Porters Creek Dam Remediation project
The Porters Creek Dam Remediation project was the preparation and placement of approximately 4,000 cubic metres of concrete along the downstream face of the dam along with associated outlet and access works.
Director of Shoalhaven Water, Carmel Krogh said the existing Porters Creek Dam had been constructed in 1968 and was currently in need of remediation works.
“Porters Creek dam is a key water supply source for the southern Shoalhaven area, particularly during the peak summer season,” said Ms Krogh.
Shoalhaven Water has officially opened the upgraded Porters Creek Dam, half a century after the initial dam construction in 1967.
The dam provides approximately 30% of Southern Shoalhaven’s drinking water supply and has a reservoir capacity of 1,900 mega litres.
Carmel Krogh, Director Shoalhaven Water, is proud of the outcomes of the upgrade from a number of perspectives, saying “The dam upgrade is a major milestone for Shoalhaven Water. It will ensure we have adequate water supply for the southern Shoalhaven in the future. The dam was built on time and under budget and included 25,000 man hours to upgrade.”
Ms Krogh was particularly pleased that the new project provided some fascinating linkages with the original dam. “The original dam was constructed in 1967 by Shoalhaven Shire Council and was designed and supervised by the engineering firm Gutteridge Haskins and Davy (GHD). A young 17 year old named Laurie Andrew started his working life at that time as a trainee surveyor on that dam project. Fifty years later GHD designed the upgrade and that same Laurie Andrew works for Shoalhaven City Council and acted as Council’s site supervisor for the upgrade”.
The original dam consisted of a 17 metre high by 139 metre long post-tensioned concrete gravity section with an overflow spillway integral with the crest. The upgrade commenced in March 2016 and eight months later, a new dam wall involved the construction of 4,500m3 of concrete gravity buttress and stilling basin has been constructed.
The upgrade of the dam was in response to meet safety requirements, to ensure longevity of the dam structure and consequently meet the future water supply demands of the Milton and Ulladulla communities.
The upgrade also included the 3.6km of Porters Creed Rd sealed from the Princes Hwy to Graydon Pointer Rd.
Porter Creek Dam Facts
• Provides 30% of Southern Shoalhaven’s drinking water supply.
• Reservoir capacity 1900 mega litres.
• Shoalhaven City Council commissioned GHD Pty Ltd to design modifications to the dam and a contract for construction was awarded to Leed Engineering and Construction Pty Ltd in 2015.
• 4,500m3 of concrete was batched and poured on site to form the new dam wall.
• 3.6km of Porters Creed Rd sealed from the Princes Hwy to Graydon Pointer Rd.
• 25,000 man hours.
• Cost $8.5M (within the $10M budget).
“Due to the critical nature of the dam as a supply source and the long term risks associated with the post tensioning cables Council decided to proceed with the upgrading of the dam.”
“Council’s appointed contractors, Leed Engineering have an excellent reputation for delivering projects on time and working in a collaborative way with clients, stakeholders and the wider community.”
Published Nov 2015 – updated Feb 2017