Strategic Environmental Assessment (SEA) for the Shenley Park SPD

5. Defining reasonable alternatives

Background

5.1 Work on concept masterplan alternatives has been undertaken over a period around one year and has involved extensive engagement with stakeholder organisations as well as a range of technical evidence gathering workstreams.

5.2 The 'design evolution' is explained in detail within the Baseline Evidence and Design Analysis (DLA, June 2023), which considers a wide range of issues and options before concluding that the key choice, at the current time, is in respect of "access + movement" – see Figure A. In particular, the key choice is judged to be in respect of the required link road through the site. More specifically, the key choice is regarding whether there should be: A) an external road link that acts as a strategic link; or B) an internal link road that acts as a 'street'. With regards to (B), there is then a supplementary question in respect of whether there is additionally land reserved for a future strategic / grid road connection. The conclusion of the DLA work is that attention focuses on Scenarios 2 and 3, but that Scenario 3 is ultimately preferable.

5.3 For other masterplanning issues the report concludes that there is a clear preferred approach at the current time (i.e. for consultation), in light of the available evidence. However, for the purposes of the SEA process / this Environmental Report, it is considered appropriate to 'take a step back' and consider more high-level concept masterplan alternatives, as discussed.

Figure 5.1: Tightly bounded concept masterplan alternatives varying only in respect of approach to 'access and movement', as defined within the DLA Study (June 2023)

Reasonable concept masterplan alternatives

5.4 The reasonable concept masterplan alternatives were defined following a stakeholder workshop held in April 2023. The decision was taken to define concept masterplan alternatives with a view to enabling particular consideration of / discussion around the following key issues:

• Archaeology – extensive work has been undertaken to consider a key archaeological constraint affecting the central-eastern part of the site, namely evidence of a Roman settlement. This culminated in a Cultural Heritage Impact Assessment (CHIA, Oxford Archaeology, 2023) which confirmed that the settlement is of local significance and, in turn, recommended that it does not necessitate preservation in situ (i.e. it can be excavated, recorded etc). However, in order to further bolster the evidence-base behind this approach, it is considered necessary to test the option of avoiding development over the archaeological site.
   
• Southern half of the site – Shenley Park is "a site of two halves", with fewer constraints to development in the northern half (a fairly uniform plateau landscape) relative to the southern half (a more varied / intricate valley landscape). There are clear arguments in favour of at least some development in the southern half, including mindful of the road connectivity, with the VALP policy requiring a new link road passing from the A421 (at the southern edge of the site) northeast through the site to join the MK grid road network (H6 and/or H7). However, there is also feasibly the option of nil growth. The assumed implication is a need for commensurately higher growth in the north, as opposed to lower growth overall (see below).
   
• Green infrastructure – numerous elements of the green infrastructure strategy are now very well established (or even a 'given'). Notably, and as shown in Figure 5.2, it is well established that there is a need to: protect existing green infrastructure around the edge of the site and along Shenley Road; deliver a landscape / greenspace buffer to Whaddon and deliver an extension to Tattenhoe Valley Park along the valley bottom within the southern part of the site. However, a key matter potentially remaining open to consideration is in respect of the size of the landscape / greenspace buffer between the site and the historic hilltop village of Whaddon.

5.5 The above considerations led to the definition of four reasonable concept masterplan alternatives, namely:

1. The emerging preferred option (the basis for the DLA scenarios)
2. As per Option 1, but with the Roman settlement area left undeveloped
3. As per Option 1, but with the southern part of the site left undeveloped
4. As per Option 1, but with a much larger Whaddon buffer and, in turn, an additional residential parcel in the south (west of the link road).

5.6 Finally, with regards to growth quantum, all options are assumed to deliver at least 1,150 homes in line with VALP Policy WHA001, and mindful of the importance of delivering on the committed VALP land supply. Further context is that the site promoter submitted an EIA Scoping Report for an up to 1,650 home scheme in 2022, although the latest developer proposal is for a 1,265 home scheme (see shenleypark.consultationonline.co.uk).

Figure 5.2: An early sketch of key masterplanning priorities / parameters

Figure 5.3: The high-level concept masterplan 'reasonable alternatives'