Sustainable Drainage Systems (SuDS) are becoming an integral part of new development planning submissions, driven by Local Authority Water and Flood Management Plans.
SuDS manage peak runoff after a rainfall event to prevent flooding. They try to mimic what would happen if there was no development on site. They can be designed to convey surface water and slow runoff down (attenuate) before it enters watercourses.
Surface water should infiltrate into the soil directly but this may not always be possible as a single solution. This can be due to different soil and rock types, groundwater levels and slope profile.
Local Authorities are now looking for the inclusion of SuDS into new developments. They must now be applied to all major schemes of 10 units or more.
In many instances now, Architects and planning consultants need to demonstrate why a SuDs is not appropriate for the site. If they can’t, then they need to consider how an appropriate SuDS will be integrated to the development so that it does not increase flood risk on site or elsewhere.
Planning conditions on SuDS vary considerably across the country. It is crucial that Architects and planning consultants understand these differences, assess the site and design a SuDS scheme that meets planning requirements on behalf of their client.
We have developed a unique catalogue of planning authority SuDS requirements.Choose your region
We have many years experience in assessing site drainage and designing suitable SuDS systems as part of Master planning and pre-application submissions.
We have a proven track record of delivering successful schemes through our technical expertise. Our drainage reports provide:
For initial screening at the conceptual design stage a SuDSmart or SuDSmart Plus Reports typically support 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, suppliers and engineers, who can provide a more detailed review of your site specifics and planning requirements.
Please contact a member of the GeoSmart team to put you in touch 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.
To discuss the SD50 SuDS screening map and how it can improve your planning submission for your client, contact us today.