Megarritys Bridge facts for kids

Megarritys Bridge is an important bridge in New South Wales, Australia. It crosses Megarritys Creek near the Warragamba Dam. This bridge is located in the Wollondilly Shire, in the south-western part of Sydney. It was built by the Metropolitan Water, Sewerage and Drainage Board, which is now known as Sydney Water. The bridge is owned by Water NSW, a government agency. It was added to the New South Wales State Heritage Register on 18 November 1999 because of its special history and design.

The Story of Megarritys Bridge

Megarritys Bridge is a concrete arch bridge that spans Megarritys Creek. It was built to be a very important link for the Warragamba Emergency Scheme. This scheme was a big project to make sure Sydney had enough water.

Why the Bridge Was Built

The bridge was first designed to carry a very large water pipe, about 2.7 metres (106 inches) wide, from Warragamba Dam. However, for the Emergency Scheme, it carried a smaller pipe, about 1.2 metres (48 inches) wide. This pipe moved water from the weir to Prospect Reservoir. This shows how crucial the bridge was for moving water around.

How Megarritys Bridge Was Built

The way Megarritys Bridge was built was quite special for its time. The builders used a unique method for its arch shape.

Innovative Building Techniques

The construction used a special "formwork" design. This is like a mould that holds the concrete in place while it dries. What was really new was that they used tubular steel scaffolding for this mould. It is believed that this was the first time this material was used in New South Wales for such a heavy-duty job. This made the construction process very strong and efficient.

Changes Over Time

The bridge looks mostly the same as it was first designed. However, in 1989, its height was increased by 5.1 metres (about 16.7 feet). This change was part of flood prevention work. It helped the bridge handle large amounts of water during floods.

Why Megarritys Bridge is Special

Megarritys Bridge is considered very important for its history and engineering. It was officially listed on the New South Wales State Heritage Register on 18 November 1999.

A Unique Engineering Design

One reason the bridge is special is its "bow string" arch design. This is different from the more common "decked" arch bridges. At the time it was built, it was one of the largest concrete arch bridges in New South Wales. Its unique design makes it a rare example of engineering heritage. It also played a vital role in carrying the main Warragamba pipeline across Megarritys Creek.