Slindon Parish Council - Pond Biodiversity and Drainage

Tender description

This is not an invitation to tender but 'notice of award' only. The award has been made in line with the Parish Council's Financial Regulations and Standing Orders, whereby the opportunity was made available only to a number of particular economic operators selected for that purpose and was not advertised elsewhere (in compliance with the Public Contracts Regulations 2015, article 110, paragraph 5). Slindon Pond as an attenuation pond has a key role to play in effective flood management, through the retention of rainwater and controlled discharge of excess water through an outlet structure. Numerous incoming drainage pipes form part of the overall system. The current construction of the system has a number of limitations which are increasingly impacting the pond's storage capacity, as well as restricting flows into the pond from the incoming drainage pipes. The incoming pipes primarily serve run off from the public highway. Whilst routine maintenance work has been undertaken over the years, the removal of substantial layers of silt is now required to improve the capacity of the pond, coupled with material changes to the existing incoming/outgoing infrastructure, through engineering works. Numerous works have also been carried out by WSCC in the past to improve the highway drainage system but have proved largely ineffective. The position has deteriorated such that significant flooding is occurring on the public highway in the vicinity of the pond with increasing frequency and also causing damage to the road surface. The pond is around 850 metres square and is constrained by an embanked area and woodland to the south and Church Hill to the north. Project Respond will address a ground water flood risk through both material changes to, and increasing the drainage capacity of, the existing infrastructure. This will be achieved by - • Removing a willow tree, where its extensive root system has infiltrated the inflow pipes. • Increasing the capacity of the pond by dredging and de-silting, silt to be sent to a licensed waste management facility. • Pond revetment and stabilising the banks adjacent to the northern bank, at the edge of the highway. • Changes to incoming and outgoing pipe structures, delivered through material improvements to existing infrastructure and new infrastructure installations and builds.