Heritage Cases

INTRODUCTION The small harbours programme aims to drive the rejuvenation and upgrading of the small (fishing) harbours forming part of Operation Phakisa, to promote economic growth within the communities they serve. Currently, there are 13 proclaimed fishing harbours in the Western Cape. Within this programme six main project packages have been identified and The Department of Public Works (DPW) has established a Small Harbours Development Unit to implement and facilitate these packages which is already underway. In order to ensure the efficient rehabilitation of existing infrastructure and reinstatement of the original operational capabilities at each of the proclaimed harbours in the Western Cape, the 13 harbours were split into four packages. Of these four packages, Aurecon was awarded the Proclaimed Fishing Harbours Western Cape Work Package 3, which focused solely on the three west coast harbours at St Helena Bay, Laaiplek and Lambert’s Bay. Each of these harbours play a significant role in the local economy of the west coast, whether that be in the fishing or resource (in particular diamonds) sectors. In 1968, a channel was blasted to link the Berg River with St. Helena Bay, thus completing the formation of Laaiplek Harbour. The Laaiplek Harbour was developed to service the needs of the commercial, as well as subsistence fishing sectors. The harbour was proclaimed a fishing harbour in 1990 in terms of Section 26(1) of the Sea Fisheries Act (Act no. 12 of 1988). Laaiplek Harbour contains a main wharf with approximately 330 m quay length and a number of smaller jetties. The wharf consists of a wooden piled structure with timber plank decking and small bollards. Two boat ramp slipways with training walls are also present. Fishing vessels of up to 40 metres can be accommodated. PROPOSED HARBOUR MAINTENANCE AND REPAIR The maintenance and repair activities required at the harbour will include the following five aspects: - Concrete repair including sealing and grouting: Structural repair will be undertaken on the breakwaters and training walls. This will include resealing and grouting of concrete in order to stabilise the embedded sand layers. This is done to prevent the loss of sand fill from behind the sheetpile walls in these breakwaters, as is currently experienced. - Replacement of the timber quay: The upgrade of the timber quay will involve the removal of the existing quay and replaced with a new quay. It is anticipated that approximately 350 piles will be installed. The piles will be installed by initially drilling through the existing rip-rap/hard material layer and installing a steel circular tube (to maintain the drilled hole). The precast concrete circular pile will be guided through the steel sleeve and hammered/impacted down through the underlying material until the required bearing capacity is obtained. It is anticipated that the placement of approximately 230 m3 of concrete will be required in order to bind the rip-rap material together as to allow the drill bit to be able to drill through the hard material. It is expected that the placed concrete for the binding of the rip-rap material will cover a surface area of approximately 0.5m by 0.5m (area = 0.25m2) per pile. The precast concrete U-beams will be installed with the aid of a crane which will lower the precast beams into position alongside the installed piles and connected/fastened to the piles to create the initial structural frame (support structure). Installed on-top of the precast U-beams will be the precast concrete deck panels which will be supported by the U-beams and form the sub-deck of the quay. Along the quay line (berth line) precast concrete fender panels will be hung which will be concreted to the front row of piles and U-beams. Both the precast fender and deck panels will be placed using a crane. Once the precast sub-structure is installed the cast in-situ concrete topping will be poured on-top of the deck panels until the final design level of the quay. - Replacement of shore crane: The existing shear-leg / derrick crane on the timber quay will be replaced with a new knuckle crane. - Routine dredging of the harbour basin: Dredging of the harbour basin is a standard maintenance requirement for harbour operations, and should occur regularly to ensure the proper functioning of the harbour activities. This maintenance activity has been neglected in Laaiplek Harbour in recent years. It is has been determined that up to 9 600m3 of sediment will need to be dredged within the harbour basin to previously chartered depths, and future routine dredging activities will be necessary as a standard maintenance practice for the harbour. The most suitable location for the dredged sediment to be deposited is yet to be determined, but it is proposed that the dredged sediment be removed and deposited offshore in accordance with a specific Dredging and Dumping at Sea Maintenance Management Plan. - Removal of two sunken vessels: Two sunken vessels will need to be removed from the harbour. The South African Heritage Resources Agency (SAHRA) was contacted to provide assistance in determining if the removal of sunken vessels will require permitting in terms of the National Heritage Resources Act (Act no. 25 of 1999) (NHRA). Ms Lesa le Grange of SAHRA confirmed that the sunken vessels are modern therefore would not require a permit in terms of the NHRA for the removal thereof. The Listing Notices as defined in GN No. R.983, R.984 and R.985 of 4 December 2014 in terms of NEMA Environmental Impact Assessment Regulations, 2014 was examined and it appears that no listed activities are triggered for the removal of sunken vessels. An Environmental Management Specification (EM Specification) for the removal of sunken vessels was prepared by Aurecon’s Environmental Team, for the Specialist Service Provider who will be removing them. The EM Specification covers the standard requirements for controlling the impact of sunken vessel removal activities on the environment including the coastal environment. Due to the specialist nature of sunken vessel removal works, the planned approach is to request detailed Method Statements from the Specialist Service Providers during the tender process. These Method Statements will be evaluated with particular emphasis placed on compliance to the EM Specification and Safety Management Plans, which will include a plan for reuse, scraping and/or disposal.