Water is Australia’s most precious natural resource and, in a country where drought, population pressure and lack of water is a significant feature of our climate and our landscape, the security of clean healthy freshwater resources and coastal waterways, including waters around the Great Barrier Reef, is critical to individuals, communities, industry and the environment.

The health and quality of our inland and coastal waterways are under profound threat due to increasing human activity and climate change as well as the environmental impact from bushfire sediment, storm events, pollution and contamination.

AquaWatch Australia’s core objective is to develop a user-driven, nationally integrated ground-to-space water quality monitoring system that provides the necessary information for decision-making to safeguard the health, quality and safety of our waterways, reservoirs and coastal waters, using Earth observation data and spatial technology.

This system will require the development and integration of three key components: specially designed satellite sensors; the augmentation and interconnection of existing ground monitoring sensors to form a dense in-situ sensor network; and a dedicated data analytics platform to integrate the ground and spacebased data with models and analytical tools.

By design, end-user consultation and co-design are included as essential aspects for the development of the AquaWatch system with the feedback and outcomes feeding into and supporting ground and satellite system design, data analysis and for building the overall mission operational plan.

This document provides a summary of detailed end-user consultation process, including the outcomes of discussions from several workshops conducted between July 2020 and June 2021, which provided very rich and useful guidance for design of the AquaWatch technical system requirements. Further end-user engagement is planned along all development and implementation phases of the mission.

During the initial consultation process, over 90 participants were approached, and grouped across the following end-user categories:

• Planning and Environment Users (including BoM, Geoscience Australia (GA), along with a range of State and Commonwealth agencies and peak bodies)
• Water Utilities (including water suppliers and the hydro-power industry)
• Primary Industries (broad range of users from agriculture and aquaculture)
• Water Sciences (specialists in water quality research from academia, non-governmental organisations (NGOs) and Commonwealth Scientific Industrial Research Organisation (CSIRO).

The AquaWatch end-user analysis team summarised the various contributions from the end users into measurable or quantifiable variables, that are required to gain insight into processes affecting the aquatic ecosystems as well as environmental reporting. Key variables identified included: the composition of the water column, water column depth and/or substratum; water body extent and volume; water temperature; biogeochemical variables; disease related variables and micropollutants.

The analysis resulted in very valuable insights into key variables, but also how the AquaWatch-derived information would be used. Multiple participants highlighted the necessity to include the characterisation of surrounding landscapes, climate and land-use activities to better attribute primary drivers of change in coastal and inland water quality.

Several end-users noted that there are situations where access to AquaWatch data in Near Real Time (NRT) would be invaluable for time-critical decision making and to provide early warning. NRT decision ready information needs to span large areas with high spatial resolution (resolve streams), with temporal
frequencies mentioned of hours, to daily: the actual frequency being problem dependent. Predicting extreme events or managing the consequences of extreme events will impact the data processing infrastructure required. Essential criteria related to managing extreme events are near real-time delivery of data, including analysis, to the relevant authorities and organisations involved.

On the other hand, change and trend detection require valid, accurate long-term timeseries of information as subtle changes need to be recognised as early as possible, indicating an ecosystem is being affected by stressors or recovering due to e.g. management interventions. There was considerable agreement that many end-users would also like to see the water quality forecasting and modelling extend as far as possible (e.g. 3 days or longer) into the future, in order to empower timely management decisions.

Many participants stressed the importance of open access, and ease of access to data and derived information from AquaWatch Australia. Government departments stressed the need for the data to be formatted in a consistent, agreed manner for easy ingestion into their own departmental systems, and that data should be made available via an automated querying system. Generally, it was felt that the large volumes of data require agreement of key standards to ensure consistency in data quality and analysis, as well as easy-to-use tools to manage/select/choose relevant temporal and spatial subsets of interest.

User-requirements covered a very broad range of requirements by potential end-users, that poses significant technical challenges and trade-offs in AquaWatch program design, in order to balance technical efficiency, breadth and depth, and quality of measurements, as well as short term versus long term impact and benefit.

Throughout this process, our aim has been to develop the strongest possible business case for AquaWatch alongside a feasible technical system design. This implies building an AquaWatch Australia system at a reasonable cost, but which satisfies the broadest possible range of end user requirements. As a system, AquaWatch Australia will be unparalleled world-wide in terms of performance and functionality, but it may not be all things to all people. Design trade-offs are inevitable. Throughout the end-user consultation process one major trade-off was identified between “revisit time” (or how frequently a part of Australia is imaged by the Earth observation satellites) and the spatial ground resolution (pixel size) and data fidelity achievable by the EO satellites.

One area where such trade-offs are unlikely to be necessary is in computing infrastructure. Initial assessment into computing infrastructure for the AquaWatch Australia Data Analytics system have shown that scalable cloud computing resources can adequately service the necessary processing capacity for various user-needs.

User-expectations for the operation of the AquaWatch in-situ water quality sensor network, were also significant. The sensor-network is expected to be dense and extensive, providing wide coverage of Australia’s key inland and coastal waters, also providing unencumbered data access in remote areas of Australia where communications connectivity is limited. Some of the higher-performing water quality sensors are not necessarily cheap, easy to deploy, reliable or easy to maintain. There is therefore a strong imperative for AquaWatch to become a catalyst for industry, data communication providers and sensor developers, to help improve the cost: performance issues that will provide the required service. The AquaWatch Australia technical team has developed an In-Situ Sensor Network ‘green paper’, addresses these requirements (See Malthus & Dekker, 2021).

Further, iterative end-user consultation will be done as the mission progresses, and through a dedicated End-Users Advisory Group (EUAG). This will be the primary interface for engaging the broad end-user community. The EUAG is intended to be a cross section of end user groups that provide an ongoing perspective issues and needs of their segment of the end-user community.