This course will examine current conditions and trends in water and sanitation services in low and middle income countries. Within it we will take a critical look at the underlying political, economic, social, and technical reasons why almost a billion people lack access to improved water supplies and almost 2 billion still do not have improved sanitation services.
Video 6.0: Possible Solutions to the Water Development Paths Exercise
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來自 University of Manchester 的課程
发展中国家的水供应和卫生政策
61 個評分
從本節課中
Development Paths for Water and Sanitation Services
與講師見面
Prof Dale WhittingtonProfessor
Manchester Business School
Dr Duncan ThomasLecturer
Alliance Manchester Business School
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In this video, I'll discuss the exercise
you've just done on water development paths.
There is no one right answer to this exercise.
Professionals from different disciplines, bring
different perspectives and different approaches
to the question of how to sequence water and sanitation investments.
To recap, we asked you to consider a small market town in Africa or South Asia.
The community is opening up to outside markets, economic activity is increasing.
But currently there is no water or sanitation infrastructure.
Households and businesses collect surface water from nearby streams.
There is no improved sanitation, and open defecation occurs outside town.
Some households and businesses have crude, unimproved pit latrines.
The question to answer is, how should the community
plan over the long-term, for improved water and sanitation infrastructure?
This table shows 12 cases of water and sanitation infrastructure combinations.
The excessive seems that the community starts in Case 1, in the top left cell.
Case 12, the cell in the lower right corner, represent the case
where household and business have pipe
water segmentation connections, and waste water treated.
One way to conceptualize your tasking in this excessive is to
draw arrows from a pathway, from Case 1 to Case 12.
On the other hand, you don't necessarily need to go all the way to Case 12.
You might conclude that the best pathway would be to stop, before reaching Case 12.
It's hard to define the best pathway without considering costs.
In this table, we've added some indicative costs,
expressed in US dollars per household per month.
Note, that the water costs are not cumulative, because having a
private water connection does not require, a public tap or hand pump.
It would thus be possible for a household to jump, directly from Case 1 to Case 3.
But sanitation costs are cumulative.
For example, the third level, C, of
sanitation, includes the cost of in house plumbing.
That's a water-sealed toilet, plus neighborhood waste water collection.
There are four main pathways through this table.
There's no consensus within the water community as
to which is best, or which should be preferred.
The first pathway is what we call, water first.
There are several reasons why a planner
might choose, a water first development path.
Water first development paths might provide
the greatest economic benefits, including time
saved from not having to collect water and opportunities for new businesses.
Water first paths are also one of the least expensive infrastructure sequences.
Water first pathways including going from Case 1to 2 to 3.
Then down the sanitation investments, from Case 6 to 9 to 12.
Or the water first pathway can mean, going directly to
piped water connections, thus skipping the intermediate water service in
Case 2, so you would then go Case 1 to 3, then to 6, to 9 and finally to Case 12.
Slightly less extreme water first paths would be to pick
up the intermediate sanitation service
level, after getting intermediate water service.
This would mean going from Case 1 to 2, then
to Case 5, then Case 6, Case 9, then Case 12.
Or the path could be from Case 1 to 2, to Case 6, then on to Case 9, then 12.
Public health professionals often choose to address the problem
of open defecation first, before attacking the water problem.
We call these pathways, health or sanitation first.
A health first development path would be, Case 1 to Case 4, then
to Case 5, Case 8, then to Case 9, and on to Case 12.
The associated cost will be, to go from Case 1 to 4.
$5, to Case 5 $10, to Case 8 $20 then to Case 9, $25
and finally to Case 12 arriving at $35 per household per month.
Another pathway often in favor by professionals in the water
sector, is to provide water segmentation together, at the same time.
We call this pathway, not one without the other.
The main not one without the other pathway, would be to go
from Case 1 to Case 5, then to Case 9 to Case 12.
A rational for this pathway is that people
typically want improved water services before improved sanitation.
But governmental owners, should only provide them together as
a package, to ensure that health benefits are achieved.
A disadvantage of providing improved water and sanitation at the same
time, is that it is more expensive than taking smaller steps.
Another way to think about the exercise is to look at
the problem from the perspective of households, not the social planner.
In other words, one way to design the water
and sanitation development path, is to provide what people want.
In most cases, this will likely be a water first development path, but it could be
any of the development paths we've already described
above, depending on local conditions, and on people's priorities.
Likely demand driven development paths, would be to go from Case 1
to 3, then to Case 6, and on to Case 9 and 12.
Or the path could be, Case 1 to Case 6, then to Case 9, and on to Case 12.
Another approach to choosing the development path, would be to use
economic analysis to guide the sequence of water and sanitation investments.
Thanks for watching this video.
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