The report said Murray would have a population of 164,000, while Mandurah would have 148,000.
Job numbers are also likely to increase, with 18000 in Ravenswood and a further 7000 in Mandurah by 2050.
The report suggests measures to help the Peel region deal with population growth, such as a better transport system, an extension of road networks and an increase in housing density.
The report was considered by Mandurah City councillors at their meeting last week.
Cr Caroline Knight said the document would have a significant impact on the region.
She said it was important to remember that while there was a clear need to increase density, it must not come at the cost of amenity for residents.
�The public has a right to expect the POS requirements established back in the 1950s when block size was much larger, be re-examined,�� she said.
�I would like to see that addressed in the recommendation.�
The City of Mandurah is expected to lodge a submission on the report and one in conjunction with the Shire of Murray and the City of Rockingham.