What You Need to Know About the London Sustainable Drainage Proforma
If you have an upcoming development in the London area which requires a sustainable drainage...
These reports are often used as part of planning applications or planning condition discharge, especially where infiltration forms of Sustainable Urban Drainage Systems (SuDS) are recommended. Sustainable Urban Drainage Systems (SuDS) aim to alleviate drainage problems by dealing and treating surface water runoff at source, or by attenuating this and then releasing it back into the surface water network at a much lower rate.
Local Planning Authorities (LPA) and Lead Local Flooding Authorities (LLFA) request SuDS reports at planning application stage, to ensure that development proposals have considered the surface water runoff arising from a development and have feasible proposals in place prior to commencing a development. The main reason for this is that SuDS do require space, and all infiltration devices must be located a minimum of 5 metres away from a habitable building.
Obviously, most developers want to make the most of the available space on a development therefore, there may not be any space for a soakaway. Therefore, should the BRE365 percolation pass and there not be available space for a soakaway, the planning authority may ask the client to change the site layout in order to provide space to allow infiltration.
Therefore, typically for major developments where a desktop geological study shows underlying geology with potential for infiltration, the LPA and LLFA will request that a BRE365 infiltration test is carried out on the site, in order to show that the SuDS hierarchy has been followed, and also should the test fail, this allows us to investigate further methods of restricted surface water disposal in order to ensure that SuDS can be included in the development and that there is somewhere for any restricted surface water discharge to be conveyed.
Moreover, sites with high clay content soil and/or a high water table are also not suitable areas for a Soakaway.
Carrying out a Percolation Test demonstrates to your local authority you have conducted the necessary steps to find out this information as part of your planning application.
“I have really enjoyed working with Nimbus. Sadia is extremely knowledgeable and is always willing to go out to her way to help clients. The speed at which Nimbus produce their work is impressive and the prices are extremely competitive. Special mention to Ryan Herity after we worked closely together on a couple of schemes. Always happy to pick up the phone and answer questions. He provided solutions that led to drainage officer approvals – you can’t ask any more than that!”
“I have used Nimbus Engineering Consultants for several years now. The service is second to none. Sadia effectively communicates throughout the entire process. Nimbus has never let me down. I would wholeheartedly recommend Nimbus for any and all SuDS advice. Nimbus shoot from the hip, and make my life easy, knowing if I have engaged them, I do not have to ever worry.”
“We’ve collaborated with Sadia on a few projects; Nimbus Engineering’s proposals were well-informed, attentive of regulatory trends and wrapped in proactive attitude.”
We have been working with Nimbus Engineering for some time in a collaborative approach, allowing us to provide our clients with a complete Engineering service. Primarily providing us with SuDs, foul and surface water design, along with highways design and detailing, Nimbus have given us a great service, both prompt and efficient.
We at Rouf Homes have been using Nimbus Engineering for a number of years, for all matters relating to Drainage design, Flood risk and Sustainable Urban Drainage Systems design. We find them to be very knowledgeable on these matters, approachable, efficient and very cost effective
Richardson and Peat Ltd are pleased to be associated with Nimbus Engineering for their work on our Surrey school projects for new autistic teaching centres, with exemplary forward-thinking on the issues facing us with surface water attenuation they have not only dealt with the problems cost-effectively but by detailed design of rainwater gardens and swales have also enhanced the projects. Our company look forward to a continuing working relationship with Nimbus Engineering in the future.
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