New well, 10gpm enough?

[megotatractor]

Hi, opinions/experience wanted.

Does anyone have a 10 gallon/minute well that is inadequate to their needs, and when does it fall short?

We drilled a new 4" well with the intention of installing a 10 gpm pump. The well came up shallower (and less expensive) than expected with a 20gpm potential. I work for a wholesaler that only stocks 10gpm pumps and I get a nice price, but I'm wondering if for certain 10gpm is going to be enough if I'm watering the garden or filling a 400 gallon hot tub? Should I consider ordering a higher capacity pump, or is 10 gpm enough?
This new well is replacing an old 2" well with a 3gpm antique stroker pump.
I have "experts" by the dozens to talk to but want experiences from real well users.
For example would possibly be doing laundry, watering the garden, taking a shower, flushing a toilet at the same time. No, I have no idea the GPM of a simple garden sprinkler. I probably get about 5 to 6 gpm out of the end of the garden hose when filling the hot tub but that isn't done more than every few months.
thanks

 

[MikeInEburg]

Flow rate is a function of total head (combo of height, pipe size and friction-causing fittings) and pressure. If you want higher flow, you'll need to address all of these. The generic answer is that, yes, 10GPM is adequate for standard residential needs. How fast do you need to fill the tub and how many irrigation devices do you need to run at the same time?

Mike

 

[megotatractor]

No need to get technical, we know how to size the pump for the desired output. Just looking for people's experiences with 10gpm wells and when and if they ever fall short.

 

[MikeInEburg]

The generic answer is that, yes, 10GPM is adequate for standard residential needs.
Mike

I guess just read this part of my response...

In reading your modified and expanded original post, I'd say that you'll need to decide for yourself if 10GPM is adequate for your needs.

Mike

 

[RobertN]

We had issues for a bit; our well had originally been tested at 14gpm. Neihbors had well issues too. We had to have our pump pulled to repair some wiringing; turns out the pump was in pretty bad shape.

While waiting for repairs, we decided on a 2500 gallon tank with a it's own pump. The pump was replaced first; a newer more efficient pump worked very well, we had more flow than I ever remember from the existing pump(replace 10 years ago).

We could have canceled the tank installation, but went ahead with it. Now we have 2500 gallons on reserve. If our well does drop in production, it just takes longer to fill the tank. I know people with reliable 2GPM wells. And big tanks.

The other thing is, I now can fill the fire engine I volunteer on 5 times from our tank. It has a 500 gallon tank. The primary staffed engine from our station, and many of the other local engines, has an 800 gallon tank. I can fill those 3 times in an emergency. Closest hydrant is 1/4 mile away; if something happened here, we'd have to bring in Tenders and shuttle water.

FWIW, if you have a 3/4 or 1" residentail line coming to your house, you're only getting around 10gpm

 

[chh]

I am on a well that has a 3 gpm recovery rate. It will run dry if we run the water in the garden too long. I use a pump that is rated for 12 gpm(as best I remember), it makes more than enough flow for the house and anything we want to do. The tank idea is a good one and I would probably have one if we needed to use enough water that it caused a regular problem.

 

[J_J]

If you ever need to run a four zone sprinkler system, I think you will need a larger pump. Some of the rotating heads put out 2 to 3 GPM. Design for the future.

 

[RobertN]

Some of the rotating heads put out 2 to 3 GPM. Design for the future.

Most use a lot more than that. A lot of 12' and 15' radius spray heads use that much.

 

[CurlyDave]

Our well tested at just under 10 gpm, and we have never had a shortage of water.

But, we do not irrigate anything.

There is another way to look at this. Our septic system rates for a 4 BR house and is capable of handling 400 gallons per day. That is a little less than 0.3 gpm, which is what I take to be "household usage" for a family of 4 or 5.

Essentially, your flow rate will be determined by irrigation.

 

[laen64]

What would anyone consider needed to irrigate a 4 zone sprinkler system, 5Bedroom home with laundry and the normal usage? I like the idea of the tank system mentioned earlier? Please do give reccommendations as well as possible cost. Thanks in advance.

Especially Pump rating, and motor size!

 

[dmccarty]

We are on a 15 GPM well. From talking to people on wells in my area 5 GPM is more "normal". Most of the neighbors are getting around 5 GPM except one who is over 30 GPM!

Irrigating a garden or zone depends on too many factors to give even a ball park water usage or cost. What kind of heads are being used? Is it drip irrigation? Soaker hoses? How much space is being watered? How many plants? Are the water hungry plants or a desert dweller?

Our garden has three long rows about 36 feet long and three short rows 12 feet long. We use soaker hoses to irrigate. I have a valve system setup to so I can turn on/off each of the soaker hoses. What worked well last season was to run three hoses at a time for about 20-30 minutes. If the garden needed water I would try to water half the garden in the evening and the next evening I would water the other half. But I have also watered the whole garden over an hour with each "zone" getting 30 minutes.

Never had a problem with the well even with the bad droughts we have had over the last few years.

Best I can tell we have a 5 or maybe a 10 GPM pump. Given the well is at 15 GPM we should be ok unless we abuse the well. I figure the well holds 250ish gallons which is 25/50 minutes of water with a 5/10 GPM pump.

Abuse is just running the well too long for the amount of water in the pipe and recovery rate. We were at a friends house and their neighbor came over and said they were out of water! The neighbor had a visiter who ran the sprinkler on the new lawn for hours......

Later,
Dan

 

[J_J]

To check your 5 GPM's. take a 5 gal bucket and see if it will fill in one minute. or, take 5 to 10, one gal jugs and see how many you can fill in 1 minute, the total gal is your GPM on your pump.

If you can fill 2, 5 gal buckets in 1 minute, the you have 10 GPM pump

 

[RobertN]

What would anyone consider needed to irrigate a 4 zone sprinkler system, 5Bedroom home with laundry and the normal usage? I like the idea of the tank system mentioned earlier? Please do give reccommendations as well as possible cost. Thanks in advance.

Especially Pump rating, and motor size!

I think we had $2500 in to the tank, pump, installation, and well pump.

Too many variable to know what a 4 zone sprinkler system would be. Size and number of heads, flow rate of spray versus rotary nozzles etc.

We have had two houses running from our well. One, 3bed/2bat, 2nd a 1 bed granny flat.

For the most part though, we do not have lawn. We run a lot of drip to numerous garden and flower beds.

The other variable is, you get rain in the summer in Alabama? At least here in California, we have a Mediterranean climate, like Italy. We do not get rain in the summer.

 

[J_J]

RobertN.

If you wanted to put in a four zone sprinkler system, with digital control, doing every thing your self, you could get by for about $1200. Probably less. You normally water early in the morning. Automatically come on at around 4 AM and off by 6 . If you go to HD, that have a sprinkler layout booklet that lets you lay out your property, and send it to Rain Bird, or whoever, and they will complete the plans and send back recommendations . It could be an Orbit booklet also. Might have to mess with permits also.

 

[RobertN]

Thanks. I guess I should have explained more in my previous post. Without measurements, plant types, soil types etc, it is hard to estimate for a 4 zone system, actually any number of zones. The OP did not give enough info.

I designed a number of systems and installed them; wife and I had a little landscape company for a few years. Took hort classes at the local JC; irrigation design is one.

I generally do not like the stuff from HD or Lowes. While it is ok, and some is brand name, it is not the same as the Pro stuff from places like John Deere. I have replaced sooooo many controllers, valves, and sprinkler from the box stores. The Pro version Hunters and Rainbirds, I never had to replace.

My particular favorite in controllers is the Hunter Pro-C. It is the easiest to install, and easiest to program/run that I have seen. Some have 6 or 8 channels, some are configurable to many more(mine at home is 24 drip stations, although we are only using 16 right now).

Spray heads, I like Rainbird all the way. For rotors, I like Hunters first, Rainbird second.

The hardest part of the equation I have found, is wells. It is much easier to design and install for "city" water. Well's have flow limitations. And, for wells, the design should make the well pump run the whole time the water is going; it is bad for the pump to cycle. If the well is nearby the controller, a good controller can also control the well pump too.

One thing I see people do frequently that is a no no too, is mix spray and rotor heads. They put out totally different amounts of water, and are in compatible on the same circuit. Spray should be on a spray circuit, and be regulated for pressure. Rotors should be on their own circuit. And, drip should be on it's own circuits based on shrubs vs trees vs flowers etc.

The other is too high of pressure. Most spray heads only need 15-25psi of pressure. Above that, and they mist instead of spray. The mist does not distribute in the same pattern or amount as when the head sprays.

Rainbird, Hunter, and Orbit will help homeowners designing thier own sprinkler setup. All three have good books that cover designing too. Pipe size, flow rate, sprinkler size and type etc.

RobertN.

If you wanted to put in a four zone sprinkler system, with digital control, doing every thing your self, you could get by for about $1200. Probably less. You normally water early in the morning. Automatically come on at around 4 AM and off by 6 . If you go to HD, that have a sprinkler layout booklet that lets you lay out your property, and send it to Rain Bird, or whoever, and they will complete the plans and send back recommendations . It could be an Orbit booklet also. Might have to mess with permits also.

 

[turbo36]

Our well is capable of 70-90 GPM we put in a 25 GPM constant pressure, variable speed pump. These new pump systems are very nice they will vary the motor RPM to control the pressure so it's like having "city water pressue". I run a 10 zone sprinkler system.

I would put in an oversize pump for your current needs because you never know what you wanrt to do in the future.

 

[The Dougster]

We seem to have gotten away from the original question regarding this thread, which was, "Is 10GPM enough ?"
The answer is, "Yes".... The solution for a weak well is an adequately sized pressure tank. Regardless of someone's comments that it is a bad thing to let the well pump run for a long time, it is even worse to allow it to pump off and on in short bursts.... Generally speaking, it's a good idea to monitor the water level... obtain a static water level and then measure often until the pumping level stabilizes. This will give an idea of pumping level to make certain the water remains above the pump motor preventing burning up the motor... Of course, I am assuming you have a submersible pump... If there is the threat to the pump, it's possible to install a switch that will shut off the pump in a timely manner. Hopefully this has been of some help.

 

[laen64]

Very Good Doug! I really needed that, because I'm building soon in and I need these type questions and answers for my contractor/builder. I was considering taking on the project as owner builder but some of the questions I'm finding here has let me know I need to wait and learn a lil bit more.

 

[RobertN]

You are right

Our well is 14gpm, but our pump originally was 5-7gpm(I think...). We ran two houses from it. Our is three of us in a 4bdrm/2bath, spa, small pond, and lost of drip irrigated garden and flower beds. 2nd house is 1bdrm/1 bath, lots of flower beds with drip, and a small lawn.

We could have maintained a high flow, but they are an expensive pump.

The pressure tank helps a weak well for a small burst. Adding a storage tank with constant pressure pump was really nice for us.

When irrigating, yes, you do want the pump on full time; running the pump is not a problems. Cycling it on and off is what wears them out.

They do have sensor switches for if your well runs low, so you don't burn out the pump.

In my case, it is hard to watch the water level in our well; it is 450' deep, with the pump at 425'

We seem to have gotten away from the original question regarding this thread, which was, "Is 10GPM enough ?"

 

[J_J]

While 10 GPM might satisfy you and all the houses, I think that if everyone was using the water for normal use, laundry, dishwasher, shower, etc. Your capacity will diminish for things to work well, such as slow shower slow tub fill, etc. If you space out those activities, you might away with that amount. You could also do irrigation because that is normally done in the early morning. More is better and does come at a price. Is this all you will need in the future? If you get a larger pump, the initial expense will be high, but you might save on the electrical bill in the long run. You are simply pumping more water in less time.