM it's capable of. If you have a particular property in mind and it doesn't already have a well to test it's GPM, what I would recommend is if their is a nearby neighbor that has a well you could see what depth and GPM their property produces, this "may" be indicator of what yours might do. Also, I would check the Spokane County website for well log reports that they may have on adjacent property, this can help give you a possible idea as well. I good referal Company for well drilling and questions that I give my clients is B&B Drilling, ph# 1-888-276-2874. I hope this is useful info for you and take care! Most Sincerely, Chris Warmuth Windermere/North Spokane, WA.

Gallons per minute, well depth and pump capacity don't have a mathematical correlation. There's a lot of factors that play into the available volume of water that you can draw from a well. Talk to a local well driller and they'll be a wealth of information. For normal household use you can get by nicely on 30 gpm. If you're running an irrigation system you may need twice that.