Provision of Topographic and Bathymetric Survey of the East Trinity Environmental Reserve

The Department of Environment and Science (DES) through the Science and Technology Division, require the provision of current topographic and bathymetric data sets and associated reports and digital data for the East Trinity Environmental Reserve, Cairns.

The 750 ha East Trinity site (Cairns) was converted into a cane farm by Colonial Sugar Refineries (CSR) c. 1972. This included construction of a bund wall around the site to prevent inundation by the tides, drains to reduce groundwater levels, floodgates to allow for the flow of storm water through the property, and land levelling to develop flat arable land. These activities exposed significant areas of potential acid sulfate soils (PASS) to air, resulting in acidification of soil, groundwater and waterways. The East Trinity Acid Sulfate Soil remediation project (ASSRP) commenced in 2001 with the aim to remediate and stabilise acid sulfate soils and water quality on the site. The project used an innovative remediation technique known as Lime Assisted Tidal Exchange (LATE). LATE involves controlled inundation of low-lying parts of the site with saltwater augmented by selected lime treatment of soil and water.

The success of the LATE method led to active water treatment ceasing in 2017. In order to assess current site conditions and to inform an analysis of future management options and potential impacts, the Department of Environment and Science (DES), through the Science and Technology Division, require current topographic and bathymetric data sets and associated reports, including digital data, for the East Trinity Environmental Reserve.

Further background information and complete requirements are outlined in Schedule 1 of the attached ‘Contract Details’.

17/12/2019 - DES19291 Addendum 1_Site Visit Details

15/01/2020 - DES19291 Addendum 2_Response to Queries from Site Visit and Additional Information (attachments)