---
title: "Dead end distribution system"
subject: "Water Supply Engineering"
chapter: 7
key: "semester_5/water_supply_engineering:dead-end-system"
source: https://www.bctengineer.com/q/semester_5/water_supply_engineering/dead-end-system
site: BCT Engineering
---

# Dead end distribution system

Water Supply Engineering · Chapter 7: Reservoirs and Distribution System

- Asked in: 2078 Kartik, 4+4 marks
- Video: [Layouts of Distribution System | Dead end System | Grid System | Ring System | Radial system](https://www.youtube.com/watch?v=gwAfG-T30NM) — Civil Engineering Power
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/water_supply_engineering/dead-end-system
- Whole chapter: https://www.bctengineer.com/md/semester_5/water_supply_engineering/chapter-7

## Question

Describe the dead end system of water distribution with a neat sketch. Also point out its merits and demerits.

## Short answer

Dead end system has a main with branches ending in dead ends. Merits: simple design, low cost, easy maintenance. Demerits: water stagnation, interrupted supply during repairs, low pressure at ends.

## Answer

The dead end (tree) system is a layout in which one main runs from the reservoir through the town and sub-mains branch from it like a tree; each branch ends at a dead end and has no connection with other branches.

```text
         Sub-mains / branches
              |   |   |
  Reservoir ==============+=== Main
              |   |   |   |
           branches end (dead end)
```

#### Merits
1. Simple to design: the discharge in each pipe is known, so sizes are fixed without trial and error.
2. Fewer valves and less pipe length are needed, so the cost is low.
3. Easy to lay and maintain; the discharge and head loss are easily found.
4. Suited to towns that have grown without a planned pattern and to hilly or linear settlements, where it follows the roads.
5. Individual pipe diameters are economical, as the pipe size decreases away from the main.

#### Demerits
1. Water in the dead ends is stagnant, which gives bad taste, bacterial growth and sediment deposits. Scour/blow-off valves are needed at the ends and must be flushed regularly.
2. If a pipe breaks or is shut for repair, all consumers beyond that point lose supply.
3. Pressure at the far ends is low, and it varies with the demand on other branches.
4. Discharge for fire fighting is available from one direction only, so it is limited.
5. Extension of the system reduces the pressure in existing branches.

## Check yourself

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

1. What is the dead end system?
   A. Branches are interconnected in loops
   B. One main with sub-mains branching like a tree, each ending without connection to others
   C. Pipes radiate from a centre reservoir
   D. Pipes form a ring around the town
   Answer: B. It is a tree layout in which every branch ends at a dead end. (Key point: Definition)

2. Which is a merit of the dead end system?
   A. Uniform pressure everywhere
   B. Simple design with known discharge in each pipe, fewer valves and low cost
   C. No stagnation
   D. High firefighting flow
   Answer: B. Discharges are known directly so sizing is simple, and pipe length and valves are less. (Key point: Merit)

3. Why are scour valves provided at dead ends?
   A. To raise the pressure
   B. To flush stagnant water that causes bad taste and bacterial growth
   C. To measure flow
   D. To isolate branches
   Answer: B. Water stagnates at dead ends, so blow-offs allow regular flushing. (Key point: Demerit)

## Related in Water Supply Engineering

- [Distribution layouts, merits and demerits](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Adistribution-layouts-merits-demerits) — Water Supply Engineering, chapter 7, asked 6×
- [Three pipe materials with merits/demerits](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Apipe-materials-merits-demerits) — Water Supply Engineering, chapter 8, asked 4×
- [Design steps and criteria of distribution system](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Adistribution-design-steps) — Water Supply Engineering, chapter 7, asked 3×
- [Distribution layouts, pros/cons, improvements](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Adistribution-layouts-improvements) — Water Supply Engineering, chapter 7, asked 4×
- [Methods of distribution of water](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Amethods-of-distribution) — Water Supply Engineering, chapter 7
- [Grid iron system of distribution](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Agrid-iron-system) — Water Supply Engineering, chapter 7

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- [Merits and demerits of grid connected system](https://www.bctengineer.com/question.md?key=semester_8%2Ftransmission_and_distribution_system_design%3Agrid-connected-merits-demerits) — Transmission and Distribution System Design, chapter 1
- [Merits and demerits of interconnected system](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Ainterconnection-merits-demerits) — Power System Analysis II, chapter 1, asked 3×
- [LVDT with merits and demerits](https://www.bctengineer.com/question.md?key=semester_4%2Finstrumentation_i%3Alvdt-merits-demerits) — Instrumentation I, chapter 3
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