Representation by Nick Miller
- Date submitted
- 17 July 2023
- Submitted by
- Members of the public/businesses
ALPHAMSTONE Submission to Inspectors July 2023 - Nick Miller BA (Biology), volunteer conservation advisor REQUEST FOR NATIONAL GRID’S APPLICATION TO BE REFUSED LWS = Local Wildlife Site, NG = National Grid In respect of biodiversity and habitat disturbance, where NG’s proposed powerline route crosses key habitat in Alphamstone (Sheet 27 of NG’s map of the route). I invite the Inspectorate to reject this application, on the grounds that it fails to present correct information on: 1) exceptional and important biodiversity, 2) an alternative preferable route, and 3) the true impacts of its engineering method. I present information to show that whilst NG have recognised the need for concessions to biodiversity and the landscape, they have in fact not made the necessary concessions. I argue that NG’s choice of route here is wholly arbitrary. I urge the Inspectors to require an independent re-assessment of the environmental impacts of NG’s technology options, before any further consideration of the application can be given. NG’s statement in their Autumn 2022 re-consultation is the key one, needing closer consideration: “We have made some further changes to our proposals. The biggest changes to the plans are in the western part of the Stour Valley, in the parishes of Lamarsh, Alphamstone, Twinstead, Pebmarsh and Little Maplestead.....Feedback from stakeholders expressed concerns about the proximity of construction activities to Alphamstone, as well as concerns around the impact on sensitive parts of the environment and footpaths. As a result, we...are proposing to change the route of underground cables between Moat Lane and the Stour Valley West cable sealing compound. To reduce the environmental impact of the construction of underground cables we are proposing to install a section of these underground cables....using trenchless construction methods....Instead, cables will be drilled horizontally underground, beneath the landscape. This will protect the vegetation, watercourse and landscape in this area.”. The following are representations made to NG during 2022, mainly during the 2 public consultations, together with some further detail for clarification. I have made my own surveys, and have received important information from local residents Nigel Morgan, John Dumont and John McGlashan, as well as Nightingale survey information from Martin Peers, and Dormouse survey information from Suffolk Wildlife Trust (on behalf of Essex Wildlife Trust). 1 BIODIVERSITY: Natural England’s MAGIC map shows that the Alphamstone area is a link in an exceptional richness of wildlife habitat, by Eastern England standards. The exceptional area of connectivity, between Lavenham and Great Tey, is the biggest between the Coast, Brecks and Fens (National Habitat Network All Habitats Combined). It would be a strong candidate for a key role in a Nature Recovery Network. NG’s proposed powerline route crosses the A Meadows Local Wildlife Site, which is one of an exceptional group of ten Local Wildlife Sites, plus other nature reserves, that are virtually adjacent. Hence it will be seen that whilst NG have recognised the need for concessions to biodiversity, they have in fact not made the necessary concessions, nor justification for crossing an Essex Local Wildlife Site.. 2 ALTERNATIVE ROUTE: NG have shown no evidence of evaluating a suitable alternative route at Alphamstone. I the 2022 consultation, NG were provided by Nigel Morgan with an evaluated route to the south of Alphamstone, which crosses arable fields. Given the biodiversity on NG’s proposed route, combined with the great difficulties of their proposed trenchless construction, it seems wrong that the application gives no reasons for rejecting the southern option. The special and scarce qualities of this area, need to be appreciated. It’s in the Candidate Area for the AONB Extension, which the Dedham Vale AONB Team has applied for. The steep and sandy valley-sides are the reason for this landscape’s many scarce features, such as small fields and woods and limited arable farming, which make them so valuable for biodiversity. The landscape typology shows this area is part of the scarce, high quality and extremely attractive “Rolling Valley Farmlands” which differs hugely from both the valley floor (“Valley Meadowlands”) and the arable plateau (“Ancient Rolling Farmlands”) which both have wider panoramas but little variety of scenery and generally much lower wildlife value. This valley-side landscape is also found at Sprotts Farm Polstead (Sheet 13 of NG’s map of the route), where NG diverted their line through the arable surroundings, and it would be irrational in Alphamstone’s case not to similarly choose a route across arable land. Hence it will again be seen that whilst NG’s have recognised the need for concessions to the landscape, they have in fact not made the concessions that the southward diversion would have afforded. 3 ENGINEERING: Contrary to NG’s claims, tunnelling/boring is far from harmless to the land, but would cause short-term and long-term damage. In the case of the route through Alphamstone, the damage caused by undergrounding would be worse than a line of pylons. In their autumn 2022 consultation, NG state: “trenchless construction methods....Instead, cables will be drilled horizontally underground, beneath the landscape. This will protect the vegetation, watercourse and landscape in this area", however I ask the Inspectors to consider that NG’s information is incorrect technically, and I set out detailed information in the Appendix below. NG have failed to give any justification for choosing its A route, rather than the southern option to which any of its technology would be suited. 4 APPENDIX 1: BIODIVERSITY DETAILS: From this information I believe it will again be seen, that whilst NG have recognised the need for concessions to biodiversity and the landscape, they have in fact not made the necessary concessions. I invite the Inspectors to require an independent re-assessment of the environmental impacts of NG’s technology options. Though it can be discerned on NG’s maps, NG fail to say that their route occupies most of the A Meadows Local Wildlife Site, together with the Brook, and important adjacent peaty and spring-line and marsh habitats which are scarce in Eastern England. All of this land probably meet the definition in the NPPF Glossary of “Irreplaceable Habitat”. This is a perfect set of classic features, in Suffolk & Essex largely restricted to the mid- Stour Valley tributaries, resulting from its peri-glacial history, where sand overlays clay and the spring-line is botanically rich, and exceptionally damp habitats for Eastern England. The Brook and surrounding natural grassland give very important connectivity to this precious spot, which sits among an exceptional number of scheduled wildlife sites. The Essex Wildlife Records citation reads: “Bra240. Alphamstone Meadows (4.3 ha) TL 876360, This exceptionally rich site comprises wet meadows, dry slope grassland and sedge/rush marsh. These habitats support a rich flora amongst which Marsh Marigold (Caltha palustris), Common Spotted Orchid (Dactylorhiza fuchsii), Marsh Horsetail (Equisetum palustre), Ragged Robin (Lychnis flos-cuculi), Creeping Jenny (Lysimachia nummularia) and Bog Stitchwort (Stellaria alsine) are of particular interest as species typical of a rare and declining habitat. Selection Criteria: HCr11, HCr23, SCr13”. Table 7.8 has “Alphamstone Meadows LoWS would be crossed by an underground cable using trenchless installation techniques at this location. This area does not require a vehicular temporary access route. Pedestrian or light goods vehicle access would be permitted only. All habitat within the Order Limits would be retained” and the site shows on Sheet 27 of NG’s map. However, NG state in “APP-075 6.2.7 ES Chapter 7 Biodiversity”: “LoD have been designed to avoid sensitive ecological features where they do exist”. Local Wildlife Site is of course a recognised designation in normal district planning authority rules, which require that developments should not adversely affect Local Wildlife Sites. I supplied NG’s 2022 consultation with details of the numerous key species & habitats on their route, for instance there are numerous badger setts on the Local Wildlife Site here, and Otter spraints have been found by the Brook. Their revised route thankfully respects the Pyramidal Orchids and Lesser Calamint adjacent to the Local Wildlife Site, but not the Local Wildlife Site itself. Other species on the route include Tawny Owl, Bullhead, and extensive Wild Garlic, Marsh Marigold, Giant Horsetail and Golden Saxifrage, and adjacent are exceptional numbers of Dormice and Nightingale. I will refer to 2: Dormouse and Nightingale. Dormouse: the number of Dormouse locations recorded here in 2002 are not the 5-6 stated in the planning app, which were found by NG’s ecologists in the west of the area, but 14-15, since 9 were found by the Essex and Suffolk Wildlife Trusts’ Dormouse Project (detailed in the 2022 records they’ve sent me). A County Mammal Recorder has advised me a population this size is exceptional and important. The latter 9 were found very close to the present proposed route. Nightingale: Alph has long been a major refuge of Nightingale, while other sites in this part of the world have lost their historic populations. Five or more Nightingale territories have always been usual at Alphamstone centred close to where the route crosses the Brook, and more in the immediate area. Several people have provided me with map grid references. It has also seemed that the birds arrive in season as a group. Records at a place on the proposed powerline route include from 2022. In 2023 and previously, either 4 or 5 were calling from close to the route. Clearly Alphamstone is exceptional among conservation areas in Essex & Suffolk, and remains as an outstanding refuge of Dormouse & Nightingale, while other sites have lost their historic populations. Therefore I ask the Inspectors not to accept statements in NG’s Chapter 7 Biodiversity document (application document 6.3.7.8): “7.5.72: Five dormouse nests and one dormouse found in Area 10d (woodland north-west of Alphamstone) in Section G: Stour Valley in September 2022. 7.5.73: The results did not suggest that any one particular survey sub-site was of high conservation value for dormouse. As such, the presence of dormouse in the study area is representative of the known dormouse population status in the region and is valued as medium, as they are of county level importance.” “Biodiversity Net Gain” can hardly be applicable to Alphamstone with its LWS and other Irreplaceable Habitat, and I also ask the Inspector to consider that even records just outside the route, strongly indicate the exceptional importance of the connectivity, isolation and unspoilt character of the Alphamstone route, which are rarely matched even in the Stour Valley area. Such an exceptional area of wildlife cannot be considered piecemeal, without considering harm to such an integrated landscape. I ask the Inspector to consider that this is another reason to route the powerlines through arable land to the south of Alphamstone, and b) to consider I ask the Inspector to consider that this is a very strong reason to route the powerlines through arable land to the south of Alphamstone. 5 APPENDIX 2: Trenchless and other construction methods. This information has been supplied to me by Nigel Morgan MIET. It shows that NG are misleading when they state that trenchless construction “will protect the vegetation, watercourse and landscape in this area”. In view of NG’s admission that the Alphamstone section of the route needs safeguarding, and that comparison between the 4 methods (of pylons, trenching, trenchless, or trenchless with superconducting cable) is complex, I invite the Inspector to reject, in favour of either an independent technical report, or re-considering a route across arable land South of Alphamstone. If either the Southern Route with conventional cabling, or NG's present route with superconducting cable seems necessary, it should result in NG's submission being refused in its present form. Nigel Morgan’s information: NG seem to have given no information as to whether they have considered or evaluated the southern route option. I did get the impression that they had considered it internally, but they did not then explain their reasoning why it had been rejected. Undergrounding a double-circuit 400kV overhead line requires 18 separate cables to be buried, irrespective of method. A very wide extent of cables, or trench, and a very wide area of considerable vehicle damage, arises because the width of either the open trench method or the HDD method is related to getting rid of the heat emitted by the cables which is quite demanding because the ground is not a good conductor of heat. The HDD method requires a wider swathe because it goes deeper under the trees etc. The trench method, being closer to the surface emits the heat more easily so doesn't need to be quite so wide. But of course at up to 100m in total it is still far wider than would be required by a superconducting cable (only c.1m) because that doesn't emit heat. Of course this doesn't matter if the land traversed is agricultural. At the start and end of the HDD section a huge wide hole has to be dug for the boring machine to be inserted to start the bored section. Big diggers required for this I think. Even on NG's chosen route, your wildlife concerns would be very greatly alleviated if the chosen technology was to be superconducting cable. I think one could also take issue with the quantity of foreign material (not just the cables themselves) to be introduced into the ground in sensitive areas, particularly by trenching. I've worked out that a (say) 4km length of trenched cable (ie 18 parallel cables in 6 trenches each containing 3 cables) would involve putting into the ground something in the region of 33,000 tonnes of CBS (cement bound sand, which you or I might better think of as concrete) plus a layer of actual concrete tiles. I can hardly believe this figure, but keep looking at the maths and cannot yet see that I'm mistaken. If you want to check let me know and I'll send you the spreadsheet. CBS is a special material in which NG encase the cables to help dissipate their heat to avoid them developing hot spots which could arise by virtue of the variable thermal conductivity of the ground through which they are laid. So this is not really a "green" approach towards areas which have in the first place been designated as sensitive. However worse is to follow ... Because of the heat they generate, the cables' insulation - a type of plastic - degrades over time. So NG don't plan for these cable to last more than 40 years. But the trouble is that when their time is up, it seems to me that it will then be hugely expensive and virtually impossible to remove or replace them (I don't think ducts are used within the concrete which could facilitate replacement). Pylons seem to be ok after 60 - 70 years with more life left in them after that to the extent that they are now being re-wired for >100 year lives. There doesn't seem to be a similar possibility of life-extension for trenched cable so presumably they will just be abandoned and some new route churned up and similarly concreted elsewhere. The beauty of the superconducting cable approach is that, being run at a temperature of minus 200ºC, the plastic insulation is expected to greatly outlast that of conventional cables if not to last for ever. Also, because of the absence of heat, they could be put in ducts and therefore would be able to be replaced if ever needed. NG did not go out to tender for a superconducting cable option which I had asked them to do. Such a solution installed along roughly their present route would of course be very much less damaging to wildlife than what is currently being proposed.