The Western Australian Constitution was, for most of its history, different from the Australian Constitution because a referendum is not required to change any part of it. Instead it can be amended by State Parliament if both Houses agree by an absolute majority.
However, in 1978 State Parliament amended the Constitution Act 1889 so that some of its provisions could only be amended by a State referendum. From that point on, major components of the WA Constitution became strongly entrenched. This was the most important constitutional amendment since 1905 and required that a referendum be held to:
Abolish or alter the office of the Governor;
Abolish or reduce the number of the Members of Legislative Council or Legislative Assembly;
Provide that either House has members other than members chosen directly by the people.
To date no such referendum has been proposed
The Constitution was amended again in 1989 to extend the life of any parliament from a maximum of three years to a maximum of four years, an amendment that did not come under the referendum provision. That change was passed by both Houses and became law. By comparison, the Commonwealth could not instigate such a change without a referendum.
Despite many changes in the State and the role of government since 1890, the constitutional structure of Western Australia has remained largely unchanged.