---
title: "Advantages of surface and sub-surface irrigation"
subject: "Irrigation and Drainage Engineering"
chapter: 1
key: "semester_6/irrigation_and_drainage_engineering:surface-subsurface-pros-cons"
source: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/surface-subsurface-pros-cons
site: BCT Engineering
---

# Advantages of surface and sub-surface irrigation

Irrigation and Drainage Engineering · Chapter 1: Introduction

- Asked in: 2062 Baisakh (old course), 4 marks
- Video: [Surface and sub surface irrigation in hindi.||by Civil Engineering.](https://www.youtube.com/watch?v=A-o9giWVKAc) — Chaityendra Singh
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/surface-subsurface-pros-cons
- Whole chapter: https://www.bctengineer.com/md/semester_6/irrigation_and_drainage_engineering/chapter-1

## Question

Write down the advantages and disadvantages of surface and sub-surface irrigation.

## Short answer

Surface irrigation: low cost, simple, but efficiency40-60%, high evaporation, levelling needed, labour-intensive. Sub-surface irrigation: high efficiency70-80%, no surface evaporation or cultivation hindrance, but costly, limited to suitable soil/topography, risk of salt accumulation and clogging.

## Answer

| Aspect | Surface irrigation | Sub-surface irrigation |
|---|---|---|
| Cost | Low initial cost | High initial cost |
| Water use | Efficiency 40-60% | Efficiency 70-80% |
| Evaporation | High | Very small |
| Land needs | Levelling needed | Flat land, high water table |
| Farm operations | Disturbed by channels | Not disturbed |
| Salinity risk | Moderate | High if drainage is poor |
| Skill needed | Little | More technical skill |

#### Surface irrigation
**Advantages:** simple, cheap, uses gravity (no energy), suits most crops and soils, easy to operate and learn.
**Disadvantages:** low efficiency, runoff and percolation losses, levelling is needed, waterlogging and erosion on slopes, labour-intensive, weeds grow in wet channels.

#### Sub-surface irrigation
**Advantages:** saves water, no surface evaporation, no hindrance to cultivation, no weeds on the surface, good aeration and uniform moisture.
**Disadvantages:** high cost, limited to special soil and topography, salt accumulation, pipes clog or get damaged by roots, control and checking of water distribution is difficult.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Compared with sub-surface, surface irrigation has:
   A. High initial cost
   B. No need for levelling
   C. Low initial cost
   D. Efficiency of 70-80%
   Answer: C. Sub-surface needs pipes and special conditions. (Key point: Cost comparison)

2. Typical efficiency of surface irrigation is:
   A. 70-80%
   B. 85-95%
   C. 95-100%
   D. 40-60%
   Answer: D. Sub-surface is 70-80%. (Key point: Efficiency)

3. Which method disturbs farm operations?
   A. Surface, because of channels
   B. Sub-surface
   C. Neither
   D. Both equally
   Answer: A. Sub-surface has nothing on the surface. (Key point: Farm operations)

4. Salinity risk is high in:
   A. Surface irrigation always
   B. Sub-surface irrigation with poor drainage
   C. Neither method
   D. Only drip
   Answer: B. Salts accumulate in the root zone. (Key point: Salinity risk)

## Related in Irrigation and Drainage Engineering

- [Surface and sub-surface irrigation methods](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Asurface-subsurface-methods-suitability) — Irrigation and Drainage Engineering, chapter 1, asked 11×
- [Short note: Sub-surface irrigation](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Asubsurface-irrigation-note) — Irrigation and Drainage Engineering, chapter 1
- [Surface methods and furrow irrigation](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Afurrow-irrigation-methods) — Irrigation and Drainage Engineering, chapter 1, asked 11×
- [Design criteria of surface drainage](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Asurface-drainage-design-criteria) — Irrigation and Drainage Engineering, chapter 9

## Related in other subjects

- [Control of sub-surface water and seepage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asubsurface-drainage-measures) — Transportation Engineering I, chapter 4, asked 15×
- [Direct methods of sub-surface investigation](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Adirect-subsurface-methods) — Engineering Geology II, chapter 4, asked 3×
- [Surface versus sub-surface investigation](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Asurface-vs-subsurface-investigation) — Engineering Geology II, chapter 4, asked 3×
- [Surface versus sub-surface drainage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asurface-vs-subsurface) — Transportation Engineering I, chapter 4, asked 2×