This tool calculates the hydraulic loading rate for wastewater irrigation using a water balance approach, as outlined in NSW Department of Local Government (1998). It replaces generic crop factors with site-specific evapotranspiration data to improve accuracy.
Hydraulic loading is a critical factor in designing sustainable wastewater irrigation systems. If calculations show that more water is applied than can be used or lost through evapotranspiration, you must plan for onsite storage. Offsite disposal is generally not supported unless a licensed facility can accept the wastewater under an approved agreement.
This calculator helps you determine whether your site can sustainably manage the volume of wastewater generated, ensuring that excess water does not lead to runoff, waterlogging, or environmental harm. It supports planning for infrastructure such as storage dams or adjusting irrigation areas to match site capacity.
Use this tool to make informed decisions about wastewater reuse that align with regulatory expectations and environmental protection goals.
Refer to Water quality protection note no. 22 for further guidance.
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