HARVESTING ROOFTOP RUNOFF FROM RDP HOUSING IN SOUTH AFRICA: A PRAGMATIC APPROACH TO SUPPLEMENT WATER SUPPLY WHILE REDUCING FLOODING, SOIL EROSION, AND DISEASE
Impact/Purpose:
In South Africa, millions of people live in poverty and reside in shanty towns. To address this
issue, the Reconstruction and Development Programme (RDP) was established to provide
housing for impoverished citizens. The RDP has built more than 1.7 million homes but there
remains a serious housing shortage. Many of the RDP houses have corrugated metal roofs with
no gutters and are built in areas with steep slopes, poor drainage, or high water tables. Soil
erosions, flooding, and water borne diseases are problems in these new housing communities.
Most residents are impoverished and quickly use their free monthly water supply allotment.
Efforts to establish individual or community vegetable gardens are hampered by a lack of
resources and inadequate rainfall. The goal of the project is to design a rain water collection unit
that will collect runoff from rooftops and then distribute this water for use in flushing toilets and
irrigation of gardens.
Description:
The team was able to design a shuttle valve and full scale rainwater collection system that, in times of enough rainfall, provided an extra free source of water to flush toilets. Based of the dimensions of the RDP house and the tank size, the system should be able to collect roughly 19,900 liters of water per year for flushing toilets. The team will create the full scale design in Ohio this month and perform tests on the efficiency and effectiveness of the rainwater collection system.
Record Details:
Record Type:PROJECT(
ABSTRACT
)
Start Date:06/09/2006
Completion Date:07/10/2008
Record ID:
200807
Keywords:
TECHNOLOGY FOR SUSTAINABLE ENVIRONMENT, HYDROLOGY, IRRIGATION, RAIN
BARRELS, CAPSTONE DESIGN COURSE,
Related Organizations:
Role
:OWNER
Organization Name
:OHIO STATE UNIVERSITY - MAIN CAMPUS
State
:OH
Project Information:
Approach
:The project will be conducted by engineering students as part of a
capstone design sequence of courses. A collaborative study has been initiated with faculty and
staff at the University of Kwa-Zulu Natal (UKZN). In the summer of 2006, the project team
visited South Africa. Initially, in Ohio, a portion of a roof will be constructed and runoff
collection and redistribution systems will be evaluated. Components that will be designed and
evaluated include: (1) the gutter systems and methods to connect the gutter to the corrugated
roof; (2) debris, animal, and reptile screens; (3) the size, construction, and elevation(s) to locate
the rainfall collection devices; and (4) self-sustaining distribution systems. For safety and
practical reasons the collection tanks will not be attached to these concrete block RDP houses.
A multitank system that includes an elevated small tank for water to flush a toilet. Excess water will go to larger tanks that supply water for irrigation purposes. Low cost,
durability, practicality, and sustainability are key issues that will be evaluated. Following initial
evaluation in Ohio, the design team will return to South Africa and a prototype system will be
installed and evaluated on several RDP houses, and alternative housing approaches, that are
being studied by students and faculty at the UKZN. The reliability and durability of proposed
designs will be evaluated using a probabilistic risk assessment methodology. A comparative
evaluation of costs for each design will be conducted using a cost-benefit analysis.
Cost
:$9,998.00
Research Component
:Pollution Prevention/Sustainable Development
Approach
:The project will be conducted by engineering students as part of a
capstone design sequence of courses. A collaborative study has been initiated with faculty and
staff at the University of Kwa-Zulu Natal (UKZN). In the summer of 2006, the project team
visited South Africa. Initially, in Ohio, a portion of a roof will be constructed and runoff
collection and redistribution systems will be evaluated. Components that will be designed and
evaluated include: (1) the gutter systems and methods to connect the gutter to the corrugated
roof; (2) debris, animal, and reptile screens; (3) the size, construction, and elevation(s) to locate
the rainfall collection devices; and (4) self-sustaining distribution systems. For safety and
practical reasons the collection tanks will not be attached to these concrete block RDP houses.
A multitank system that includes an elevated small tank for water to flush a toilet. Excess water will go to larger tanks that supply water for irrigation purposes. Low cost,
durability, practicality, and sustainability are key issues that will be evaluated. Following initial
evaluation in Ohio, the design team will return to South Africa and a prototype system will be
installed and evaluated on several RDP houses, and alternative housing approaches, that are
being studied by students and faculty at the UKZN. The reliability and durability of proposed
designs will be evaluated using a probabilistic risk assessment methodology. A comparative
evaluation of costs for each design will be conducted using a cost-benefit analysis.
Cost
:$9,998.00
Research Component
:P3 Challenge Area - Agriculture
Project IDs:
ID Code
:SU833508
Project type
:EPA Grant