WHAT WE DO

GRC Hydro is a hydrology and water engineering firm based in Sydney, Australia.

We offer specialist knowledge and expertise in the fields of hydrology, hydraulics and floodplain management.

We work with government and private clients to fully understand their flooding issues and help them to plan, mitigate and manage them effectively.

Our technical services consist primarily of Flood Impact and Risk Assessments (FIRA), floodplain management studies and flood impact assessments, while also including stormwater drainage and on-site detention design, hydrological studies for infrastructure, and post-event data collection.
OUR SERVICES

FLOOD STUDIES
AND FIRA

Flood Studies are undertaken to understand an area's local flooding regime through the modelling of historical and design flood events.

These studies establish an area's design flood behaviour and are the first stage in managing an area's flood risk

GRC Hydro is currently undertaking a number of flood studies around the state.
FLOOD EMERGENCY RESPONSE PLANS

Flood response plans are commonly required for new development affected by flooding.

These plans set out the procedure for evacuation, or sheltering, from a flood.

GRC Hydro have prepared plans for a number of schools, aged care, residential and other developments across Australia.
FLOODPLAIN RISK MANAGEMENT
STUDIES AND PLANS

The NSW Government assists Councils that contain flood-liable areas to undertake Floodplain Risk Management Studies and Plans.

These studies seek to fully understand the area's flood risk, and build on the area's Flood Study.

They describe the full range of effects of flooding in detail and develop a plan of floodplain risk mitigation measures to be carried out.

DA REPORTS
FOR COUNCIL

Development that is proposed in a flood-liable area is required to be designed and constructed in a way that does not adversely impact the local flooding regime.

GRC Hydro is able to undertake a localised flood study to determine your development's impact and devise ways to lessen the impact on design flood events, as part of the development application process

We also provide flood certificates describing a location's flood risk in relation to local legislation.
LAND AND ENVIRONMENT COURT
FLOOD EXPERTS

GRC Hydro is able to provide expert witnesses for flooding related Land and Environment Court proceedings.

GRC Hydro personnel have extensive experience in this space and are able to offer their professional understanding and modelling capabilities to both public and private clients.

PLANNING PROPOSALS
SSDA, AND REZONING

State-significant projects and rezoning of land require a flood assessment that meets both local and state policy requirements.

GRC Hydro have carried out flood assessment for multiple residential subdivision projects across NSW and for large-scale mixed-use developments in Sydney. Clients for rezoning projects include Canada Bay Council, Parramatta Council and multiple projects for NSW DPHI.
SSDA AND PLANNING PROPOSALS

In addition to our local knowledge and expertise, we are experts in the preparation of Flood Impact and Risk Assessments (FIRA) required by the NSW Department of Planning, Housing and Infrastructure (DPHI) as part of rezoning and State Significant Development (SSD) applications, routinely completing these studies for a range of development types and clients. Project experience across SSD and Planning Proposals includes flood assessments for:
-Five Dock Rezoning and Parramatta Road Corridor Urban Transformation Strategy Stage 2 (Canada Bay Council)
-Forest Lodge, Prince Alfred Park Rezoning (City of Sydney)
-Green Square Sites 7, 17 and 18 (Mirvac)
-Gosford City Centre Flooding and Stormwater Advice and Crows Nest State-lead Rezoning (NSW DPHI)
-78 Hughes Avenue, Ermington (Knight Frank)
-60 Union Street Pyrmont and Churchill Ave Strathfield (Lighthouse Project Group)
-Kiaora Road Double Bay and St Georges Crescent Drummoyne (Dare Property Group)

FLOOD EMERGENCY RESPONSE PLANS

GRC Hydro provide expertise and experience in preparing Flood Emergency Response Plans (FERPs) for existing and new development. FERPs are commonly required by local and state governments to ensure that building and site occupants can safely respond to a flood, with consideration for rare to extreme floods well above the design flood. GRC understand the need to scale a FERP to the scale of development and the nature of flood risk, having prepared plans for a range of sites. Previous projects include sites at Camperdown (University of Sydney), Richmond, Windsor, Ultimo, Marrickville, Waterloo, Chipping Norton and Warwick Farm.

OUR PROJECTS

RECENT WORK FROM GRC HYDRO

Parramatta Road corridor in Sydney's west
PRCUTS STAGE 2
CLIENT: CANADA BAY COUNCIL

GRC Hydro prepared a flood assessment of proposed rezoning along Parramatta Road, as part of the Parramatta Road Corridor Urban Transformation Strategy (PRCUTS) planning proposal. The corridor contains area of overland flow and creek flooding. Rezoning is being undertaken in parrallel with construction of the Sydney Metro stations at Burwood and Five Dock. The project progressed to public exhibition in July 2026.
Green Square, Sydney (GRC Hydro)
GREEN SQUARE MIXED-USE DEVELOPMENT
CLIENT: MIRVAC

GRC Hydro is undertaking two Flood Impact and Risk Assessments (FIRA) for new development at Green Square, prepared as an SSDA for the NSW HDA. Development consists of nine new high-rise buildings in close-proximity to Green Square station. Flooding in the area includes overland flow flooding, in the Alexandra Canal catchment. GRC Hydro have updated City of Sydney flood modelling to use the latest ARR climate change factors.
Canberra Light Rail Concept (Canberra Times)
CANBERRA LIGHT RAIL PROJECT
CLIENT: ACT GOVERNMENT/CAPITAL METRO/SMEC

The project involves flood modelling as part of the detailed design stage of the proposed Canberra Light Rail. Hydrologic and hydraulic analysis using a WBNM/TUFLOW modelling system was undertaken in order to assess criteria including depth over rail and flood impacts in design flood events. The modelling system provides high detail flood information over a large area.
Barangaroo (GRC Hydro)
HICKSON ROAD, BARANGAROO, FLOOD MODELLING AND DRAINAGE DESIGN
CLIENT: BARANGAROO DELIVERY AUTHORITY, WARREN SMITH AND PARTNERS

GRC Hydro is currently undertaking a hydraulic investigation for Hickson Road, inclusive of a proposed subterranean train station at Barangaroo. This is being executed by using a TUFLOW rainfall on grid model. The study’s main outcome will be the design of a trunk stormwater drainage system considering various constraints.
CONTACT US

Zac Richards
[email protected]
+61 432 477 036


Level 20, 66 Goulburn Street
Sydney NSW 2000
GRC Hydro Pty Ltd
Level 20, 66 Goulburn St,
Sydney, NSW 2000, Australia
ABN: 71 617 368 331