Wet conditions slowed things down last week, but better weather has helped in the past few days and we’re seeing lots happening at T2 and T3 in particular. The T3 hardstanding is being built up with stone now, and the foundation has been largely excavated; the contractors are carrying out tests to check the strength of the soil to determine if they need to dig down any further.
The main pour for the T2 foundation went well last week, despite getting unlucky (again) with heavy rain on the day. The second small pour for the upper turret was happening yesterday, the surrounding area having already been backfilled.
At T1 the majority of the backfilling and landscaping has been completed too.
Meanwhile the saplings we’ve planted are doing well – I’ll leave you with some pictures of them along with some of the other plants blooming in the compartment.
Our second foundation pour will be next Thursday the 16th. From around 6am concrete deliveries will be heading up to site, and deliveries will continue throughout the day. Most deliveries should be completed by early afternoon, but final finishing and polishing is likely to continue into the evening, so some light vans may leave the site later than normal. Local residents may see some more lorries on the roads than usual, but for the last pour we monitored HGV movements carefully, and had no reports of lorries going the wrong way; they should all be following the usual approved route from the A1.
The T1 foundation has now been completed; there was a second small concrete pour for the upper ‘turret’ section which had to have new shuttering fitted around it after the main pour.
The wooden shuttering has been taken off and the foundation is being backfilled with some of the surplus subsoil and topsoil generated when the foundation was being excavated. This landscaping will mean that cattle will be able to graze right up to the base of the turbine towers once the site is operational.
At T2, the steel reinforcement is completed, and all that remains to be done prior to the foundation pour next week is to install the metal shuttering around the edges.
An earlier blog post described some of the planting we’ve undertaken at Wally Cleuch, which has the dual purpose of screening the blade tips from view from Oldhamstocks, and of enhancing the habitat for local species. We’ve also undertaken further planting works in and around the Hoprigshiels site itself to further improve biodiversity and wildlife habitats locally.
The first two parts of the planting works on site have now been completed. ‘Compartment A’ is a small glen which the Heriot Water flows through, to the north-west of our turbine 1. The first step was to erect a deer fence around this to protect the young trees from grazing damage. The deer fence has reflectors fitted to make it more visible to birds.
The planting here has been carried out by Borders Forest Trust under the supervision of our Ecological Clerk of Works. As at Wally Cleuch, Borders Forest Trust agreed a wide mix of different native species to be planted, including Alder (Alnus glutinosa) 15%, and Willows (Salix cinerea, S. pentandra and S. caprea) 10% in the wetter areas close to the burn, and on the drier better soils a mix including Sessile Oak (Quercus petraea) 25%, Downy Birch (Betula pubescens) 10%, Holly (Ilex aquifolium) 5%, Rowan (Sorbus accuparia) 15%, Crab Apple (Malus sylvestris) 2%, Wild Cherry (Prunus avium) 8%, Hawthorn (Crataegus monogyna) 5%, and Elder (Sambucus niger) 5%.
Further south on the banks of the Heriot Water, we’ve built twenty tree boxes. This is an area where the farmer grazes cattle, so instead of fencing it off entirely, the tree boxes will protect the new trees from deer and livestock. Alder and Sessile Oak saplings have been planted in this area. The tree boxes will provide new habitat for many plant, bird, insect and mammal species, and in the future as the trees mature, give good shelter to livestock grazing around them. Overall at Wally Cleuch and Hoprigshiels we’ll be planting a total of five thousand, eight hundred and ninety nine trees – nearly two hundred times as many trees as we’ve had to fell for the windfarm tracks, which were mostly stika spruce with low ecological value. This will mean a big net increase in carbon capture and biodiversity for the area.
Other benefits of the new native woodland, tree boxes and shelterbelt enhancements include reduced run off from the arable operations, a reduction in diffuse pollution reaching the burn, shelter for stock, and potential in the very long term for a small source of timber for fire wood once the trees are mature through the removal of the occasional fallen tree. Carbon will be locked up within the wood contributing to a reduction the levels of carbon in the atmosphere (alder is a nitrogen fixer providing additional benefits, increasing the fertility of the soils in the immediate areas), and all habitat enhancements will create new habitats for pollinators which are able to pollinate both the native species within the habitat enhancement areas but also to pollinate any maize, beans and other similar crops pollinated by insects planted at Hoprigshiels and also gardens in the nearby villages of Oldhamstocks and Cockburnspath , and the shelterbelt/hedge creation at Wally Cleuch.
The woodland areas and removal of 2.5 hectares from grazing will also help to reduce the potential for flooding downstream in periods of high rainfall. Immediate runoff can be reduced by up to 90% when woodland is planted along burns.
Further south again is Hoprigshiels wood, comprised mainly of mature Alder. Alder is not a particularly long lived tree (70 -150 years) and there are many ‘maturing’ Alder trees with very limited regenerating trees or saplings in the woodland. The plan here is for Borders Forest Trust to carry out come coppicing, cutting back some branches to the root to stimulate new growth. Coppicing will lengthen the life of the tree and to enhance the biodiversity and habitat value of the woodland coppicing two areas within the wood (totalling an area of 0.25 hectares) will encourage an increase in diversity within the woodland, both in terms of species using the woodland and also in terms of habitats and age structures of the coppice. The opening of the canopy will allow light through the canopy and onto the woodland floor. This will allow the development of a ground flora and dependant on the levels of browsing, a potential shrub layer. The regeneration of these layers will be encouraged by the disturbance to the soil due to the felling and extraction of the timber which will be carried out by chainsaw and a low impact method of removal such as tractor winch or horse logging due to the small size of the woodland. The young coppice shoots will provide a variety in the availability and structure of the cover providing new feeding and nesting opportunities for birds and habitats for a variety of insects and other small invertebrates. Some of the brash wood will be stacked against the coppice stools to protect the regeneration from deer browsing. This has shown to be particularly effective in northern England and allows coppice to get away from browsing pressure effectively and cheaply. The majority of the timber will be removed and used on the farm, with at least 25% left as timber piles within the wood to create a deadwood habitat, providing habitat for small mammals, birds, lichens and fungi, further enhancing the biodiversity of the area and whilst at the same time maximising the opportunity to bring the woodland back into management.
Lastly, there is one section of the existing shelter belt between turbines 2 and 3 where wet ground has caused some of the sitka spruce to blow over in the wind. In this area (compartment D), we’ll remove the fallen timber, and replant with native species that suit wet conditions such as Alder (Alnus glutinosa) and Willows (Salix cinera and S. caprea). These will continue to provide shelter once they are established and will be unlikely to suffer from windblow. We hope to carry out this final planting and the coppicing in the autumn.