At least the US is better off than many countries like India and China where availability of pure uncontaminated drinking water is reaching crisis proportions. Before developing the spring on your land it is good to have a bit of background on springs. Watch this to see what to look for when buying a property – basically go looking in the late summer and fall when temporary springs will have dried up, ask owners or the realtor to point out the exact location of springs or seeps and check them out for yourself:
What causes a spring to form?
It is important to know why a spring has formed on your property in order to work out how stable it will be in terms of delivering a set rate of water.
When rainwater falls onto permeable rocks that have cracks and fissures it will filter through those layers and collect in the form of underground pools and lakes. Sandstone and limestone are the most porous – think of cave systems and the underground rivers that flow through them, for example the Niagara Cave in Minnesota with it’s 60 foot underground waterfall. Granite and basalt will also hold water if there are enough cracks and fissures for the water to collect, even though the rock itself is impermeable. This process can take thousands of years for aquifiers to fill with water.
The role of aquifers
Underlying many parts of the world are huge aquifers but one needs to understand that water cannot be pumped out indiscriminately otherwise in coastal area saline water from the ocean which is usually at a lower level will start mixing with the fresh water and contaminate supplies. The deeper one goes down the more likely the water will be brine. Much of the water in the US comes from aquifers but considering much of that water dates from the last ice age we are using groundwater at unsustainable rates so aquifers are shrinking.
To check whether your land lies over an aquifer click here for a map of the most important aquifers underlying the US. When the water table is high and the aquifer is near to the surface the groundwater flows to the surface and pops out as a spring, usually along hillsides, low lying areas or at the base of slopes.
Four different types of springs you may encounter on your land
- Artesian Spring – This forms when the underground aquifer is full and the water has to escape somewhere and follows the line of least resistance through a crack or fissure in the land.
- Gravity spring – When rainwater percolates through the ground until it reaches an impermeable layer it flows along horizontally, slightly downhill, following gravitational pull until it finds an outlet – often you find them fairly high up on a hill side or cliff.
- Seepage spring – this forms over a large area and occurs when water reaches an impermeable layer and then simply oozes from the ground because it can’t move lower – so they are usually found near the bottom of hills or in shallow depressions. They are the hardest to develop as there is no one clear emergence point.
- Fissure springs occur along fault lines in the earth, where the water is forced to the surface either by warmer water underneath or simply because it follows the fissures to emerge at the surface thereby relieving the pressure. They are sometimes warm and can be known as fault spring or thermal springs, due to the heated ground underneath but they can also be cold.
Checking the rate of flow
Flow from springs can vary – when rainfall is high they run faster and in times of drought when the water table drops them may dry up until the next rains.
It is important to check the spring on your property and monitor the rate of flow before developing it further. You will be ideally looking for a perennial spring that supplies water year round. To work out the rate of flow, dig a little beneath the point where the spring exits the ground and place a bucket there –five gallons should be fine. Time how many seconds it takes for the bucket to fill up. From there you can work out how many gallons per second or per minute the spring can deliver and you are ready for the next step – testing the water.
Is the water suitable for human consumption?
Once you have found a spring that flows reasonably well that doesn’t mean it’s ready to supply your drinking water. Unfortunately advertising campaigns for pure bottled spring water have led us to assume that all spring water is the best for our health. Sadly this is not always the case. “Inadequate management of urban, industrial and agricultural wastewater means the drinking-water of hundreds of millions of people is dangerously contaminated or chemically polluted,” according the The World Health Organization’s June 2015 Drinking Water Fact Sheet No 391. First off, take a sample to a certified water testing laboratory to be thoroughly tested. Pennsylvannia State University suggests a number of tests.
Making the spring work for you
Once the tests are back you’ll know whether you have pure water suitable for consumption, or what steps are to be followed to purify the water. The next step is to start developing the spring.
If the spring isn’t perennial you can at least store the excess from the wet season to use during times of drought, but it’s advisable to back up with rainwater harvesting to ensure you have enough. Check the family requirements for water per day factoring in the number of people, appliances and how much water they use, and to what extent you are prepared to re-use grey water and where you will use it. Usually it is in the region of 50 to 75 gallons per day per person.
Materials needed to develop your spring
These are the general materials needed but they will vary from spring to spring depending on the type and distance to storage as well as slope of ground.
PVC pipe – the inside diameter will depend on the rate of flow from the spring – the stronger the flow the larger the diameter. This chart provides a handy reference.
- Stones (can be collected from the surrounding area if available).
- Gravel ½ inch to 2 inch
- Building sand to mix with cement.
- Plaster sand
- Waterproofing material
- Ready made spring box with fittings and lid or you can build your own from bricks and cement with a lid made from plywood that is fiber glassed over to make it waterproof or buy a plastic lid.
Step by step guide to digging your spring
Dig a diversion ditch about a yard above the eye of the spring that slopes away on either side to carry away excess rainwater that may pollute the spring with run off mud and plant matter. The ditch can be lined with stones to stabilize it.
Dig back from the point the water emerges to find the eye of the spring – where it bubbles up from the ground.
Place stones below the point where it emerges in a trench leading to the spring box. This can be open or can be covered over with gravel and plastic sheeting so sediment doesn’t get into the filter system.
Build a concrete wall around 18 inches high to contain the soil and in this wall place your length of PVC pipe that will go through the wall from the trench carrying the spring water on one side into the spring box on the other.
The spring box can be purchased ready made with the fittings or you can build your own. Set into the base of the spring box (dimensions should be around 3x3x4 feet) will be a drainage pipe so should any sediment that collect in the base of the box can be flushed out when you need to.
Stopper the end of the drainage pipe where it emerges on the downside of the spring box. You don’t want frogs and other creatures crawling up and blocking it nor do you want wasps making a nest in there.
On the inside of the spring box there will be a fitting with another pipe in it projecting upwards, so when you want to clean out the sediment all you do is remove the vertical pipe and out goes the sediment and water.
Around ¾ of the way up the down hill side of the spring box will be your pipe leading off to your containers for storing water and they will gravity feed the water to the house if it is downhill from there – otherwise if it is uphill you will need a pump.
The overflow pipe will be near the top of the downhill side of the spring box so should be flow from the spring be excessive the water can be lead off to a pond or other place to use the extra water for irrigating farmland. The overflow pipe should have a piece of gauze over the end that protrudes from the spring box so insects don’t make their way in there.
The lid of the spring box must fit snugly over the box so no water, insects or animals can get in and pollute the clean water. Also the spring box must be of opaque material so no light gets in otherwise algae will grow.
If you are in an area where there are bears make sure metal pipe is sleeved over the protruding PVC pipes from the spring box otherwise they might gnaw on the pipes – if they get through the fencing.
Once you have put in your spring box you need to make sure the whole area – about 10 yards up and downhill and on either side is fenced off so animals don’t get to the spring and pollute it with feces, and also so eroded matter can’t obliterate the spring. Make sure to plant the area with a creeping grass so there aren’t wash-aways. Animals that may have been drinking form the spring water can still get water from the overflow from the spring box if you lead it into some sort of container suited to all animals – an old bath may be ok for cows and goats but other wild creatures can’t reach so make sure there are shallow containers or a pond is developed.
Remember if you get too greedy and try to contain all the water from the spring the spring could dry up as it finds another path of least resistance – and that may not even be on your property! Make sure the overflow water can flow away quickly to a pond or other catchment system. Also make sure no open toilets or animal pens are sited above the point at which the spring emerges.
Watch this video for tips on how to develop your spring:
Is a spring box necessary?
Lots of people advise using a spring box but it may not be absolutely necessary – it depends on the topography and rate of flow. There are other options, the simplest and cheapest being a small trench lined with stone or cement or tiles leading from the eye of the spring to a large bowl which can be emptied by hand if sediment collects – from the bowl a pipe will lead to storage containers. There are various other options.
The Neverending Cycle of Water
The whole point of a spring is to use water on your property that is probably bubbling up from an aquifer or is the result of excess rainfall not finding its way down through the rock layers into an aquifer. Excess rainwater should be contained by swales – we cover this thoroughly in My Survival Farm, so the water remains on your property and can percolate downwards to keep feeding the aquifer beneath that feeds your spring. The cycle of water is neverending – the pure spring water you drink today is probably from the last ice age.