Our Projects / Retention Basins / Jerralong Basin Retention Basins Jerralong Basin Client: Blacktown City Council Scope: Dewatering and cleaning out of existing dams Bulk earthworks – Cut & fill works with GPS equipment Network of Bioretention basins with spillways and access tracks Installation of drainage system with headwall outlets and sandstone rip rap and dissipaters Install subsoil drainage and pits Installation of 3 GPT pits up to 6m deep including associated drainage lines Installation of Landscaping, fencing and signage around bioretention basins