IAH – June Tech Talk

Presented by: David Harris

Produced by: IAH NSW

Date: Tuesday 10 June 2025
Time: 17:30 for an 18:00 start
Where: WSP Office – Level 27
Online: Teams link

Abstract:

Urban estuaries represent highly dynamic and intricate environmental systems, characterized by the confluence and mixing of freshwater from riverine and groundwater sources with saline tidal inflows. This complexity is further amplified by episodic, and often contaminant-laden, stormwater runoff, a hallmark of urban landscapes. Each of these contributing water sources possesses distinct chemical signatures; however, these signatures frequently overlap, particularly in environments subjected to extensive anthropogenic pressures. The task of isolating and quantifying the groundwater component, often referred to as Submarine Groundwater Discharge (SGD) when it enters estuaries, is of paramount importance to quantifying catchment dynamics. Understanding SGD is critical for accurately assessing nutrient budgets, delineating contaminant transport pathways, and evaluating the overall ecological health and resilience of estuarine ecosystems. The process of urbanization introduces a wide array of anthropogenic contaminants into the hydrological cycle, profoundly altering natural geochemical baselines and making the differentiation of water sources a formidable challenge. The very nature of urban development, with its impervious surfaces and modified drainage networks, often leads to what can be termed an “urban geochemical signature”. This talk will explore the potential for using standard water quality parameters (trace metals, major ions, nutrients, and physico-chemical parameters) to differentiate groundwater from tidal inflows, freshwater (riverine) inflows, and stormwater runoff within the context of an urban estuary.

Bio:

David is a hydrogeologist and water management specialist with fifteen years’ experience in environmental consulting. David graduated from the University of Plymouth (UK) in 2009 with a Masters in Geology and subsequently went on to complete a Masters in Hydrogeology from Newcastle University (UK). During his career David has worked throughout Australia and the UK supporting groundwater, surface water and contaminated land projects; providing advice on contaminant fate and transport, groundwater-surface water interactions, dewatering-discharge assessments, environmental licensing, remediation, and integrated water management. David has spent the past 9 years based in Sydney, NSW, where he has contributed technical advice to delivery of major construction projects including the M6, M8, Sydney Metro Tunnelling Packages, WestConnex, and Western Sydney Airport. David is Certified Environmental Practitioner and Director of Hydroview Consulting, a specialist water advisory consultancy based in Sydney, NSW. In his spare time David enjoys the trials of gardening, and home hydroponics.