I read the information provided on the question. Recommend:
Get graphing paper and plot both the tank and water elevations (min and max) of all the locations using an appropriate scale (Hill #1, Tank #1, Hill #2, Tank #2, Valley Houses (floor), Hill Houses (floor)).
Recognize that water will flow from a higher level to a lower level with gravity.
Any restrictions to flow will reduce that flow and increase the time for a specific amount of water to flow through.
The greater the differences in levels, the greater the flow rate from upper level to lower level.
Once equilibrium is achieved (levels are equal), there will be minimal potential to no flow.
To move water from a lower level to a higher level, will need to exert force and work (a mover such as a pump to "push" the water to the higher level).
I hope this helps.
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Joseph Crisologo
Senior Homeland Security Engineer
State of CA, State Water Resources Control Board
Glendale CA
(818)551-2046
Original Message:
Sent: 04-11-2016 14:49
From: Brian Parsons
Subject: El Salvador water flow question
Good Afternoon:
I received the below message from a volunteer who has a question about water flow related to a volunteer project he is working on in El Salvador. Please be in direct contact with DonMontagna@... if you feel that you can assist. He is working with International Partners - Developing self-sustaining communities.
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International Partners - Developing self-sustaining communities |
El Salvador is a beautiful country that has been ravaged by pollution, erosion and waste. Its dense population, the civil war, and lack of employment opportunities are fueling a steady migration to the United States. |
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From: DonMontagna@... [DonMontagna@...]
Sent: Thursday, April 07, 2016 7:06 PM
To: ASCE Staff Member
Cc: pbeckman@...
Subject: El Salvador water flow question
Dear John,
I was delighted to find out that you might be able to help with a water flow question. I am a volunteer with International Partners, a small non-profit that works with rural Salvadoran communities of people living in extreme poverty. They are subsistence farmers, earning maybe $300 a year, and the women have always had to walk each day for water.
The community of Hacienda Vieja is making a proposal to improve the water delivery for a system that we had previously built. Our water projects are simple because they are gravity fed, but I am not sure if this one will work. Given very scarce resources, to spend money building this if it won’t work would be a travesty. Your help with this issue would have a substantially meaningful impact on the live of 300 desperately poor people. I cannot fully express my gratitude for you help with this.
Let me try describing their situation and proposal.
- On hill #1 there is a tank with sufficient water filling it from an ample spring a few miles away. There is no option for increasing the water into this tank or building another tank on hill #1, but there is enough water going into the tank #1 to serve all needs.
- Exiting tank #1 there is a pipe. The diameter of this pipe cannot be changed nor can there be another pipe added to exit tank #1. (Another community that also has a pipe exiting tank #1 will not allow any change and backs that up with violence. There are no police.)
- That exit pipe goes down the hill to houses that are along the valley floor where houses now get adequate water.
- However, on the far side of the community there are houses that do not get water because they are higher so that the gravity feed will not reach them.
- About 5 years ago, they (with IP help) built a second tank (#2) on a hill closer to the houses without water. The water pipe from tank #1 that feeds all houses in the valley was extended up the second hill, which is lower than hill #1, so that tank#2 gets water. From tank #2 water is then piped down to the houses not in the valley.
- The amount of water that gets into tank#2 supplies only enough for each house to get water a few hours a week, maybe 2-3 hours 2 or 3 times a week. Their goal is to increase the amount of water in tank #2 so that those higher houses have adequate water.
- Their plan is to run another pipe out of the pipe that exits tank #1. That new pipe would go a shorter route along a ridge and directly into tank#2, which is somewhat lower than tank#1. This would be instead of having only the pipe that goes down into the valley and up again to tank #2.
Here are the issues that concern my uneducated mind.
- Generally, will the water flow into the T joint across toward tank #2, or prefer to go down the steeper pipe into the valley.
- At night, when the water is not used by the valley houses, causing the downward pipe to fill, would the water then will flow through the higher pipe going directly to tank #2?
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Brian Parsons M.ASCE
Eng. Director
EWRI/ASCE
Reston VA
(703) 295-6071
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