RESILIENT CITIES 2011 EKO ATLANTIC CITY PROJECT AS A CLIMATE CHANGE ADAPTATION STRATEGY Presentation by Prince Adesegun Oniru ( Honourable Commissioner, Lagos State Ministry of Waterfront Infrastructure Development)
SHORELINE PROTECTION PROJECT BAR BEACH VICTORIA ISLAND LAGOS Introduction and review of Engineering Works executed from June 2007
SHORELINE PROTECTION WORKS What was the condition of Bar Beach immediately prior to the award of the contract in December 2005?
Storm event 0ctober 31 st 2005 The storm destroyed large sections of the nearside carriageway of Ahmadu Bello Way Sand in excess of 400mm thick was deposited on both sides of the carriageway rendering it impassable for motor vehicles Sea water entered the compounds and ground floor of adjacent dwellings
Ocean surge floods the beach
Encroachment of sea water
Flooding of road
sand deposits on carriageway
Erosion of beach front (west)
Erosion of beach front (east)
What is the Extent of the Erosion? Studies have determined that: Between 8 14m of beach-front is eroded annually along Bar Beach 2,800m 3 (average) of sand eroded daily
Introduction and Brief History Bar Beach, once a popular and prestigious beachfront, was the a poor reflection of its former glory Severe coastal erosion has removed in excess of 2 km of beach front and at times the adjacent road; resulting in acute disruption to traffic flow and flooding of properties The erosion is a direct result of the construction of rock moles between 1908-1912; to protect the harbour access The moles interrupted the natural Littoral Drift along the African West Coast which transports and deposits sand along the beaches of Western Nigeria Since the early 1950 s to date in excess of US$250 million expended in regular sand replenishment to restore the beach, without providing a permanent solution
Search for a Permanent Solution Developers Energyx submit a privately financed proposal for a permanent solution in April 2004 subject to concluding further technical and financial reviews Energyx proposal reviewed with other alternative proposals by a joint Lagos State & Federal Government commission on 1st September 2004 Review continues into 2005 Mr. President authorises Lagos State Government to implement an agreement with a Developer for a Permanent Solution in August 2005
The Engineering Works Commence 12 th December 2005 Lagos State Government awarded a Contract to Hitech Construction to perform Shoreline Protection Works. 1,000m length of the most severely eroded section of the beach to be protected.
Cross section of shoreline protection +3.905 +4.00 ROCK (300-1000 Kg) +3.00 ROAD SAND ARTIFICIAL SLOP ARTIFICIAL SANDFILLING SAND NATURAL SLOP ROCK (300-1000 Kg) Drawing Title: SOO1 SCALE 1: 100 DATE 15/05 /06 DRAWN JIHAD KAMEL (S.M) CHECKED AD de BEST (P.M) LEGEND 300-1000kg 10-100kg SAND XBLOC Project: Drawing Title: SHORELINE PROTECTION TYPICAL CROSS SECTION BAR BEACH PROJECT VICTORIA ISLAND Engineer HITECH CONSTRUCTION CO. LTD. 8th Floor,1682 Sanusi Fafunwa Street Victoria Island,Lagos (234) 1 2623351 Fax: (234) 1 2611307 STRUCTURAL CIVIL ROAD ENGINEERS
Summary of Construction Process Sand Replenishment Contour Sand to required profile Lay Geo-Textile matting to beach-front Place first Layer of Rock (10 60kg) 300mm thick Place second Layer of Rock (300 1000kg) 700mm thick Place x-blocs Further compacted sand layer on beach-top Lay Geo-Textile matting to beach-top Place Layers of Rock on beach-top to rear of x-blocs Cast 150mm thick concrete bed on remaining beach-top Form roadside drain and beam
SHORELINE PROTECTION WORKS COMMENCEMENT OF WORK.
Turning of Sod Celebration 5 th February 2006 Governor s speech
Turning of sod celebration inspecting the yard based model
Delivery of first x-bloc mould
Placing concrete in x-bloc moulds
First casting concrete x-bloc s 20th January 2006
Aerial view of pre-cast yard
x-bloc storage area
Concrete x-bloc production A total of 5,000 x-blocs were cast for the project over a period of 6 months Making use of chemical additives to the concrete mix maximum use of the steel mould was achieved with 2 castings every 24 hours from each mould utilising 2 teams of operatives working in shifts Frequent tests were made to each batch of concrete and each x-bloc to insure adherence to specification and strength attainment before transfer to the stock area and final location
SHORELINE PROTECTION WORKS QUALITY CONTROL
Taking concrete samples for laboratory testing
Storing concrete test cubes
Concrete slump test prior to casting
Crushing test cubes to insure design compliance in compressive testing
Taking core samples for testing
Crushing core samples to determine tensile strength compliance
Site testing of concrete
Dial indicating test result
Testing compacted sand for moisture content and degree of compaction
Testing sand quality
SHORELINE PROTECTION WORKS SITE WORK
Delivery of sand to beach-front to replenish and widen beach
Compaction of sand with dozer roller and water-tanker
Surveyor establishing levels on beach-front and shoreline
Establishing final profile on beach-front
Jointing of geo-textile material in yard to form large sheets
Placing weights on matting to insure anchorage on sea-bed
Forming initial rock barrier to waves
Aerial view of rock barrier to waves
Placing geo-textile on sea bed
Timing is critical the sea is unforgiving
Placing geo-textile to slope
Stretching geo-textile up slope and over beach-top
Placing first rock layer to base
Placing first row of x-blocs
Placing rock to sloping face
Placing x-blocs to slope
View at toe of x-blocs
Completed section of beach-front showing interlocking of x-bloc s and 10m of rock extending seaward
Levelling sand to beach top
Laying geo-textile to beach top
Setting out steel forms for concrete slab on beach top
Compacting concrete with vibrator
Placing and levelling concrete in slab
Protecting concrete slab from rainfall
Trowelling surface of concrete
Treating concrete surface with curing agent
Placing final rock boulders
Placing pre-cast concrete beams
Finished beach top / walkway
SHORELINE PROTECTION WORKS VIEWS OF THE FINISHED STRUCTURE
Elevation ocean side
Elevation beach top
Elevation roadside
Aerial view 1
Aerial view 2
A TIMELY INTERVENTION The Shoreline Protection Project was awarded on 12 th December 2005 for completion on 12 th December 2006 Between 16 th -18 th November 2006 Bar Beach was subjected to the worst storm on record for the previous 10 years
THE POTENTIAL FOR A DEVASTATING FLOOD Sea levels were elevated 1.5m above the average for the time of year It was estimated that during the peak of the storm the length of the structure was bombarded by approximately 5,000 cubic metres of sea water every 10 seconds
FACT It is rarely appreciated that the junction of Ahmadu Bello Way and Akin Adesola road a point along Bar Beach protected by the Shoreline Protection Works is actually THE HIGHEST POINT OF ELEVATION IN VICTORIA ISLAND The opposite end of Akin Adesola (Falomo Bridge ramp) is at an elevation 2m lower
A DISASTER AVERTED Given the severely depleted condition of Bar Beach in November 2005 (refer to slides 3 to 8) there was no present barrier to any storm condition whatsoever prior to the construction of the Shoreline Protection Works. The exceptional ocean surge of November 2006 would have engulfed a greater part of Victoria Island dumping 1,800,000 tons of sea water EVERY HOUR over the length of the beach during the peak of the storm.
SHORELINE PROTECTION WORKS CONDITIONS RECORDED DURING THE STORM OF 16 th 18 th NOVEMBER 2006
High elevated wave
The destructive power of the waves
Wave breaking at toe of structure
overspray crashing on the walkway
overspray repelled by beam
Yet still the road remains dry
SHORELINE PROTECTION PROJECT RECOGNITION AND AWARDS
CED FORUM AWARD 2006 AWARD OF EXCELLENCE
The West African Direct Marketing Award 2006 West Africa s Best Shoreline Project
SHORELINE PROTECTION PROJECT Mission accomplished The whole works were officially completed on 4 th December 2006 8 days ahead of schedule
EKO ATLANTIC CITY The protection continues
EKO Atlantic City development
The overall area to be reclaimed is 820 Hectares or 8,200,00m2. The total length of the Development is 6,500m and on average 1,260m wide. To the Southern Boundary is the main Revetment 6,500m in length. To the East Boundary is a Revetment of 920m in length and incorporates a large Marina with access to the sea. To the Northern Boundary is the existing Victoria Island and more specifically the existing Ahmadu Bello Way highway which is planned to be extended to an 8 lane highway known as Coastal Road under proposed Government planning. Incorporated in the Development will be central waterway 30m wide providing water transport facilities connecting 3 Marinas.
Other facilities comprise: An international standard road network Surface water drainage Dedicated electrical power generation plant and underground distribution. Water Supply, treatment and distribution mains Sewage collection mains leading to a modern plant. A network of service ducts to provide IT services. Post construction maintenance and management of the facility.
EKO ATLANTIC CITY LAY OUT
DREDGING OPERATIONS FOR EKO ATLANTIC CITY 93
SANDFILLED PORTION OF EKO ATLANTIC CITY 94
Work Done so far
Where we are Today
Award by Clinton Climate Initiative
THANK YOU EKO ONI BAJE.