Keep Manadon Moving - The PTP response

Plymouth City Council are currently undertaking a consultation on a road widening scheme at Manadon roundabout. The scheme which they hope to start in a few years is predicted to cost around £156 million.

Plymouth Tree People have formally responded to the consultation, details of which can be found here. The consultation is running until 24th June.

Here is the submitted response:

Manadon Roundabout Proposals

I am writing on behalf of Plymouth Tree People (PTP) concerning the proposed improvements to Manadon Roundabout and the surrounding roads. I have read all the information put out as part of the consultation process and Plymouth Tree People have these comments to make. 

It is important to recognise at this stage that these are preliminary views based on the information we have now. After our Plan for Trees meeting on Manadon, and as plans become more detailed, we would expect many of these concerns to be addressed. Although other issues may arise once details emerge.

PTP acknowledges that major changes will result in some loss of trees. I note that a 3-for-1 replacement is proposed. There is no indication of the scale of tree loss which is important as any significant removal of trees would impact on canopy cover for the area. Currently the area ranks high on Tree Equity score of 95% and low on pollution, removal of a considerable number of trees would adversely affect both scores.

The 3 for 1 replacement overlooks the "value" of certain individual trees or groups of trees. The scheme area may contain late mature, veteran, and ancient trees, all of which hold significant socio-economic and environmental value. Without more details, I cannot determine if the trees are inside or outside the scheme. Some of these trees are irreplaceable and must not be removed, even if that results in that part of the scheme being significantly modified or even cancelled. We would propose that the schedule indicated in table 28 of the Joint Local Plan Supplementary Planning Document should be the baseline for tree replacement (not a blanket 3 for 1 formula) but that the position and value of replacement trees to mitigate noise and pollution (both at planting and when fully grown), could be factored into this table. 

Outside of the most valuable trees there is an area designated as ancient woodland. Parts of it are also wet woodland which is a priority habitat and particularly unusual in an urban area. Modifications to the hydrology within the wet woodland or the surrounding wetland area should be strictly avoided, especially as this could also negatively impact Ham Woods which has statutory designation as a Local Nature Reserve. The requirements of the Joint Local Plan Supplementary document regarding 15m buffer zones, avoidance of harm etc should be the minimum protection required.  The current proposals for an “accessible green space” on the fields by Trevegaenue Gardens are a grave concern. During one of the consultations, a presenter mentioned that the area would be drained to improve access. However, another presenter indicated that water retention would be maintained, potentially using a scheme similar to Trefusis Park. In one of the artists impression diagrams the area was largely planted with trees. It was also indicated that a portion of the additional road runoff would be diverted to this area. Any modifications to this area should be implemented gradually with careful monitoring over an extended period before considering additional changes. With the option of undoing changes should they prove to be detrimental to the ancient woodland / wet woodland. This area currently functions as a Sustainable Urban Drainage System (SUDS) for Ham Brook, an important watercourse through Ham Woods LNR that supports various fish species, including the red-listed European Eels. Ham Brook has caused flooding issues at Weston Mill village in the recent past, this has been helped by the environmental flood management schemes in Ham Woods and it would not be acceptable for this scheme to increase the flood events in Weston Mill village.

The scheme could affect a significant number of mature trees, many of which were planted when the Manadon flyover was constructed in the 1980s. At 45 years old, these trees are now becoming particularly important for control of air pollution, as a significant sound barrier and a significant contribution to canopy cover in this part of the city. In addition, there are trees located in private gardens of properties that are likely to be subject to compulsory purchase. These trees may have been strategically planted to serve as a sound and pollution barrier. Given the provisional nature of the scheme, it is challenging to determine the exact number of trees at risk. However, the removal of a significant number of these trees could negatively impact the quality of life and health of many households. In this instance, implementing a 3-for-1 replacement policy will not be advantageous because the value of these trees lies not in their age, species, or form, but rather in their positioning and the grouping that creates an effective barrier. It is essential that these natural barriers are retained or replaced with a similar natural barrier both as a noise reduction measure and to ensure that effects of traffic pollution is reduced.

The Meavy Way component of the scheme is less developed compared to the main scheme, and therefore, the changes are still largely undetermined. There are however a few significant trees (and one particularly significant beech tree) which could be at risk of changes in this area. We would appreciate early discussions regarding the proposals for this route as they become better defined.

Dave Curno

PTP trustee