How Do Water Wells Work?

Written by Andy Stauffer

July 24

Introduction: About 75% of the homes we build use a well to supply their water. For this guest post, we’ve asked our well drilling contractor for information about how wells work, what their associated costs are, and how the process of drilling for water and maintaining a well might affect a homeowner we’re building for. We hope you find this information helpful! – Ron Stauffer

Question: When a homeowner is buying land to build a home on, what should they do if they need a well?

Answer: If you’re considering a lot to build on, you should call a well driller before you buy the land, and give them the address and legal description. If you do this, the driller can look up the lot on a map and see which aquifers you have access to. I do this for people all the time: I can pull up aerial photographs that will show me every well within a certain number of miles around, and I’ll look at the ones closest to where your lot is. Based on your aquifer, and what your neighbors have, I’ll know whether you’ll be able to have only “inside water” (just water to supply the inside of your home), or enough to have outside water that you can use for irrigation, etc. We can also make an educated guess on how deep we’ll have to drill and what the ground conditions will be like. It’s not a guarantee, but it’s usually very close; you’ll often have conditions similar to what your neighbors have.

Question: How much does a well cost, generally speaking?

Answer: Obviously that number depends on several factors, but generally, in the Front Range of Colorado, if you’re drilling into the Dawson aquifer and you’re staying under 500 feet, you can plan on spending about $15,000. If you’re drilling into the Denver, Arapahoe or Laramie-Fox Hills aquifers, you can plan on spending $15,000-30,000 or even up to $50,000 depending on the area you’re in and a few other factors.

Your total cost will depend on three basic variables:

  1. What area you’re located in.
  2. How deep we have to drill.
  3. Which drilling machine we have to use.

Our company has three rigs: a small in/out rig, a bigger one, and a “monster” rig; the bigger the rig you need, the higher the cost. If you’re lucky enough to just need a small air driller and the drilling is super easy, it might only cost $7,000-8,000. But my advice to people is to find a well driller they trust, and give them the exact address and legal description of the lot so they can give them a true idea of the cost.

Question: Do I need a permit before drilling a well? If so, who issues them and what do they cost?

Answer: In Colorado, well permits are issued by the Colorado Division of Water Resources. To apply for a permit, you fill out an application, prove your ownership of the land by sending in a copy of the deed, then pay a fee (somewhere between $100-$500 or so) and hopefully in six weeks your permit is approved and you’re ready to go.

Permits often have stipulations on them, called “conditions of approval,” that look something like this:

  1. You must drill within 200 feet of the exact area you specify on the application.
  2. You cannot use more than 15 gallons per minute.
  3. You can only drill into the aquifer specified on the application, at the specified depth.
  4. You must install plain and grouted out casing between certain intervals.
  5. The irrigated area shall not exceed more than a specified acreage of lawn and garden.
  6. The annual withdrawal of water from the well shall not exceed a specified number of acre-feet.

Those are the common stipulations, but occasionally, they’ll even require that you run a geophysical log with a video camera you put down into the well. Colorado is very serious about water usage: they can even require you to install a meter, and send in a report each year of how much water you’ve actually used.

Question: Where is water stored in the ground, anyway?

Answer: It might sound funny, but the water we’re drilling into comes from underground rivers. They’re called “aquifers,” but they’re really just rivers, exactly like the ones we have above ground. And like every other river, they have different thicknesses, ups, downs, curves, and bends. That’s why we’re making an educated guess when we drill for water—it could be that your neighbor a mile down the road has a well with plenty of water, but you can’t find any… because the underground river has a bend in it that you can’t see.

Question: Is there such a thing as drilling for water and simply not finding any?

Answer: Sometimes if you’re not finding water, you can just drill deeper… but not always. There are some areas near Fountain, Hanover, and east of Hwy 94 where you’ve only got one shot to hit the water just right, and if you don’t find get the exact spot, you can drill all day long and it won’t matter because you’ve missed it. But in a scenario like this, we would have already known that our chances were slim because we would have looked up the neighbors’ wells and found that they had the same issue.

When you run into a situation where you just can’t get any water at all, your only option is to install a cistern, and haul water in manually from somewhere else. The challenge there is that very few companies offer potable water delivery anymore, and most of the “fill your own” water centers have closed. The good news though, is that it’s usually easy to find water in the Pikes Peak area.

Question: Do wells ever run dry?

Answer: They usually don’t. Sometimes we do get calls to come out and re-drill a well because the old one ran dry, but that’s usually because it’s a very old well with an old casing that has collapsed on itself. Modern wells are very solid: they have the proper seal out, they have 42 feet of upper steel, they go deep into the aquifer, they’re airtight, and they last a very long time. There are some cases where aquifers run out of water, but these are usually alluvial aquifers, which are extremely shallow and are essentially groundwater wells that farmers used to dig by hand. On average, in and around Colorado Springs, we drill to about 400 feet, so we don’t have this issue.

Question: Is well water truly “free”? Are there any costs to it besides drilling?

Answer: Once you’ve paid for your permit, and the for well itself, you don’t have to pay anyone for your water, ever. So in a sense, it’s free. Just don’t forget that well pumps run on electricity, and that costs money, especially since pumps generally run on 220 volts (or more), so that’s not free.

One nice thing about wells is that if you’re staying within the acre-foot limits specified by your permit, you won’t ever have watering restrictions. Watering restrictions sometimes happen to city residents during droughts in the summers in Colorado, but you’re insulated from it if you’re on well water.

The only big cost to be aware of when having a well is that it’s a mechanical system and the parts do wear out eventually. Pressure switches and capacitors burn out maybe every 5-10 years or so, but those parts cost about $20 each. The pumps themselves can burn out, and those cost several thousand dollars, but it’s important to keep in mind that the entire time you’ve had the well, you haven’t had a single water bill. Manufacturers say that well pumps will last 7-10 years, but honestly, I see them lasting 15-20 years on average. I personally replaced one a few years ago that had lasted 42 years!

Question: What is an average or acceptable amount of water flow on a well?

Answer: Most wells in the Pikes Peak region average 10-15 gallons per minute (GPM), although it always depends on where exactly you live. In some places like Black Forest and Cathedral Pines, wells can produce far more water than you can use, even as much as 50 GPM. But since the State of Colorado has a maximum limit of 15 GPM, that’s the most you can get. Those are unusual cases though, and what we see more commonly is a well that has a lower flow than you might want, maybe somewhere around 5-10 GPM. While you can certainly survive on this, it can affect your quality of life, so that’s when we install a cistern, which allows the homeowner to have a large reserve of usable water that’s constantly replenished throughout the day.

Sometimes a cistern is a nice option, but there are actually cases where they’re a requirement: in Colorado, if your well test shows a flow or 5 GPM or lower, most mortgage lenders will require that you have a cistern in order for them to provide your construction loan.

Question: How big is a cistern, what is it made of, and how it does it work with a well?

Answer: There are different materials you can use, but our company will only install concrete cisterns, and the standard size is 1,500 gallons. If a client needs more than that, we can install two or three of them inline and manifold them together (rather than just installing one large tank, which can be cost prohibitive).

With a cistern, you still have a well pump which brings water to the cistern, but you’ll also have another pump in the cistern that sends the water into the house. The well pump is controlled by a float valve in the cistern while the cistern pump is controlled by the call for water in the households’ domestic water system.

Question: If you live in the city, a water department oversees your water quality, filters it, and adds fluoridation and other things. Wells don’t have any of that. Is well water as good as city water?

Answer: It all depends on where you live, but well water is generally excellent. The building department (in Colorado Springs, that’s the Pikes Peak Regional Building Dept) requires a potability test before issuing a certificate of occupancy, so you’ll know if your water has any bacteria or contaminants before you even move in.

Usually there aren’t any contaminants in well water, but you might have minerals in it. Iron, for example, can give your water a metallic or bitter taste. But there are filtration systems you can install (in Colorado, we highly recommend Affordable Water Service for this) that can completely remove it. It’s amazing: terrible-tasting rusty red water goes into your system, and clear, sweet water comes out.

It is true that there isn’t fluoridation in well water, but I don’t see that as a problem. If you’re worried about that, you can take a fluoride pill, and brush your teeth with fluoride toothpaste. Also, keep in mind that city water has chlorine added, which you don’t have with a well. Many wells need no filtration at all—it’s all filtered by nature, and you can drink the water straight out of the ground.

Question: For people to want to do more research on wells, what resources do you recommend?

Answer: The Colorado Division of Water is a great resource: you can go online to and do research on your specific area. You can find aqua maps, aerial photos, and you can look up well permits. This can be especially helpful if, for example, you’re going to buy a home with an existing well. You can do a search to make sure a permit was pulled properly, as well as learn what substrate was drilled through (sand, rock, clays, coal, quartz, etc), what kind of pump was installed, and whether there was protection from groundwater, etc.

Question: What are some common mistakes or pitfalls you see with wells?

Answer: Here are three things that people should be aware of:

  1. It’s crucial to check on your water rights ownership. For example, if you buy a home in a subdivision that uses a municipal well, you are owed a certain percentage of water. When you close on the home, you want to make sure that the documentation is in your name. A lot of people forgot to pay attention to this, and I’ve seen it many times where someone buys a house, but the seller is still the legal owner of the water rights. You don’t want this to happen to you—pay close attention to your water ownership documentation at closing.
  2. Don’t try to modify or repair your well system on your own. I’ve seen many times where homeowners will try to increase their well pressure, and they literally blow up the pressure tank because they don’t know what they’re doing. I’m a firm believer in taking my car to the mechanic since I don’t know what goes on under the hood, and I think the same should go for your well. You really shouldn’t be messing with it if you’re not a well professional.
  3. The most common call for service we get is where people say “Our water pressure has dropped significantly,” and they think there’s something wrong with the system. Usually, this just means they have a filtration system in place but forgot to change the filter, which has plugged up because it’s full of sediment. 80% of the time, that’s what’s going on. The other call we get most often is that there’s no water at all, which usually means a pressure switch has burned out, but as I mentioned, this is a very cheap fix.

Question: Are there any unique aspects to drilling for water in Colorado that people moving here from elsewhere would find surprising?

Answer: Yes, in many other places—take Kansas, for instance—you’ve got a nice, flat surface, with lots of sand and shale, and you can drill a shallow well and produce tons of water. Colorado is very different: here, we have sandstone and clays, water is not plentiful, and it’s hard to drill. For example, up in the mountains, you may literally have to set charges and blast through rock with dynamite and use hammer drills to get to water. Rock drilling like this is terrible: it can cost $60-80/ft and you’ll spend all that money sometimes to get a well that produces just 1/4 of a gallon per minute. Some people in those areas are very excited if they get a well that produces 1 GPM!

Colorado is very diverse when it comes to ground conditions, which is why I tell people to call a well driller before buying your land. We can give you a good idea ahead of time so you know what you’re getting into. In other states, well drillers can just give you a cost estimate over the phone with a price per foot, because it’s always the same. In Colorado, there’s no way—we have to be very careful and give specific quotes based on your exact location.

Question: What final thoughts do you have for people who need a well?

Answer: If you’re going to have a well drilled, don’t try get a permit on your own—call a drilling company first. We can be very helpful with letting you know how the process works, and the best way to go about it. And if you call us ahead of time, we’re happy to give you the information you need on your exact lot, all for free. Research done ahead of time prevents expensive mistakes.


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