Surface water management is a crucial aspect of any land development project. The projected increase in rainfall intensity due to climate change has already caused several disputes between neighbours, where water has now inundated, and negatively impacted, properties causing financial losses by reducing the usable land, and increased sedimentation causing water quality impacts to waterways and other water sources.

In this article, we will explore why surface water assessments are so important. We will also discuss the process of site selection, a statutory approvals perspective, the challenges, benefits, best practices, and solutions for surface water management for this type of projects and provide some case studies and examples of our successful outcomes.

For more information see our Renewables Capability Statement.

What are the different types of Surface Water

There are predominately two (2) sources of surface water in farming zones.

1. Riverine: inundation caused by riverine flooding (rivers, creeks, drains etc).

2. Overland flow: inundation caused by stormwater rainfall and runoff from a direct catchment (storms).

The Process of Site Selection

Site selection is a critical step in the planning and development of any renewables project, as it can influence the feasibility and suitability of the project, as well as the extent and nature of the surface water management required. The site selection should consider the hydrological and hydraulic characteristics and potential constraints of the site and its surroundings, such as the topography, soil, geology, climate, rainfall, runoff, flooding, erosion, sedimentation, water quality, and environmental features and conditions. When selecting an appropriate site, SWM Consulting recommends the following process:

1. Pre-development Advice: Apply for pre-development advice from the relevant authority. This can be Councils, Catchment Management Authorities (rural Victoria), Melbourne Water (suburban Melbourne), NSW water, SA water and other authorities. These authorities will provide a certificate or “letter” determining the flood risks.

2. Undertake a Feasibility Assessment: It is important to understand the catchment characteristics, the location of neighbouring dwellings, and the likelihood of potential impacts to neighbouring land. These are relatively quick assessment of a property parcel that assist in the pre-purchasing and can save you purchasing an unsuitable property or project.

3. Communication: Speak to the land owner, local indigenous organisation, and the neighbours. In many cases it is difficult to discern the exact direction of flow from “eyeballing” the site. Speaking to the landowners and neighbours will shed more light on the subject and assist in developing a rapport with the local community

Optional (recommended): Undertake a Flood Impact Assessment, though these are in some cases cost prohibitive, Flood Impact Assessments provide a detailed review of the surface water conditions on site, modelling the hydrologic and hydraulic flood characteristics, outline potential mitigation options, propose changes to the project plans which assist in final approvals.

If you are interested in a Feasibility Assessment or Flood Impact Assessment, please contact admin@swmconsulting.com.au or call us on 0493 224 496.

The Statutory Compliance Perspective

Within Farming Zones, “earthworks which change the rate of flow or the discharge point of water across a property boundary” require a permit. This condition has by-in-large not been addressed in many rural areas, instead neighbours generally come together to find a solution that is mutually beneficial. However, as mentioned above, there are growing instances where this type of issue is becoming a source of angst and VCAT applications. The primary guideline to assess flood impact on development are:

• In Victoria, is DELWP’s Guidelines for Development in Flood Affected Areas 2019.

• In NSW, is NSW Environment and Heritage’s Flood Risk Management Guide 2019.

• In Queensland, is Queensland Reconstruction Authority’s Queensland Flood Risk Management Framework 2021.

• In South Australia, is Government of South Australia’s Flood Hazard Risk Reduction Plan 2024.

The guidelines are used to assess development in locations known or suspected to be flood affected. The key principles for development outlined in the guidelines are:

• Protect human life and health and provide safety from flood hazard.

• Minimise flood damage to property and associate infrastructure.

• Maintain free passage and temporary storage of floodwaters; and,

• Protect and enhance the environmental features of waterways and floodplains.

From a compliance perspective, it is important to understand the surface water nature on site and negate any potential impacts. This will not only future proof the development but will assist if any actions are brought against the development into the future.

The Challenges and Risks of Surface Water Management for Renewable Energy Projects (BESS, Solar and Wind Farms)

Renewable (BESS, Solar and Wind Farms) projects are typically large-scale projects that cover vast areas of land, often in rural or remote locations. These projects can have significant impacts on the natural hydrology and hydraulics of the site and its surroundings, such as:

• Flooding: Altering the runoff patterns, volumes, and velocities of surface water, potentially increasing the flood risk for the project itself as well as downstream areas. Flooding can damage the infrastructure and equipment of the project, as well as pose safety hazards for the workers and the public.

• Erosion: Increasing the soil erosion and sediment transport due to the removal of vegetation, the installation of foundations and structures, and the creation of access roads and tracks. Erosion can reduce the soil quality and stability, as well as affect the water quality and aquatic habitats downstream.

• Water Quality: Generating large amounts of sediment and other pollutants or contaminates during the construction and operation phases, which can accumulate in the surface water bodies and channels, reducing their quality, capacity and functionality. Sedimentation can also affect the water quality and aquatic habitats downstream, as well as increase the maintenance costs and requirements for the project.

These challenges and risks can pose significant threats and costs for the project, as well as for the stakeholders and the community involved. Therefore, it is essential to conduct a comprehensive and robust surface water assessment for any BESS, solar and wind farm project, to identify, quantify, and mitigate these impacts, and to ensure the sustainability and viability of the project.

The Benefits and Opportunities of Surface Water Management for Renewable Energy Projects (BESS, Solar and Wind Farms)

Surface water management is not only a necessity, but also an opportunity for renewable projects, as it can provide various benefits and advantages for the project, such as:

• Water harvesting, storage, and reuse: Capturing, storing, and reusing the surface water runoff from the site, reducing the reliance on external water sources and enhancing the water security and efficiency of the project. This can also reduce the water demand and stress on the local and regional water resources, especially in areas with water scarcity or drought conditions.

• Water conservation and protection: Renewable projects can implement measures and practices to conserve and protect the surface water resources and quality, such as minimising the disturbance and imperviousness of the site, using erosion and sediment control devices, applying best management practices for stormwater and wastewater management, and restoring and enhancing the natural drainage and vegetation of the site. This can also improve the environmental and social outcomes and performance of the project.

• Biodiversity, landscape, and amenity enhancement: Renewable projects can integrate the surface water management with the design and layout of the project, creating and maintaining features and elements that enhance the biodiversity, landscape, and amenity values of the site, such as wetlands, ponds, swales, rain gardens, and green roofs. This can also increase the aesthetic and recreational appeal and attractiveness of the project.

These benefits and opportunities can add value and competitive edge for the project, as well as for the stakeholders and the community involved. Therefore, it is worthwhile to invest in and optimize the surface water management for any solar and wind farm project, to maximize these benefits and opportunities, and to ensure the success and profitability of the project.

The Solutions for Surface Water Management for Renewable Energy Projects (BESS Facilities, Solar and Wind Farms)

The “solution” for Surface Water Management changes from site to site. It requires complex management of storage and conveyance of water using a combination of knowledge, skills, and tools to achieve the best outcomes. SWM Consulting utilises the best practise hydrologic software package RORB, as well as the best practise hydraulic software suite TUFLOW to develop comprehensive, implementable and approvable Surface Water Management Plans and Assessments.

In determining a solution, the project design is the limiting factor i.e. how far down the design process has the surface water management assessment been requested. In an ideal world, the surface water management would inform the design, however, this is not always the case.

The best practices and solutions for surface water management for these projects are largely down to the proposed design layout as the crucial step in the planning and development of renewables project. The design layout can determine the performance and functionality of the project, as well as the effectiveness and efficiency of the surface water management implemented. The design should incorporate the principles and practices of sustainable and integrated surface water management, such as the following:

• Maintain existing discharge: The design should aim to maintain the generation and discharge of surface water runoff and reduce the pollutants from the site, by minimising the disturbance and imperviousness of the site, using permeable and porous materials and surfaces, and preserving and enhancing the natural drainage and vegetation of the site.

• Erosion and sediment control: The construction should implement measures and practices to prevent and minimize the erosion and sediment generation and transport from the site, such as installing and maintaining erosion and sediment control devices, such as silt fences, straw bales, geotextiles, and check dams, stabilising the exposed and disturbed areas, such as seeding, mulching, and revegetating, and managing the construction activities and operations, such as scheduling, sequencing, and monitoring.

• Environmental management: The construction should implement measures and practices to protect and enhance the environment and the ecology of the site and its surroundings, such as complying with the environmental laws and policies, such as the Environment Protection and Biodiversity Conservation Act 1999, the Water Act 2007, and the Victorian Planning and Environment Act 1987, conducting regular environmental audits and inspections, and implementing environmental management plans and systems.

• Operation: The operation is an ongoing step in the maintenance and improvement of any renewable energy project, as it can influence the reliability and sustainability of the project, as well as the optimisation and innovation of the surface water management adopted.

• Monitor: The operation should monitor and evaluate the performance and functionality of the surface water management features and elements, as well as the impacts and outcomes of the surface water management for the project, using various methods and tools, such as sensors, meters, gauges, cameras, and software. These methods and tools can also provide data and information for the operation and improvement of the surface water management for the project.

• Maintain: The operation should maintain and repair the surface water management features and elements, as well as the infrastructure and equipment of the project, using various methods and tools, such as cleaning, flushing, replacing, and upgrading. These methods and tools can also ensure the quality and durability of the surface water management for the project.

• Improve: The operation should improve and optimise the surface water management features and elements, as well as the performance and functionality of the project, using various methods and tools, such as feedback, analysis, research, and innovation. These methods and tools can also enhance the effectiveness and efficiency of the surface water management for the project.

Final Thoughts

Surface water management is a vital and valuable component of any solar and wind farm project, as it can affect the feasibility, suitability, sustainability, and profitability of the project, as well as the impacts and outcomes for the stakeholders and the community involved. Therefore, it is important to conduct a thorough and rigorous surface water assessment for any solar and wind farm project, to identify, quantify, and mitigate the challenges and risks, and to maximize the benefits and opportunities of the surface water management for the project. It is also worthwhile to invest in and optimize the surface water management for any solar and wind farm project, to achieve the best outcomes and solutions for the project, using the best practices and tools available.

If you need any assistance or advice on surface water management for your renewables project, please contact us at admin@swmconsulting.com.au, and we will be happy to help you.

Thank you for reading this article, and we hope you found it informative and useful.

Please feel free to leave your feedback, comments, or questions below, and we will get back to you as soon as possible.

For case studies and examples of successful Surface Water Management see our Renewables Capability Statement.

Additional resource:

The Leading Practice Principles First Nations and Renewable Energy Projects by the First Nations Clean Energy Network is a valuable resource as by incorporating the principles and associated practices into your operations and decision-making processes, renewable energy projects can demonstrate they are respecting the rights of First Nations peoples and improving outcomes for First Nations rightsholders and communities. This guide outlines First Nations expectations for the sector and details the key considerations for First Nations engagement at each stage of the project lifecycle.