The Geographe Catchment is bounded by the Darling Range, the Whicher Range and the Leeuwin-Naturaliste Ridge. Below these ridges is an extensive coastal plain, the southernmost part of the Swan Coastal Plain, extending south and west to Dunsborough.
The escarpments are of mixed origins and include the granite based Darling Range and Leeuwin-Naturaliste Ridge, and the sedimentary based Whicher Range. The soils of the coastal plain are predominantly sandy-loam surfaced soils of mixed origin.
Three prominent land systems have been identified by the Department of Agriculture (Tille et al. 1990) in the Geographe Catchment area, including the Quindalup Coast, Ludlow Plain and Abba Plain areas.