Clogging of permeable pavers can occur if the pores become filled with fine silt.
In a silty environment (ie fine material, finer than sand) the pavers should be high pressure cleaned every 6 to 12 months.
The manufacturer guarantees that if this is undertaken, even in the silt or dirt laden environment, the pavers will hold the same flow rate for at least 15 years.
It should be noted that for Perth, the flow rate through the paver is already over 2.5 times that required by the one in 20 year, 5 minute duration storm. Therefore loss of some flow rate over many years will still allow the paver perform well in a severe storm.