Four ways to demonstrate SuDS compliance with Scalgo Live
- Urban development
The updated Sustainable Drainage Systems (SuDS) standards, introduced by DEFRA in 2025, mark a clear shift from design guidance to performance-based evidence. Developers and designers must now show, not just state, that rainfall is managed on site during both everyday and extreme events.
Scalgo Live offers a practical, data-driven way to demonstrate that compliance. By combining terrain data, rainfall analysis, and infiltration mapping in one continuous platform, practitioners can easily understand how water moves across a development site and prove that their design meets the new expectations.
An example development site designed in Scalgo Live.
Here’s a few ways you can use Scalgo Live to meet the new guidelines.
1. Map how rainfall is retained on site
Under Standard 2, developments must now retain or reuse the first 5 mm of rainfall rather than allowing it to enter sewers or watercourses. This small-event focus demands a level of spatial precision that spreadsheet methods cannot provide.
In Scalgo Live, designers can map flow paths, depression storage, and infiltration capacity across every surface. The platform lets you adjust surface types, test infiltration rates, and instantly see how changes affect interception performance.
You can see where the first few millimetres of rain actually go, it’s performance you can verify, not just calculate.
These visual results give planning authorities transparent, verifiable evidence that frequent rainfall is being managed close to source, strengthening the approval process and reducing uncertainty.
Surface water runoff volumes in (1) winter setting with 5 mm rain, and in (2) summer setting with 25 mm rain, pre-development, and both with and without SuDS.
2. Analyse extreme rainfall and flood safety
Standard 3 extends the requirements to extreme rainfall, ensuring that developments remain flood-safe in 1-in-30-year and 1-in-100-year scenarios, including climate allowances.
Scalgo Live supports this through terrain-based modelling that identifies overland flow routes and exceedance corridors before detailed hydraulic design begins. With DynamicFlood, you can simulate both historical and design rainfall events to see how attenuation features perform and where residual risk remains.
This capability bridges the gap between design intent and demonstrable resilience. Practitioners can directly compare pre- and post-development conditions, with or without SuDS features, and quantify improvements in flood performance.
Flow graphs and peak flow volumes across the development site pre-development, and both with and without SuDS.
3. Collaborate and share evidence with confidence
Beyond modelling, Scalgo Live strengthens collaboration between engineers, planners, and regulators. Its outputs integrate seamlessly with common GIS and CAD tools, allowing everyone to work from the same datasets and visualisations.
When reviewers can see how a site performs under different rainfall conditions, discussions become more focused and decisions more transparent.
Shared evidence builds shared confidence!
4. Explore retrofitting and adaptation options
The DEFRA 2025 standards apply not only to new developments but also to existing urban areas. Many local authorities are now incorporating SuDS retrofits and green infrastructure into regeneration plans.
In Scalgo Live, users can test a wide range of SuDS measures – from rain gardens and green roofs to detention ponds and bioswales – within a single, data-driven environment. The terrain model and land cover map can be easily edited to explore different configurations and see how interventions affect both local flooding and wider catchment behaviour.
Property and street flooding issue in densely built urban area
Retrofitting SuDS and solving flooding issues in Scalgo Live
From policy to performance
The new SuDS standards set clear expectations: intercept everyday rainfall and manage extremes safely. Scalgo Live provides a single environment where practitioners can design, test, and prove that performance.
In the era of performance-based drainage, Scalgo Live isn’t just a modelling tool. It’s the new standard for demonstrating that SuDS deliver exactly what policy now requires.
