624 Pierce Street
Twin Falls, ID 83301
208-733-4744
FAX 208-736-0795
walkerws@mindspring.com
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Dry Wells

In the well drilling business, two of the most dreaded words are "dry well." Maybe it's because well owners don't have any control over a well going dry. Maybe it's because it means an expensive repair or replacement.. Maybe it's because a dry well affects everything you do, from cooking meals at home to running a business.

Until this year, we've only seen a few wells actually go dry in the 60-odd years we've been in business. But as the Western US Drought rolls on, we're starting to see more of them. With less rainfall, there's less water seeping through the ground to recharge the aquifer.

Drilling a new well is pretty expensive, and we don't want folks to spend that kind of money unless they have to. So we thought we'd put out some information so that you can make an informed decision about how to handle things if your well goes dry.

Symptoms of a Dry Well

However - and this is important - just because your water system has these symptoms, it doesn't always mean your well is going dry.

How to tell a Dry Well from a Pump Failure

We've heard stories that, by ignorance or by design, folks have had a new well drilled that they might not have needed. In these stories, the driller is quick to "get the new one drilled and the old one filled" before the owner can get a second opinion. However, at Walker Water Systems, we want to make sure our customers get the best system for their money. Often, that can mean spending less money fixing your existing well instead of paying for a new one.

For example, if you have air in your water, it might be a dry well. But more often that not, the problem is either a hole in the pipe or a bad check valve. The only way to tell is to pull the pump out and examine it. Spending a couple hundred dollars to examine and repair your system is a lot more economical than spending several thousand on a new well!

One easy way to see if the well is going dry is to lift the pipe out of the pitless adapter and run it for a while. That's typically a job that takes a truck with a derrick, and we're happy to come take a look if you call us. First, we lift up the pump about 5 feet and check to see if there's standing water in the pipe. If there's no water at the top of the pipe, then we know that it's probably a hole or a failed check valve. If you're worried about a dry well, this is good news - it'll probably save you a big chunk of change.

So let's say we have the pump lifted up and we've got water in the pipe. The next step is to turn on the pump and let it run. If it pumps for a few moments and then runs empty, that's bad news - your well is pumping down. But - if you can run the pump for 30 minutes or so without it going dry, then your well is probably OK.

So you've got a Dry Well...

What's Happening Underground?

Here's a cross-section of what things look like underground before you turn the pump on. Water flows through the aquifer (blue), which is really a mix of broken rock and sediment that's soaked with water.. The top of the aquifer is about the same as where the water sits in your well. That point is called the static water level, or sometimes the pumping level.

Normal Groundwater

When we configure a water system for a new well, we have to figure what depth it's pumping from. The pump only has to lift water from the pumping level to the surface, so we figure the size of the pump based on the static water level.

A quick note: Not all pumps are created equal. Not only do they have different horsepower, they also are designed for different amounts of water, and are designed to pump from different depths. We make sure to optimize the pump to the specifications of your well and water system. See our Pumps page for more information.

When you turn your pump on, this is what happens to the water in the aquifer:

Aquifer Drawdown

The pumping level / static water level drops because your pump is pulling water out of the well. This is called drawdown, and the area affected by the pump is called the cone of depression. The shape of the cone depends on what kind of rock and soil you have in your area. The cone shows how far away your well affects your neighbors, and it also gives you an idea of how long it takes to recharge after your pump turns off.

What does the Water Level have to do with a Dry Well?

First of all, if there's less water in the aquifer, you might be pumping out so much water that the water level drops down to the same level as the pump. The pump then starts sucking air, like a straw in the bottom of an empty soda cup. This can lead to air in your water or running out of water while the sprinklers are running.

Another thing that can happen when the water level drops is that the column of water in your pipe gets heavy. That doesn't sound like a problem, until you consider the pumping level. Think of it like trying to suck water up a straw 100 feet high. If your water level was 60 feet down, and now it's 100 feet down, the difference in the height means the pump has to lift the water higher. That makes the water in the pipe a lot heavier, and it means the pump has to work harder to lift the water up to the surface. If the pump is doing all its work lifting that extra weight, it then it can't build up as much pressure - making it run for longer periods. It's even possible that the extra weight of the water is too much for the pump to lift, especially for older and worn pumps.

What do I do now?

Even if your well is pumping down, you might not have to drill a new one. Here are some alternatives:

Reduce Water Usage

If you can cut back on the amount of water you're using, you can limit how far the well draws down. This might help you get by until the aquifer can recharge. Installing flow restrictors or appliances that use less water (including showers, toilets, and sprinklers) is one good way to reduce water usage. Another is to change your habits, such as turning off the water while brushing teeth, or reducing the time you run the sprinklers.

If you've had several dry years, everyone's wells in the area might be pumping down. It may be that your well is low because of your neighbor's water usage. If that's the case, you might talk with your neighbors about sharing water or using sprinklers at different times.

Setting the Pump Deeper

This is not always an option. If it's a Walker Water well, there's a good chance that it has space at the bottom that will let you set the pump a little deeper. Even if that's the case, you still might have to buy a bigger pump to lift the heavier column of water. It would cost some money, but might be a less expensive alternative to an replacement well.

Wait for the Aquifer

It might be that, after several dry years, the aquifer is a low. Climatologists suggest that Idaho's weather comes in cycles, so if you can reduce your water usage until the next rainy cycle, your water level might go back to normal and save you a lot of money.

Deepen or Replace the Well

We hesitate to advise this as an option because of the cost. But we know there are drillers in the area who are quick to suggest drilling a new well, so here are some tips on well replacement.

First of all, some wells can be drilled deeper, and some can't. If you have a Walker well, it's probably straight and clean enough that we can get tools to the bottom of the well and drill deeper. Some conditions might limit this, such as the condition of the casing, or if the well has a screen, or other down-well conditions. If there are issues on the surface, such as if the well was drilled through a cistern, we probably can't set back over it. Also, we've run into wells drilled by others in the area that are crooked, or that tend to cave in. Because drill tools tend to get stuck in these wells, we might not be able to set over them safely.

If your well runs dry, drilling a replacement is always an option. At Walkers, though, we try to avoid it unless there really is no alternative. If the first thing your regular pump guy suggests is drilling a new well, espcially without troubleshooting, it might be a good idea to get another set of eyes on it. Paying for a service call to get a second opinion could save you a lot of money.