Sustainable Drainage Reports FAQs

• House builders and developers
• Property professionals such as architects, planning consultants, and land agents
• Private individuals
• Businesses
• Insurance brokers and lenders

• Validating planning applications at Pre-Planning Stage
• Planning Conditions
• Building and flood mitigation design
• Due diligence
• Code for Sustainable Homes
• SuDS approval boards (SABs)
• Lending, mortgages, and pension funds

For initial screening at the conceptual design stage a SuDSmart or SuDSmart Plus Report typically supports developers and regulators with infiltration drainage advice. This is the preferred method for managing surface water without increasing flood risk downstream. When infiltration drainage cannot be undertaken at a site due to the underlying ground conditions, other more conventional drainage systems are introduced in our SuDSmart Pro Report (Note: infiltration drainage techniques are also considered when possible).

SuDSmart Pro Reports analyse the potential run-off from a site so that it can be managed effectively to ensure there is no increase in flood risk on or off the site. Post development run-off rates are assessed for a range of storm events including an allowance for future climate change. A drainage strategy is developed to offset the increase in surface water run-off from the new development using the principles of SuDS and the code for sustainable homes. The hydrological context of the site is assessed, along with any potential issues that may affect the SuDS system. A range of potential options are assessed including discharge to the ground, surface water courses or sewerage. The report provides sizes and flow rates for a range of sustainable drainage options that may be considered.

SuDSmart Reports can be used to support a planning application at Pre-Planning Stage, or alternatively address a Planning Condition prior to planning being granted. SuDSmart and SuDSmart Plus Reports provide a cursory look at infiltration SuDS which is the preferred method for managing surface water. Whether infiltration techniques are feasible or not will determine the suitability of other SuDS schemes going forward. The level of detail required depends on the specific requirements of your local authority.

You should note that our most detailed report, SuDSmart Pro provides alternative options and preliminary scheme layouts that should be subject to more detailed review at the master planning stage. In our experience, this level of detail is required for more stringent planning authorities or for more complex sites that warrant more detailed assessment.

All SuDSmart reports include recommendations for next steps. We will always advise on the most cost effective way to move forward and provide details of how to do this whilst meeting in the needs of the planning department.

GeoSmart are able to provide access to a range of highly experienced senior consultants and engineers through our sister company ESI Ltd., who can provide a more detailed review of your site specifics and planning requirements. ESI also provide soakaway/infiltration testing services and interpretive data review. Please contact a member of the GeoSmart team to put you in touch with ESI when further detailed assessment is required.

The GeoSmart SD50 map provides an assessment of the capacity of the ground to receive infiltration depending on the nature, thickness and permeability of the underlying material and the depth to the high groundwater table.

• Allows preliminary assessment of the site without the need for bespoke SuDS design.
• Use in conjunction with the SuDSmart report range to identify SuDS infiltration suitability and flow/volume design data.
• Combination may be sufficient to obtain outline planning.
• Provides customers with clear site risk profile on drainage cost and land area needed.

To discuss the SD50 SuDS screening map and how it can improve your planning submission for your client, contact us today.