Newsletter and Technical Publications
<International Source Book On Environmentally Sound Technologies
for Wastewater and Stormwater Management>
1.2 Collection and transfer (Topic b)
How has Africa fared since the end of the Drinking Water Supply and
Sanitation Decade in 1989?
Coverage refers to the percentage of the population that has access to
collection and disposal of wastewater, with or without treatment. Table 1.10
indicates that sanitation coverage in the sub-Saharan Africa (SSA) increased
from 28% in 1980 to 36% in 1990. Today, access to adequate excreta disposal is
available to only about 35% of the population. Technologies used for the safe
disposal of excreta are mostly of the individual type, mainly septic tank system
and simple latrines. Communal systems, such as conventional and small bore
sewers are rare, and available in some urban high income areas only.
In communities where space is lacking, or no nearby reliable water supply is
available, the feasibility of water borne sewerage or even pourflush latrines
becomes questionable. Households seem to be more aware of these limitations than
many technical agencies. For example, in Kumasi, Ghana, more than 50% of
households preferred a ventilated latrine to a water-flushed toilet, because the
former does not depend on water, is simple and does not break.
The population of Botswana is over 200,000 and still growing
at 12% per annum. The capital Gaborone is fully sewered, but roughly half of its
households have chosen not to connect to it. This is largely due to
affordability, for in-house water and sewerage connection raises SHHA plot cost
Table 1.10: Water supply and sanitation coverage in Africa
(a) Coverage for all sanitation types
(b) Coverage of full waterborne sewerage connections in some countries
||% population connected
||Available access is 100%; length
of sewer is 1.85 km /1000 persons
|| % of national population
||See Table 10.
||DANIDA project: Busia, Homa
Bay,Isiolo and Nyahururu .(See Table 22).
|Malawi/all urban areas
||100; whole territory (75)
|| Abuja City in Wupa
drainage district houses 200,00 people.
||Population of 90,000
|South Africa/all towns and
||Ratio of all urban population
(totalling24.5 million in 1990.
|South Africa/North Cape
||For the whole province.
|South Africa/Western Cape
|| Out of a total urban
population of 3.156 million in the province.
|| ~ 100
|| High income dwellers who
have large plots of >2,000m2 are allowed to have preferred septic
tanks; length of sewer is 4.1 km/1000 persons
|Note: Blantyre and Lilongwe each has a water
board. Donor environment appears favourable: as many donor organizations
have provided financial assistance through grants and loans The donors
include World Bank, UNICEF, UNDP, USAID, DANIDA, EEC, ADB, CIDA, British
and French governments.
In 1992 per capita water consumption in Harare was 73 l/c/d for high density,
200 for medium and 311 for low density residents. On the average Harare water
users pay $0.15/m3, less than 25% of the real marginal cost of the
water. The price of Harare water is based not on its cost, but on the anticipated
Virtually all the inhabitants of Harare’s recognized residential areas -
low and high density - have access to water-flushed toilets and almost all those
who need to be connected to sewers are connected. High income dwellers who have
large plots of 2,000m2 or more are allowed to have septic tanks if
preferred. This is an achievement not matched by any city with such a low GDP
When Gaborone was established in the mid-1960s, practically the whole of it
was sewered by a system of gravity sewers, with treatment facilities in a series
of waste stabilization ponds. Everyone could be connected to the sewer system,
but not all have been connected. The non-SHHA plots with roughly 50% of Gaborone’s
population, have water-borne flush toilets attached to the sewer system. The
SHHA plots (low-cost or low-income housing) with the other half of the
population, have pit latrines in their yards.
The core of every SHHA plot not connected to the sewer seems to be the VIP
toilet. Sludge removal frequency is once in 2-5 years, but in Gaborone, some
pits have to be emptied once a week and many of them once in a year.
Both Harare and Gaborone are fully sewered in the sense that almost everyone
could be connected up to the existing system. The length of sewer system in
Harare is 4.10 km per 1000 population, and Gaborone 1.85 km per 1000 persons.
The population of Addis Ababa is some 2.113 million. A sewerage system was
commissioned in 1981 to serve only the central part of Addis Ababa. It is a
small system with a capacity to serve only 200,000 users, but is not operating
at full capacity. The treatment plant is located at Kalitie and was designed for
just 50,000 people, but can be expanded to serve 100,000 and then
150,000-175,000 (World Bank, 1997).
The excessive growth of Dar es Salaam (8% p.a.) over-stretched the drainage
system and flooding frequently disrupted economic activities. In 1987 President
Nyerere had to intervene personally to immediately effect maintenance work on
the sewer network and drains. At that time most of the sewer network was
completely blocked by materials and only 2 of the 17 sewage pumping stations
were functional. Indeed, only 12% of Dar es Salaam’s population had access to
the choked sewers by the early 1980s while 8% used septic tanks and 80% had pit
latrines (Oyebande, 1990).