---
title: "Rural village demand, survey 2070 BS, base year 2073"
subject: "Water Supply Engineering"
chapter: 3
key: "semester_5/water_supply_engineering:demand-as70"
source: https://www.bctengineer.com/q/semester_5/water_supply_engineering/demand-as70
site: BCT Engineering
---

# Rural village demand, survey 2070 BS, base year 2073

Water Supply Engineering · Chapter 3: Quantity of Water

- Asked in: 2070 Asar, 8 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/water_supply_engineering/demand-as70
- Whole chapter: https://www.bctengineer.com/md/semester_5/water_supply_engineering/chapter-3

## Question

In a rural village, the survey is carried out in the year 2070 BS and the following data is obtained: Population = 5000 nos; No of cows = 50 nos; No of goats = 250 nos; No of chickens = 2000 nos; No of VDC offices = 2 nos; No of tea shops = 3 nos; No of schools = 2 with overall 350 day scholar students; Annual population growth rate = 1.5% and annual growth rate for students = 1%.

If the base year is taken as 2073 BS and the design period is of 20 years, calculate the total water demand of the village for the service year.

## Short answer

Service year 2093 BS, n=23; population 7042, students 440. Net demand 325385 l/d; adding 15% losses gives 374193 l/d = 374.19 m3/d = 4.33 l/s.

## Answer

Survey year 2070 BS, base year 2073 BS and design period 20 years: the service (design) year is $2073+20 = 2093$ BS, which is 23 years after the survey.

#### Population and students in the design year
$$
\begin{aligned}
P_{2093} &= 5000\times(1.015)^{23} = 7{,}042\\
S_{2093} &= 350\times(1.01)^{23} = 440
\end{aligned}
$$

#### Water demand
**Design values assumed** (Nepal rural water supply practice): domestic 45 lpcd (public taps); day scholar 5 l/d; boarder 45 l/d; office staff 45 l/d with 10 staff per office; big animal (cow, buffalo) 45 l/d; small animal (goat, pig) 5 l/d; poultry 0.2 l/d; health post 1000 l/d; tea shop 500 l/d; losses and wastage 15% of net demand; maximum day factor 1.5 and peak hour factor 3. Livestock numbers are taken as constant.

| Demand | Quantity | Rate | Demand (l/day) |
|---|---|---|---|
| Domestic (45 lpcd) | 7,042 | 45 l/c/d | 316,885 |
| Day scholars | 440 | 5 l/c/d | 2,200 |
| Cows | 50 | 45 l/d | 2,250 |
| Goats | 250 | 5 l/d | 1,250 |
| Chickens | 2,000 | 0.2 l/d | 400 |
| VDC offices (10 staff each) | 20 | 45 l/staff | 900 |
| Tea shops | 3 | 500 l/d | 1,500 |
| **Net demand** | | | **325,385** |

Losses and wastage $= 15\%$ of net demand $= 48{,}808$ l/day

$$
Q_{avg} = 325{,}385 + 48{,}808 = 374{,}193\ \text{l/day} = 374.19\ \mathrm{m^3/day} = 4.33\ \text{l/s}
$$

**Answer: Total water demand of the village in 2093 BS = 374 m$^3$/day (4.33 l/s), for a design population of 7,042.**

## Check yourself

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

1. Survey 2070, base year 2073, design period 20 years. What is n from the survey?
   A. 20 years
   B. 3 years
   C. 23 years (service year 2093)
   D. 43 years
   Answer: C. Service year = 2073+20 = 2093; 2093-2070 = 23. (Key point: Service year)

2. How are the school students projected?
   A. 350 x (1.015)^23
   B. 350 x (1.01)^23 = 440 using their own 1% growth
   C. Kept constant at 350
   D. As 5% of village population
   Answer: B. The students have a separate growth rate; livestock numbers are kept constant. (Key point: Student growth)

3. What demand is used for 3 tea shops and 2 VDC offices?
   A. Tea shops 3 x 500 = 1500 l/d; offices 20 staff x 45 = 900 l/d
   B. Tea shops 3 x 45; offices 2 x 1000
   C. Tea shops 3 x 1000; offices 2 x 500
   D. Tea shops and offices are neglected
   Answer: A. Tea shop 500 l/d each; offices 10 staff each at 45 l/staff. (Key point: Shops and offices)

## Related in Water Supply Engineering

- [Demand of village 2070 BS, base period 5 years](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-c70) — Water Supply Engineering, chapter 3
- [Rural village demand for 2092 BS, incremental method](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-k78) — Water Supply Engineering, chapter 3
- [Total demand, village survey 2013, design 15 years](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-c69) — Water Supply Engineering, chapter 3, asked 2×
- [Average demand, village survey 2013, design 25 years](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-c73) — Water Supply Engineering, chapter 3, asked 2×
- [Demand of rural area survey 2019, 1.77% growth](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-b78) — Water Supply Engineering, chapter 3
- [Demand of rural municipality, base period 3 years](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ademand-bk79) — Water Supply Engineering, chapter 3

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