Clanwilliam Dam trial blasting to ignite heightened construction activity
Department of Water and Sanitation (DWS) has carried out its first trial blasting at the Clanwilliam Dam construction site, triggering hard rock excavations and formally activating construction activity at the dam. The blasting which resulted to about 1253 m3 signifies the start of the construction work of raising the dam wall after some years of unprecedented delays.
Raising Clanwilliam Dam in the West Coast is one of the biggest Government infrastructure investments in the Western Cape, which involves raising the dam wall by 13 meters. The project will yield additional water for resource poor farmers of West Coast; creation of the much-needed jobs for the locals and generally, unlock the economy of the West Coast corridor.
The first blasting at left bank is a significant and noteworthy move, especially since the Clanwilliam project encountered many challenges associated with procuring service providers and materials. The success of this week's trial blast marked the beginning of a new era for the project as excavation activities are expected to unleash high-scale activity at the construction in the weeks to come.
Wisane Mavasa, DWS Spokesperson said prior to having a major blast, a trial blast had to be done first to check the following aspects:
- Determine parameters of future blasting activities in line with security of surrounding infrastructure (mainly the dam)
- To ensure that there are no damages to the dam, the dam remains safe and intact.
Prior to the execution of trial blasting, the blasting sub-contractor submitted blast designs to the Engineer and APP (Approved Professional Person) for approval. The APP (through consultation with a 3rd party Blasting Specialist) evaluated the designs and gave a go ahead, looking at aspects such as no blasting is allowed within 100m from the dam wall, unless it is controlled blasting.
Mavasa further stated that this week’s blasting was significant because it was the first blasting next to the dam which triggered hard rock excavations on the left bank. There were 116 holes drilled in preparation for the blasting activity, each hole had an average depth of 4m, with 920kg of explosives used for the blasting exercise. The total volume of hard rock excavations resulted from the blast is about 1253 m3.
With the blasting exercise, the hard excavations have been triggered on the left bank and regular blasting activities can be scheduled (almost monthly) through the same process as articulated above. All excavations remaining on the right and left bank are hard excavations and blasting will take place as approved and scheduled.
Blasting will continue until all hard excavations are completed on both banks, while other activities such as stripping of overburden at the quarry area, widening of the N7 are underway.
While DWS is aware of the delays in the implementation of the Clanwillliam Dam project over the years, it remains committed to completing the work within the revised timeframes, budgets, and specifications.
Enquiries:
Wisane Mavasa
Cell: 060 561 8935
