Top 10 Best Septic Design Software of 2026

Visual OnSite is a leading CAD-based software for designing onsite wastewater systems, including septic tanks, drain fields, and advanced treatment systems. It integrates soil evaluation tools, hydraulic calculations, percolation tests, and 3D modeling to ensure compliance with state and local regulations. The software generates professional drawings, reports, and cost estimates, streamlining the entire design process for engineers and designers.

SeptiCAD is a specialized CAD-based software for designing on-site wastewater treatment systems, including septic tanks, drainfields, and soil absorption systems. It automates complex calculations for sizing, percolation tests, and hydraulic loading while ensuring compliance with state and international codes. The tool excels in generating professional DWG drawings, PDF reports, and customizable plans for engineers and designers.

Site3P from Mintek Resources is a professional-grade software designed specifically for onsite wastewater (septic) system design, handling everything from soil evaluations and percolation tests to sizing tanks, drain fields, and advanced treatment systems. It automates complex calculations based on user-input data and complies with regulations across dozens of U.S. states and provinces. The software generates detailed reports, drawings, and permitting documents to streamline the design-to-approval process for engineers and regulators.

Onsite Sewage & Septic System Designer from citizensguide.net is a specialized Windows-based software tool for designing onsite wastewater treatment systems, including septic tanks, drain fields, and mound systems. It performs essential calculations for soil loading rates, percolation tests, hydraulic flows, and sizing based on local codes. The software generates printable reports, sketches, and compliance documentation to streamline the design process for professionals and informed homeowners.

HydroCAD is a powerful stormwater modeling software primarily used for hydrologic and hydraulic analysis of drainage systems, supporting methods like NRCS TR-20, TR-55, and Rational Method. While not a dedicated septic design tool, it offers capabilities for infiltration modeling, subcatchment analysis, and runoff calculations that can indirectly support septic system planning, such as evaluating drain field hydrology or site percolation. It generates detailed reports for regulatory submissions but lacks specialized septic features like tank sizing, soil loading rates, or leach field layout tools.

AutoCAD Civil 3D is a comprehensive civil engineering CAD platform from Autodesk, offering advanced tools for infrastructure design, including pipe networks and grading capabilities that can model septic systems like tanks, laterals, and drain fields. It integrates topographic surveys, surface modeling, and hydraulic analysis to support septic design within broader site development projects. While powerful for 3D visualization and clash detection, it requires customization for specific septic regulations and sizing calculations.

Carlson Hydrology from Carlson Software is a CAD-integrated tool primarily for hydrologic and hydraulic analysis, stormwater design, detention ponds, and pipe networks, with capabilities extending to sanitary sewer and basic septic system layout through site grading and drainage modules. It supports percolation analysis, leach field sizing, and tank placement within broader civil design workflows but lacks deep specialization in on-site wastewater regulations compared to dedicated septic tools. The software excels in producing detailed plans and reports compliant with engineering standards, making it suitable for integrated site development projects.

Bentley PondPack is a professional-grade stormwater modeling software from Bentley Systems, focused on hydrologic and hydraulic analysis for ponds, detention basins, and urban drainage systems. It includes advanced infiltration and percolation modeling capabilities, such as Green-Ampt and Horton methods, which can be applied to preliminary septic system assessments like soil loading rates. However, it lacks dedicated features for septic tank sizing, leach field design, regulatory compliance checklists, or onsite wastewater treatment specifics, positioning it as a general hydrology tool rather than a specialized septic design solution.

XPSWMM is a powerful stormwater and wastewater management modeling software based on the EPA SWMM engine, designed for simulating hydraulic and hydrologic processes in urban drainage, sanitary sewers, and combined systems. While it can model basic septic components like tanks (as storage nodes) and leach fields (via exfiltration), it is not tailored for septic design and lacks specialized tools for sizing, soil percolation analysis, or regulatory compliance. It excels in dynamic simulations for larger networks but is overkill for standalone septic systems.

InfoSWMM, from Autodesk (formerly Innovyze), is a powerful stormwater and wastewater modeling software based on the EPA SWMM engine, designed for simulating complex urban drainage, sanitary sewer, and combined systems at municipal scales. It excels in hydrologic and hydraulic modeling, real-time control, and integration with GIS and BIM tools. However, it is not tailored for septic system design, lacking specific features for onsite wastewater treatment like soil percolation analysis, septic tank sizing, or drain field layouts.