storm water management in accra, ghana - presentation
TRANSCRIPT
Storm water management
in Accra, Ghana
Heather Troutman Asiedu-Danquah
Urban water cycleProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning
Summer semester2015
June 16, 2015
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Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 2
Table of content
General overview
Projects
Overview of the study area Climate and precipitation Storm water drainage Flood situation
Urban env’tal sanitation project-odaw drainage improvement-Korle lagoon ecological restoration project
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 3
Climate and precipitation data
Mean annual rainfall in Ghana for the period 1981 - 2010Source: Logah et. al. (2013)
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 4
Climate and precipitation data
Source: http://people.eku.edu/davisb/Africa/Ch5notes.htm
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning
Climate and precipitation data
Source:
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Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 6
Climate and precipitation data - Return Periods
One day rainfall occurrences
June 27, 1960 98 mm
June 22, 1973 175 mm
July 14, 1991 157 mm
June 9, 2002 123mm
October 25, 2011157mm
Most Extreme one day rainfall occurrence
July 4, 1995 – 244mm
Source: https://www.modernghana.com/news/223779/1/are-the-municipal-solid-waste-management-practices.html
Source: Adopted from Okyere, Yacouba & Gilgenbach (2012)
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning
Storm water drainage
Source: Adank et. al (2011)
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Avg. precipitation756 mm/year
Accra area1,261 km2
Avg. Storm water9.5 million m3/year
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 8
Linkages b/n hydrological, economical and political context of
flood in Accra
Source: Adopted from Okyere, Yacouba & Gilgenbach (2012)
Natural factors human factors
floods
impacts
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 9
Urbanisation & sanitation
Source: Adank et. al (2011)
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 10
flood situationJune 03, 2015
http://www.ghanaweb.com/GhanaHomePage/NewsArchive/artikel.php?ID=362491&gallery=0&VOLGNR=1
Overview of event
12 hours of rainfall
263 mm
About 35 settlements affected
150 people killed
About 9,200 people affected
http://graphic.com.gh/news/general-news/44408-annual-floods-in-accra-an-engineering-failure.html
Response
Clear debris from recent floods, as well on de-silting of choked drains
Clearing all structures in waterways
Source: UN
CT G
hana, 2015
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 11
flood situationJune 03, 2015
Actors
NADMOUNITED NATIONSInter-Agency Working Group for Emergencies (IAWGE)UNICEFWHOThe Ghana Red Cross
Source: UNCT Ghana, 2015
Suggested Long term solutions
120 km of storm drains along the major river basins
To construct water retention reservoirs
Addressing issues of waste collection and disposal
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning
Common response
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Source: http://citifmonline.com/wp-content/uploads/2015/06/dysilting-of-odaw-river-2.jpg
Odaw river desilting
Source: http://citifmonline.com/wp-content/uploads/2015/06/dysilting-of-odaw-river-6.jpg
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 13
Source: (world bank report)
Projects
Phase 1: 1996 – 2004Dredging and lining of primary and secondary
storm drains
Phase 2: 2004 – 2007Lagoon restoration
Erosion controlConstruction of small
bridges
Urban Environmental Sanitation Project
Legal Impetus
Ghana Environmental Sanitation Policy
Ghana Poverty Reduction Strategy
United Nations Millennium Development Goals
#6: combating HIV/AIDS, malaria and other diseases
#7: ensuring environmnetal sustainability
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 14
Uesp - Odaw drainage improvement
Objective: “To alleviate flooding, the profile of the channel had to be reconstructed into a rectangular/trapezoidal shape,
so it could carry a 1:25 years flood”.
Source: (Bam International, 2014)
Under the budget of Ghana’s Urban Environmental Sanitation
Project
The Odaw Drain is the main outflow channel for Accra’s storm water drainage network in Accra.
Scope of workConstruction of a concrete-lined
channel.Length: 3.4 kilometres
Width: 23 metres Depth: 5 metres
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 15
Source: (Bam International, 2014)
Urban Environmental Sanitation Project
Uesp - Odaw drainage improvement
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 16
Impacts on Lagoons
Source: (PMI, n.d)
Pollution
About 90, 000 people living around the catchment of the lagoon
Total surface area is about 0.6 km2 and drains a total catchment area of about 400km2
The Odaw river enters the Korle lagoon and has a large concentration of industrial wastes
Korle lagoon ecological restoration project
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 17
UESPRound 2(KLERP)
Source: (PMI, n.d)
Objective: to improve Accra’s drainage, flooding and sanitation problems
Ensuring good flood waterconveyance to the sea
Implement the sewer pumpstation and offshore outfall pipeline.
4 phased project
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 18
Source: (PMI, n.d)
Phase 1
Dredging of the lagoon
Creation of storm water canals
Removal of swamps to reduce flooding
Creation of green areas
Construction of an inceptor
Construction of a pump station
Outfall installation works
Infrastructure works
Sediment removal and re- dredgingof the lagoons
Sediment removal in the canals &drains
Fencing & beautification works
Design, supervise and construct bulkservices including roads, water, sewer,storm water, drainage
To execute the required EnvironmentalImpact Assessment.
Phase 2 Phase 3 Phase 4
UESPRound 2(KLERP)
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 19
Recommendations and conclusions
Waste management solutions
Urban development solutions – creating sustainable housing
Covered drainage with pv cells
Construction of retention reserviors
Heather Troutman Asiedu-Danquah
Urban water cyclesProf. dr.-ing. wolfgang dickhaut
Resource efficiency in architecture and planning 20
Thank you!!