Cranbrook-Toolbrunup Catchment Appraisal Report

The Cranbrook–Toolbrunup area covers about 81,395 hectares in the Pallinup North Stirling (and part Kent-Frankland) sub-region, on the South Coast. It occupies 46,290 ha of the Tambellup Shire; 33,973 ha of Cranbrook Shire; about 729 ha of Gnowangerup Shire; and 403 ha of Broomehill Shire. The town of Cranbrook is included and Tambellup is directly adjacent to the west.

Geology is dominated by the granite and gneiss of the Yilgarn Craton. Hydrology is strongly influenced by the broad and often stagnant flats that are found mostly in the north. The soils are dominated by deep and shallow sandy duplexes, while gravelly soils with saline wet soils are also common.

Poorly drained sandy duplex, sandy duplex and gravel slopes and ridges are the three most widespread land management units.

Areas of current degradation and hydrological risk (rising watertables up to 2 m below the surface) are estimated at 9,017 ha (11%) with 28,400 ha facing potential risk.

Other land degradation risks include susceptibility to soil acidity (54% of catchment) and wind erosion (40%). About 48 km of sealed road, 65 km of unsealed roads and 23 km of railway line faces damage from high watertables.

Strategies from the best available information to address reduction of recharge and land degradation, as well as protection of remnant vegetation have been included.

Publication Date: July 2002 Author: Tim Overheu Document Type: Booklet - .pdf 1.4mb