GPM Flow Question

We just had a new well drilled at a new home we are building. It is 330 feet deep, with 145 feet of casing. The driller informed us that there is a flow rate of 4gpm. He told us he drilled down another 20 feet past the point where he hit water to allow for a 'pocket', or reservoir of water so I won't run dry. My question is, is a 4gpm flow rate sufficient for a home with 2 adults living in it, or am I going to have problems in the future? Any opinions are appreciated. Thanks.

It all depends on how much water you use.

I would like to have at least 10 times that for my normal usage around the house, not counting the Tree Farm which has another pump. But 4 gpm may be enough for you. If not, a Cistern may be in order.

bob...

Hmmm...isit possible to increase the flow if it proves to be not enough?....Like by hydrofracturing? Or am I stuck with the flow we have? By cistern, do you mean a holding tank in the basement? Thanks again!

Hydrofracting may help. I've never done it or had it done in my area as we have all the water we can possibly use here.

A Cistern can be in the Basement or buried in the yard if done right. It just has to be big enough to give you the demand needed for daily usage. It can be refilled as the water is used.

bob...

Thanks Bob...I always enjoy coming to this forum - great info and helpful people!

Gerry

Four GPM x 1440 minutes per day = 5760 gallons per day. That is a lot of water for a household that typically uses 250 to 400 gallons per day.

Whether it is enough for household peak demands depends on how much water is stored in the well and the capacity of the pump. A 4" well contains0.65 gallons per ft and a 6" well contains 1.47 gallons per foot, so if you have 100 ft of standing water in the well above the pump you have 65 or 147 gallons available for pumping, beyond what the well produces.

The other limit is the pump. You can check that by running an outside faucet at a rate that just allows the pump to keep up with the mid-point pressure of your pressure switch setting and measuring the flow rate in gallons per minute using a large bucket.

You should make sure that the pump is sized correctly to be able to use all the usable water in the well and set at that depth. Usually 10-15' off the bottom.