The codes, authorities and engineering references that govern sustainable drainage, soakaway and geocellular design in the Kingdom — each summarised in plain English, with a link to its official source.
These set the regulatory framework for stormwater and drainage works in the Kingdom. NGS summarises each below; follow the link to the official source for the full document.
| Document / authority | What it governs | Official source |
|---|---|---|
| SBC 701 — Saudi Plumbing CodeSaudi Building Code Committee | Building-level storm drainage, including roof and site drainage and subsoil drains, within the national building code framework. | sbc.gov.sa → |
| MOMAH — stormwater & flood policyMinistry of Municipalities & Housing | National municipal policy and oversight for drainage and flood management, delivered through the regional municipalities (amanat). | momah.gov.sa → |
| Balady — drainage approvalsNational municipal e-services platform | The permitting workflow for stormwater connection, drainage linkage and related municipal approvals. | balady.gov.sa → |
| Jeddah Stormwater Drainage ManualJeddah Municipality | Regional hydrology, rainfall intensity (IDF) data and drainage / infiltration criteria for the Jeddah area. | via municipality → |
| Riyadh Storm Drainage ManualRiyadh Municipality (Amanah) | Regional storm drainage design criteria and hydrological basis for the Riyadh area. | via municipality → |
These widely used references underpin the structural and hydraulic design of infiltration, attenuation and geocellular systems. They are design guidance, not Saudi law — but they are the recognised engineering basis applied across the region.
| Document | What it covers | Official source |
|---|---|---|
| CIRIA C737CIRIA, UK | Structural and geotechnical design of modular geocellular drainage systems — loading, cover depths and installation. | ciria.org → |
| CIRIA C753 — The SuDS ManualCIRIA, UK | The reference manual for sustainable drainage design, including infiltration systems, storage and drain-down behaviour. | ciria.org → |
| BRE Digest 365BRE, UK | The standard method for soakaway percolation testing and for sizing soakaways from the measured infiltration rate. | bregroup.com → |
| BS 8582 / BS EN 752BSI | Codes of practice for surface-water management and for drain and sewer systems outside buildings. | bsigroup.com → |
NGS does not host or distribute these copyrighted documents. Each link points to the official issuing body, where the document can be obtained.
In practice, a stormwater design in the Kingdom starts with the site's ground conditions — an infiltration (percolation) test determines whether a soakaway is viable or whether attenuation and controlled discharge are needed. The system is then sized and structurally checked against the recognised references above, and the drainage proposal is submitted for municipal approval through Balady. NGS supports this end to end: our Stormwater & SuDS division supplies the geocellular systems, and the NGS Design Studio produces a sized, standards-aligned soakaway design with a downloadable engineering summary.
What standards govern soakaway and stormwater design in Saudi Arabia?
Building-level stormwater drainage is covered by the Saudi Building Code (SBC 701). Municipal policy and approvals are administered by MOMAH and the Balady platform. Engineering design practice commonly references CIRIA C737 (geocellular structural design), CIRIA C753 (The SuDS Manual) and BRE Digest 365 (soakaway percolation testing and sizing).
Do I need a percolation test for a soakaway?
Yes. A soakaway only works where the ground can absorb water, so an on-site percolation (infiltration) test is required to confirm feasibility and to size the system. The BRE Digest 365 method is the common reference, and the results typically support the drainage submission to the municipality.
What is the difference between infiltration and attenuation?
Infiltration systems (soakaways) discharge stormwater into the ground. Attenuation systems store it temporarily and release it at a controlled rate into the network. The choice depends mainly on the soil's infiltration capacity and groundwater level — where soils drain poorly, attenuation is used instead.
Who approves stormwater drainage in Saudi Arabia?
Municipal authorities under MOMAH approve drainage works, with permits handled through the Balady platform. Large developments, giga-projects, or facilities such as Saudi Aramco sites may apply their own additional engineering standards on top of the national requirements.