Ntchisi Gravity Fed System

This is the first post in the Technology Notes section of this blog, based off of a trip Garrett and I took to the Ntchisi Forest Reserve to check out a gravity fed system (GFS).

GFSs are all the rage in Malawi right now – they’re being built and rehabilitated across the country. We’re mostly interested in them because of their management structures (we want to learn how money is collected from users, who is responsible for the maintenance, and how the arrangement is set up). However, in this case, the technology was interesting enough to be worth discussing in and of itself.

The reason a GFS was chosen for this area was mountainous terrain. High in the mountains the water table is usually too low for normal wells (the standard water access technology choice in Africa), and this mountain was no exception. To get around this, a water system was set up by damming two springs near the top of the mountain, and routing the water through underground pipes to a series of taps in surrounding villages.

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Eston (system caretaker, front left), Garrett (EWB OVS, front right), and Peter Moyo (Ntchisi Assistant District Water Officer, back left) inspecting one of the dammed springs (labeled Headpond II on schematic below).

The two dammed springs allow water to collect in headponds, and then spill over back into the springs once they are full. The headponds outlet through pipes into a small sedimentation tank, which then outlets into a larger holding tank. Water from the holding tank is then distributed in two directions: there is a line going to 14 different taps in surrounding villages, and another line going to the Ntchisi Forest Lodge, a tourist establishment which is also on the mountain.

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Rough schematic of the system layout.

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Above-ground line running from Headpond II to the Sedimentation Tank

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Ntchisi District Water Office Driver (I’m embarrassed, I can’t remember his name) inspecting the Sedimentation Tank

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Peter standing next to the Storage Tank

All in all, a pretty impressive system for rural Malawi, at least in my opinion. According to Eston, the genesis of the system was the work of a Peace Corps volunteer (John Fort?), who lived on the mountain around 2005-2006 and worked on community mobilization for the establishment of a water system. At the time he left (due to illness, again according to Eston) he had helped the community develop a proposal for the system, and they were busy searching for a donor. Shortly thereafter, the District Government came in as part of Ntchisi’s recent Integrated Rural Water Supply and Sanitation Program (funded by the African Development Bank) and provided funding to construct the system.

One major word of caution though – the system was only finished about 5 months ago. How communities will collect money for its maintenance, who will undertake the maintenance, who will supply spare parts, and how those relationships will be established and maintained, is still very much up in the air. These are the questions we are in Malawi trying to answer. Many impressive water infrastructure projects have been built in this part of the world – making them last is the real challenge.

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3 comments:

  1. John Fort is indeed a real individual:
    http://peacecorpsonline.org/messages/messages/467/2044644.html

    http://peacecorpsonline.org/messages/messages/467/2019644.html

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  2. I lived in rural Ntchisi from 1967 through 1969 and would like to correspond.

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  3. I am indeed a real individual. It's great to hear that this Gravity Fed System has come to Ntchisi. Eston Ngoza is a great guy to be in charge of it.

    ReplyDelete