An STS taxpayer can choose to claim deductions under either the STS rules or the UCA rules for certain depreciating assets used in the course of carrying on a business of primary production. The choice is available for water facilities and for depreciating assets relating to landcare operations, electricity connections and phone lines.
You can choose to claim your deductions under the STS rules or the UCA rules for each depreciating asset. Once you have made the choice, it cannot be changed.