SA Water is currently undertaking a $3 million project aimed at restoring native vegetation across 450 hectares of land in the Mt Bold Reservoir and Clarendon Weir catchment, south of Adelaide. Planting has taken place over a five year period from 2005-6 to 2009-10.

Historically, the parcels of SA Water land included in this revegetation project had been managed by leasing them to local landholders for agriculture, predominantly cattle grazing with some hay cutting. Importantly, these parcels are within the water supply catchment that flows into Scott Creek, Clarendon Weir and Happy Valley Reservoir.

As part of the project, extensive weed control has been successfully undertaken. This work has sought to minimise as far as practicable potential exotic competition for the planted vegetation.

The revegetation areas have been planted with local native flora propagated from locally collected seed. Thus far, some 851,000 seedlings have been planted, supplemented by machine and hand-direct seeding. Replacement of seedlings lost to browsing animals will occur in 2010-11.

To encourage increased biodiversity, this project has also including planting understorey shrub and groundcover species to better mimic the ecology of neighbouring remnant bushland. Planting multiple sites over an extended timeframe has allowed the project team to investigate the merit of a range of available revegetation techniques. For instance, the project team will compare whether it is better to attempt the establishment of understorey species in the opening year of planting versus planting into four year old revegetation.In addition to planting, remnant bushland restoration has been undertaken on 107 hectares of former lease land, including a 20 hectare site managed on a weekly basis by volunteers through SA Water's partnership with Bush For Life.

Along with establishing a self-sustained native vegetation landscape, the project will:

• Control invasive noxious weeds on SA Water land and ecologically sensitive neighbouring sites
• Assist in improving the quality of run-off water from SA Water land
• Provide a buffer for the diversity of wildlife in neighbouring reserves
• Increase the absorption of carbon dioxide from the atmosphere through revegetation