Engineers challenged to solve a “tight-fit” surface water management challenge on a new homes development in West Yorkshire turned to Hydro-Brake Optimum® to keep flood protection measures well within safe limits.

At the Saffron Park housing development in Liversedge, the designers Paul Waite Associates Ltd needed to engineer stormwater attenuation in an extensive pipe storage area, necessary because of the topography of the site and the preference of the water authority.

To ensure that the discharge rate limits were met despite the site constraints, Hydro International’s Hydro-Brake Optimum® vortex flow control was specified to control the outflow to the drainage network.

“When we calculated the drainage discharge from the site and the available storage provision, it was going to be difficult to achieve the maximum limit of 110 l/s for 1 in 100 years flood event, plus an allowance for climate change. Using conventional flow control devices would have required more back up storage than would fit in the space available,” explains Luke McCabe of Paul Waite Associates.

“However, when we used the online Hydro-Brake Optimum® Design Tool, it showed that we could recommend a Hydro-Brake Optimum® as it required less storage and met the Environment Agency’s planning requirements easily. The Design Tool allowed us to output drawings and data and was simple to use.”

Saffron Park, in Liversedge, is located between Huddersfield and Leeds and comprises 52 two to five bedroom houses on a plot sandwiched between existing housing and two roads. The site falls nearly three metres from north to south, and surface water from roadways and drives drains via gulley traps to the temporary storage provision along the lower perimeter next to Miry Lane.

“Yorkshire Water had indicated that they preferred concrete pipe storage to cellular storage reservoirs if they were going to adopt the drainage scheme,” continued Luke McCabe. “This necessitated nearly 220 m3 of storage in three 1.2 m concrete pipes, each nearly 50 metres long.

“The pipes were buried at a depth of nearly three metres under the narrow landscaped strip at the lower perimeter; there was no room for more pipe storage if we had wanted it. The Hydro-Brake Optimum® discharges to the public storm drain.”

Since its launch in 2012, Hydro-Brake Optimum® has set new standards in design versatility with its unique ability to achieve up to 15% additional stormwater storage savings compared to conventional vortex flow controls. Independently certified by the BBA and WRc, Hydro-Brake Optimum® is the only vortex flow control whose physical geometry can be precision engineered by fine-tuning the all-important hydraulic design curve.

Hydro-Brake Optimum® is included within the latest industry-standard Micro Drainage design tool allowing engineers to precisely specify the size and hydraulic performance of flow controls to meet their design objectives. The complimentary Hydro-Brake Optimum® Design Tool at www.hydro-int.com provides online support for engineers to design flow controls and output detailed design drawings.

For more information about the Hydro-Brake Optimum® call the Hydro-Brake® Hotline on 01275 337937, email enquiries@hydro-int.com or visit the Hydro-Brake Optimum product page.