SESL was engaged by Googong Township P/L to conduct a soil survey for the new Googong Township development in Googong NSW. CIC Australia is currently developing Googong North, the first neighbourhood of Googong Township, and this assessment was conducted as part of the Stage 6 development.
The survey was conducted to assist in the beneficial reuse of materials generated from bulk earthworks onsite. SESL was also engaged to review the existing trees installed onsite, and provide recommendations to improve trees establishment onsite.
SESL conducted the following assessment:
Characterise the stripped topsoil and subsoil as well as granite rocks recovered onsite, and determine its potential use for landscape purposes.
Field observation and laboratory assessment was conducted to identify any constraints within the soil quality in relation to supporting healthy tree and plant growth.
Site assessment was also conducted to characterise the soil profile on site, as well as review the current soil reconstruction and planting methods for urban trees.
The assessment discovered that the site topsoil, subsoil as well as its abundance of granite rocks can be successfully ameliorated and reused for landscape purposes across the site.
This favorable outcome leads to sustainable use of material recovered from site, and a cost effective strategy as the amount of imported soil that is required for the site can be significantly reduced. Therefore, SESL developed a number of site-specific soil specifications based on utilising the site material, that included specific soil components and ameliorations required to enable the establishment of the selected tree species for the landscape development.
The assessment also identified room for improvements for the installation of trees onsite. SESL prescribed a range of recommendations that will assist the establishment of the urban trees, by increasing available soil volume and root space. An improved soil profile reconstruction strategy that maximizes the potential of each soil layer (available nutrients from topsoil, good structure and drainage from subsoil and subgrade) was also provided to ensure the new trees planted will establish successfully. SESL also recommended some remedial options to assist with existing trees onsite, including improving drainage, amending irrigation, and fertiliser regime.