How to design a Gravity Flow Water System
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"The market for photocopying machines is, at most, 5,000 globally.” (IBM to the future founders of Xerox, 1969)
If in 1,995 a census showed a settlement had 10,000 inhabitants, and in 2,005 showed it has 12,000, what would be the population forecast if you were designing a system for 2,040?
1.
Let´s work out the growth rate i: i = (P2,005 – P1,995) / (P1,995* t) = 100* (12,000 – 10,000) / (10,000 * 10) = 2%
2.
Let´s apply the formula starting with 2,005:
P2040 = 23,999 people.
2
An area of 1.3km in a city is being rapidly populated with immigration from rural areas. Before conditions get worse, basic services need to be provided. In other areas of the same city which have been populated by rural immigration, each family 2 occupies approximately 260m and averages 7 people. What is the population to be supplied? 1.
The peak density is: 2
2
2
7 people / 260 m * 1,000,000 m / 1 km = 26,923 people / km 2.
The population will be:
2
2
2
1.3 km * 26,923 people / km = 35,000 people
3. 3 MAXIMUM DESIGN FLOW Very briefly, there are 3 ways to determine the design flow, depending on the situation:
© Santiago Arnalich
Arnalich. Water and habitat
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