By law, swimming and spa pools containing water more than 30cm deep must have effective safety barriers that restrict access by young children.
This includes portable pools.
You can pick up a copy of DMIRS' brochure from the Shire of Three Springs Admin Centre, or download a copy from:
https://www.commerce.wa.gov.au/sites/default/files/atoms/files/rules_for_portable_pools_0.pdf