---
title: "Rural and urban scheme layout diagram"
subject: "Water Supply Engineering"
chapter: 1
key: "semester_5/water_supply_engineering:rural-urban-scheme-diagram"
source: https://www.bctengineer.com/q/semester_5/water_supply_engineering/rural-urban-scheme-diagram
site: BCT Engineering
---

# Rural and urban scheme layout diagram

Water Supply Engineering · Chapter 1: Introduction

- Asked in: 2073 Shrawan, 4 marks; 2071 Chaitra, 4 marks; 2070 Chaitra, 4 marks; 2076 Asoj, 4 marks; 2068 Baisakh (old course), 4+4 marks; 2070 Chaitra (old course) (asked 6 times)
- Video: [How to Design Water Supply System - Part I](https://www.youtube.com/watch?v=FBu_DU-hK04) — Phil 4 Science
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/water_supply_engineering/rural-urban-scheme-diagram
- Whole chapter: https://www.bctengineer.com/md/semester_5/water_supply_engineering/chapter-1

## Question

Draw a typical schematic diagram of water supply schemes for rural and urban areas and briefly describe the function of each component.

## Short answer

Rural gravity scheme: spring → intake → sedimentation tank → reservoir → break pressure tank → public taps. Urban: source → intake → raw water pumping → treatment plant → clear water reservoir → pumping → elevated service reservoir → distribution network → house connections. Functions: intake collects, sedimentation removes solids, treatment ensures safety, reservoirs store and balance, distribution delivers.

## Answer

A water supply scheme collects water from a source, treats it where needed, and delivers it to consumers in adequate quantity and at adequate pressure. Rural schemes in Nepal are mostly gravity-based and simple; urban schemes need an intake, pumping, treatment and a pipe network.

#### Rural (gravity) scheme
```text
 [Source: spring/stream]
          |
 [Intake / spring box]
          |
 [Sedimentation tank]
          |  transmission main
          v
 [Storage/Reservoir tank]
          |
 [Break pressure tank] (if head high)
          |  distribution main
          v
 [Public standposts / tap stands]
```

#### Urban scheme
```text
 [Source: river/lake/well]
          |
      [Intake]
          |  raw water main
   [Raw water pumping station]
          |
  [Treatment plant: screen, sedimentation,
   coagulation, filtration, disinfection]
          |
   [Clear water reservoir]
          |
   [Pumping station]  -->  [Elevated service reservoir]
                                   |
                       [Distribution system]
                                   |
                        House connections
```

#### Function of components
| Component | Function |
|---|---|
| Source | Supplies raw water (spring, stream, river, lake, well) |
| Intake / spring box | Draws water from the source safely and keeps out debris and contamination |
| Raw water main / pumping | Carries or lifts raw water to the plant or tank |
| Sedimentation tank / treatment plant | Removes suspended matter, turbidity and germs so that the water becomes wholesome |
| Clear water reservoir | Stores treated water and balances plant output with pumping |
| Break pressure tank | Dissipates excess head to protect pipes and taps in steep terrain |
| Transmission main | Conveys water from the source or plant to the service area |
| Service (distribution) reservoir | Stores water to meet hourly variation, fire demand and emergencies |
| Distribution system | Network of mains, sub-mains and branches that delivers water to users |
| Public standposts / house connections | Final points of delivery to consumers |

In rural areas, treatment is limited to sedimentation and sometimes slow sand filtration and chlorination. In urban areas, full conventional treatment is provided, and pumping is used where the source is lower than the town.

## Check yourself

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

1. Why are rural water supply schemes in Nepal mostly kept simple?
   A. They are gravity-based and need little treatment
   B. They always use deep tube wells with pumps
   C. They need full conventional treatment plants
   D. They rely on elevated reservoirs fed by pumping
   Answer: A. Rural schemes are mostly gravity-based and simple, with treatment limited to sedimentation, sometimes slow sand filtration and chlorination. (Key point: Rural scheme type)

2. What is the function of a break pressure tank in a steep-terrain scheme?
   A. Stores water for fire fighting
   B. Dissipates excess head to protect pipes and taps
   C. Removes germs by chlorination
   D. Raises pressure at the taps
   Answer: B. A BPT dissipates excess head so pipes and taps are not overstressed in steep ground. (Key point: Break pressure tank)

3. In an urban scheme, the clear water reservoir mainly:
   A. Removes turbidity from raw water
   B. Draws water from the river
   C. Stores treated water and balances plant output with pumping
   D. Delivers water to house connections directly
   Answer: C. It stores treated water and acts as a buffer between the constant plant output and pumping. (Key point: Clear water reservoir)

## Related in Water Supply Engineering

- [Schematic diagram of rural gravity scheme](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Arural-gravity-scheme-diagram) — Water Supply Engineering, chapter 1, asked 5×
- [Typical water supply system and components](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Atypical-ws-system-components) — Water Supply Engineering, chapter 1, asked 4×
- [Necessity and impacts of water supply scheme](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Anecessity-impacts-ws) — Water Supply Engineering, chapter 1, asked 3×
- [Sources for hilly rural areas; river vs spring](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ahilly-rural-sources-river-spring) — Water Supply Engineering, chapter 2
- [Objectives of water supply and components](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aobjectives-ws-rural-diagram) — Water Supply Engineering, chapter 1, asked 3×
- [Rural area 22000 L/day river supply (question text cut)](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ares-a76) — Water Supply Engineering, chapter 7

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