SuDS Design and SAB Applications Across Wales

Practical surface-water drainage design and SAB application support for new homes, conversions and small residential developments across Wales, provided by a CIRIA-trained Chartered Architectural Technologist.

SuDS FEASIBILITY AND TESTING

Early assessment of the site, proposed development and available drainage options. This can include drainage-hierarchy reviews, site constraints and BRE 365 infiltration testing.

SAB APPLICATIONS

Preparation of drawings, calculations, compliance statements and maintenance information for submission to the local SAB, including support with technical queries during the assessment.

DRAINAGE DESIGN

Practical design of soakaways, infiltration trenches, attenuation features, flow controls, permeable surfaces and rainwater-management systems appropriate to the site.

WHAT ARE SuDS DESIGNS AND SAB APPLICATIONS?

Sustainable Drainage Systems—known as SuDS—manage surface-water runoff in a way that reduces flood risk while considering water quality, biodiversity and the long-term use of the development.

In Wales, qualifying developments generally require approval from the local Sustainable Drainage Approval Body before construction begins. SAB approval is separate from planning permission and requires its own technical design, application and fee.

INFILTRATION DESIGN - RESIDENTIAL ANNEX AT SARNAU, CEREDIGION

Project: New build residential annexe
Service: Infiltration testing, gravel-filled soakaway trench design and SAB application
Constraint: Challenging site levels and coordination with the proposed external works
Solution: A shallow stone-filled infiltration soakaway system designed to work with the available levels and proposed landscaping
Outcome: Complete technical package APPROVED by the local SAB authority.

ATTENUATION DESIGN - STORAGE BUILDING AT LLANGOEDMOR, CEREDIGION

Project: Replacement storage shed
Service: Infiltration testing, attenuation basin design and SAB application
Constraint: Very poor ground infiltration, preventing disposal through a conventional soakaway
Solution: A vegetated attenuation basin with a flow-controlled outlet to an existing watercourse
Outcome: Complete technical application package APPROVED by the local SAB authority, providing a cost-effective solution that makes use of the site's existing features.

CASE STUDIES

PROJECT STAGES

From Feasibility to Determination

Initial project review
You provide the site location, proposed drawings, topographical information and any existing drainage or ground-investigation records.

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Site assessment and testing
The site constraints and drainage hierarchy are reviewed. Where infiltration is proposed, suitable BRE 365 testing may be required close to the intended drainage location.

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SuDS design
An appropriate strategy is developed, supported by the necessary storage calculations, levels, flow controls, construction details and technical drawings.

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Application preparation
The drawings, calculations, standards statements, maintenance information and supporting documents are assembled for the SAB application.

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Submission and technical quieries
Subject to the agreed project scope, the application is submitted and any proportionate technical queries raised during the SAB review are addressed.