Springs come in three working types: gravity springs, where water flowing through a water-bearing layer meets a slope and comes out at one place; artesian springs, where pressurised water from a confined aquifer rises through a crack; and seep springs, where water oozes from a broad wet area. A single flowing eye is captured with a spring box and a diffuse seep with collection chambers, so identify which you have before building anything.
Part of Spring Capture
A spring is a place where groundwater reaches the surface by itself. The way it reaches the surface decides how much water it gives, how reliable it is, how easily it is polluted and what kind of structure can capture it.
How The Water Gets Out Decides How You Catch It
Three types cover the cases you will meet most often:
| Type | How it forms | What you see | Capture |
|---|---|---|---|
| Gravity spring | A water-bearing layer (aquifer) meets a slope and the water flows out at the surface; the most common type | A clear flow from one point or line on a hillside, at the foot of a rock layer or a change in rock | A spring box (Gravity Springs) |
| Artesian spring | Pressurised water in a confined aquifer finds a crack and pushes upward | Water welling or bubbling up, sometimes forcefully, often in valley floors, flowing year-round | A box built to take the pressure (Artesian Springs) |
| Seep spring | Water oozes from a wide area instead of one point | A broad wet, boggy patch with no single flow | Collection chambers fed by drains (Seep Springs) |
The Phase 0 spring guide describes further field forms that are all variants of these: contact springs where permeable rock sits above clay, fracture springs in cracked rock, depression springs where the water table meets low ground, and karst springs in limestone (Spring Location).
The Type Also Tells You The Risk
Water that has filtered slowly through sand or sandstone is usually clean. Water in karst, which runs through dissolved channels in limestone, can carry surface contamination quickly with almost no filtering, and shallow gravity springs respond fast to rain. A spring that turns cloudy after rain is connected to the surface. Treat every spring as needing treatment until it has been tested (Community Water Testing).
What You Need
- Time in the dry season — to see the spring at its weakest
- A bucket and a watch — to measure flow (Bucket Timing)
- A spade — to expose the eye gently
- A notebook — for position, flow, clarity and what the ground is made of
Method: Look, Dig A Little, Classify
Step 1: Find where the water comes out. Follow wet ground uphill to the highest point where water appears.
Step 2: Clear the spot gently. Remove leaves and mud by hand. Do not dig the hole deeper; a spring can be damaged by digging too much.
Step 3: Classify. One point or line with a flow is a gravity spring. Water welling up with force from the ground, in low land, is artesian. A broad wet patch with no flow is a seep.
Step 4: Record the dry-season flow. The flow in the driest month is the figure that counts (Seasonal Monitoring).
Step 5: Choose the capture. Box for a point source, chambers for a seep.
Common Mistakes
- Treating a seep as a gravity spring. A box built round a wet patch collects little.
- Building in the wet season. The spring looks strong and the dry-season flow is a fraction of it.
- Digging too hard at the eye. The water finds another way out.
- Assuming spring water is safe. It needs testing and treatment.
Safety
Soft, wet ground and steep banks
Springs lie on slopes where wet ground slides. Do not dig into a bank deeper than 1.2 m without sloping or shoring it, and never undercut one. Keep spoil at least 0.6 m back from the edge, and do not work alone (Excavation).
What’s Next
- Learn next: Bucket Timing — measure the flow
- Combine with: Spring Box Construction — capturing a single flowing eye