Plastic piling and weirs at NE's Thorne Moors

Tender description

This work is being undertaken to increase the water levels within Packard’s Heath compartment of Hatfield SAC and to stabilise water levels on Thorne Moors SAC in order to help in the restoration of this European rare habit lowland raised mire. This work is being undertaken as part of the Conservation Actions as part of the LIFE+ Project That’s’ Life (LIFE13/NAT/UK000451), Action C4 & C5 Peat was extracted from the site for many years but gained momentum when extracted commercially from the 1870’s until 2004, with surface milling taking place from the late 1980’s. The older cuttings that have not been subjected to surface milling and exhibit a baulk and cutting topography are higher than adjacent surface milled areas. As a consequence, they are also dryer and have led to the establishment of birch scrub. Project intervention: Remove birch scrub to facilitate the building of peat bunds within Packard’s Heath. Increasing water levels will eventually reduce the vigorousness of the remaining scrub, the water level will naturally rise due to reductions in evapotranspiration and water table management. The higher water table will then prevent the scrub from re-establishing. On Thorne Moors action is required to increase and stabilise water levels in various compartments within the Thorne Moors complex. Stabilising water levels should help increase the formation of peat forming Sphagnum mosses. Whilst our preference would be to have one supplier that can meet all our requirements within the deadline we recognise that this may not be possible. Therefore, the authority (NE) shall divide the specification into Lots covering the following work packages and as discreet works NE/Defra reserve the right to reduce number of packages depending on outcome of the procurement exercise:- Lot1 All Ground Works at Thorne Moors Lot2 Packard Heath – 415m x plastic piling and 1 x plastic dam Lot3 Black Drain 1 x Steel Dam with tilting gate Lot4 Combined 715m x plastic sheet