gravity-fed potable water distribution system in san miguelito, guatemala engineers without borders...
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Gravity-Fed Potable Water Distribution
System in San Miguelito, Guatemala
Engineers Without Borders at the University of Wisconsin - Milwaukee
Background and Objectives• EWB@UWM collaborates with
La Asociacion to build water systems
• Quiche region of Guatemala affected by Civil War from 1960 – 1996
• Water hauled long distances by women and children
• Primary Goal: efficient and sustainable gravity-fed water distribution system with 20 year design life
• Secondary Goals: reduce water carrying burden and community education on sanitation, hygiene, and safe food preparation
4:00
AM
5:00
AM
6:00
AM
7:00
AM
8:00
AM
9:00
AM
10:0
0 A
M11
:00
AM
12:0
0 P
M1:
00 P
M2:
00 P
M3:
00 P
M4:
00 P
M5:
00 P
M6:
00 P
M7:
00 P
M8:
00 P
M9:
00 P
M10
:00
PM
11:0
0 P
M12
:00
AM
1:00
AM
2:00
AM
3:00
AM
4:00
AM
0
2,000
4,000
6,000
8,000
10,000
12,000
San Miguelito 10 m3 Distribution Tank 2035Storage (L) Demand (L/hr) Overflow (L/hr)
Time of Day
Vo
lum
e (l
iter
s)
Design Challenges and Solutions• ~1000 foot elevation change
from distribution tank to end of distribution lines
• Large pressure build up but cannot use reducing valves
• Break pressure tanks are simple, cost effective solution
• Flow rate at houses dependent on location
• High flow at some houses, low or no flow at others
• Ficha functions as diffuser to regulate flow and pressure 0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0
840
860
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980
1000
San Miguelito Distribution Lines B/C and B HGL vs. Relative Elevation
HGL
Rel Elev
Horizontal Distance (m)
Rel
ativ
e E
leva
tio
n (
m)
SHARED LINE B/C
Outcomes• System Components: spring
box, conveyance line, chlorinator, distribution tank, distribution lines, break pressure tanks, valve boxes, tap stands
• System carries water over two miles
• Provides access via tap stands at houses for more than 270 people
• Locally sourced materials• No operating costs and minimal
maintenance• Support from La Asociacion and
monitoring from EWB@UWM