I have some Frequencys for northam if that helps.For Police try:468.5250,468.7250,468.8750,468.9000 and 469.3250.SES:468.6000 and 468.6500.WA TourismEventscorp:77.9750 otherwise try search on day 1 of the avon.
Westnet Rail usually have a flagman on the crossings in the Valley and keep them up to date with train running info, so try Eastern Control on 419.075, 419.1, 418.4, 419.05