Harrison Park is located within the Shellharbour city centre and was identified as part of the 2020/21 Capital works programs for the area. The City Pond in Harrison Park is one of the built wetlands in the Shellharbour precinct.
The project aimed to improve water circulation within the basin and ultimately improve the overall water quality and therefore the surrounding environment for flora and fauna.
The scope of works included draining the basin, removal of rubbish and weed material, demolition of existing drainage structures and installation of a new outlet to allow the basin to be drained by gravity, extension of selected inlet pipes including a small amount of tree removal to allow for the installation of new circulation trenches and earthworks to improve landscaping of the area.
Donnelley Civil now provide an inhouse concrete service with a concrete pump and skilled team in forming and concrete works. The use of the concrete line pump in place of wheelbarrows/shovels minimised damage to the environment and was quick and accurate. Works included installing ballast base and pipes and headwalls for the outlets. A significant change in scope of the pipes, headwalls and pits construction and demolition was required by Council and Donnelley Civil were able to implement with an amended construction program and variations to meet the outcomes.
Donnelley Civil identified the opportunity to develop a mix with DGB (Densely Graded Base) and the silt being removed from the watercourse to enable the reuse of 99% of material on site and provided the Client with a substantial cost saving. Over 500t of DGB was required to mix with the silt to produce a suitable material.
Landscaping services on the project included mulching, top soil dressing and hydro seeding. The DGB and silt mix enabled use of material on site to provide a landscaped bank and spreading of material to create a useable seating area. Independent Enviro audit completed – No issues – Note the ducklings now on site in addition to Plover babies. This is a very good sign that our environmental mitigation strategies are working well.
Unexpected variations to the job included 2 dumped cars in the waterway and a multitude of plastic water bottles. All removed safely and with minimal environmental impact. The site lost only 2 days due to severe storms and flooding.