A lining reduces the water a channel loses to seepage from 20-40% unlined to about 10-15% with puddled clay, 2-5% with stone and mortar, under 2% with concrete and under 1% with plastic sheeting. Clay lasts 5-15 years, stone and mortar 20-50 years, concrete 30-50 years or more, and plastic 3-10 years, so choose by how long the channel must last, what it carries and what material you have.
Part of Aqueducts and Channels
Lining materials are the surfaces applied to the bed and sides of a channel to stop water leaking out, soil washing away and weeds growing in. Each trades cost, life and effort differently.
Each Lining Trades Lifespan Against Cost And Effort
The aqueducts page tabulates the options:
| Material | Lifespan | Cost | Seepage loss | Best for |
|---|---|---|---|---|
| Puddled clay | 5-15 years | Free | 10-15% | Irrigation, clay-rich areas |
| Flat stones + mortar | 20-50 years | Moderate | 2-5% | Permanent drinking water supply |
| Concrete (3 cm) | 30-50+ years | High | Under 2% | Main supply channels |
| Plastic sheeting | 3-10 years | Low-moderate | Under 1% | Quick temporary lining |
Unlined earth channels lose 20-40% (Earth Channels).
What The Percentages Mean In Litres
Take a 5 L/s intake. Using the percentages as losses over the whole run (an assumption, since the page does not state the length):
| Lining | Loss | Delivered |
|---|---|---|
| None | 20-40% | 3.0-4.0 L/s |
| Clay | 10-15% | 4.25-4.5 L/s |
| Stone + mortar | 2-5% | 4.75-4.9 L/s |
| Concrete | under 2% | over 4.9 L/s |
| Plastic | under 1% | over 4.95 L/s |
What You Need
- A purpose: irrigation, drinking supply or temporary diversion
- A realistic life: how long must the channel work?
- The materials in reach: clay, stone, cement, sheeting
- The skill and time to build it and to cure it where needed
Method: Decide By Purpose, Life And Supply
Step 1: State what the channel carries. Drinking water needs a lining and a cover (Covered Aqueducts).
Step 2: State how long it must last. A temporary diversion does not need 50 years.
Step 3: List what you can get: clay (Clay Lining), stone and cement (Stone Aqueduct, Concrete Lining), sheeting (Plastic Lining).
Step 4: Choose the one that meets the purpose and the life with the effort you can supply.
Worked Example
Irrigation channel, 3 years of use, clay in the ground, no cement: puddled clay at 10-15% loss is free and lasts 5-15 years. Permanent village drinking supply: stone and mortar or concrete with a cover, since neither clay nor plastic is recommended for it.
Common Mistakes
- Lining a channel with a bad grade. The lining fixes the leaks, not the slope.
- Using clay for drinking water. It is rated for irrigation.
- Exposed plastic in sun. It breaks down in a few years.
- Overlooking the cure for cement linings.
What’s Next
- Learn next: Clay Lining — the cheapest option
- Combine with: Lined Channels — what a lining does to the flow