SCP have been working with Harworth since 2016, to assist with the infrastructure design required for the redevelopment of Thoresby Colliery into Thoresby Vale.
Thoresby vale is a new residential development for 800 units, and will have a community hub and employment zone with new infrastructure throughout.
SCP were appointed during the planning stage, and have undertaken the feasibility studies, flood risk assessments, and the technically approved highways and drainage detailed design packages under S278, S38, S104, S106, S102 and S185 agreements and are now on site for construction site support for drainage works on Phases 1 and 2.
The drainage philosophy is to deliver a sustainable drainage solution through ponds, swales and tanks, to outfall in the nearby River Maun following agreement with the Environment Agency (EA) and the Local Lead Flood Authority (LLFA) on a restricted flow rate from the development
In designing the drainage, the attenuation storage caters for rainfall from a storm scenario of up to 1 in 30 in a tank solution, with 1 in 100 year storms with 40% climate change captured in an overland pond. This tank and pond system is connected via the hydro-brake flow control chamber with 900mm diameter pipes, allowing for flow in and out of the swale. This enables our drainage design to be sustainable, with no rainfall being delivered to treatment plants or combined sewers.
During the design, SCP supported the client to review the most commercially viable tanks solutions cognisant of the need for future adoption. A pre-fabricated DfMA (Design for Manufacture & Assembly) concrete tanks solution was determined to enable best value to be achieved through cost, time efficiency and site constraints. Incorporating an off-site delivery approach, the tanks were economical the standardised square shape enabled increased storage on the same footprint as other piped solutions. They are also able to be pre-fabricated to irregular shapes and installed with less cover as their structural integrity is greater than a large piped system. Adjacent to the tank, and as part of the drainage solution, hydro-brake chambers are located to control the outfall rate, to achieve he restricted flow rate, which are 3.0m x 3.0m square with reinforced concrete.
The work currently being undertaken on site caters for the phases 1 and 2 of the development only. The site wide drainage strategy developed by SCP, delivers a strategy that is commercially viable for the client, whereby the drainage system can be extended as future phases are constructed, and ultimately just tapping in and extending the existing network, mitigating the requirement to construct extensive drainage systems from the outset prior to any development commencing on site.