LAND AT MARSHMOOR, WELHAM GREEN (WEG4B) Infrastructure Appraisal - Final Gascoyne Cecil Estates 18/03/2015 Quality Management Issue/revision Issue 1 Revision 1 Revision 2 Revision 3 Remarks Draft Final Date March 2015 March 2015 Prepared by UKLJK001 UKLJK001 Signature Checked by UKMJI002 UKMJI002 Signature Authorised by UKMSF001 UKMSF001 Signature Project WSP Project 70010445 70010445 number File reference LAND AT MARSHMOOR, WELHAM GREEN (WEG4B) Infrastructure Appraisal - Final 18/03/2015 Client Gascoyne Cecil Estates Hatfield House Hatfield Hertfordshire AL9 5NB Consultant WSP UK Ltd 66-68 Hills Road Cambridge CB2 1LA Tel: +44 (0)12 2355 8065 Fax: +44 (0)12 2355 8051 www.wspgroup.co.uk Registered Address WSP UK Limited 01383511 WSP House, 70 Chancery Lane, London, WC2A 1AF Project: Dated: 18/03/2015 Gascoyne Cecil Estates Table of Contents 1 Introduction ............................................................................. 5 2 Existing Conditions ................................................................ 7 3 Proposed Transport Strategy .............................................. 15 4 Traffic Impact and Mitigation ............................................... 21 5 Sewerage and Wastewater Treatment ................................. 27 6 Flood Risk and Drainage ...................................................... 31 7 Utilities ................................................................................... 39 8 Conclusions .......................................................................... 45 Figures Figure 1 – Site Location Plan Figure 2 – Key Facilities Plan Figure 3 – Walking Accessibility Plot Figure 4 – Cycling Accessibility Plot Figure 5 – Bus Route Plan Appendices Appendix A – Illustrative Masterplan Appendix B – Road Traffic Accident Data Appendix C – Bus Routes Plans Appendix D – Preliminary Design of Proposed A1000 Dixons Hill Road Access Appendix E – TRICS Outputs Appendix F – Existing Catchment Plan Executive Summary Overview The Welwyn Hatfield Local Plan 2011-2031 identifies an overall housing need for 12,500 new dwellings in the Borough in the Local Plan period. The draft Local Plan consultation document outlines proposals for future development in Welwyn Hatfield including sites for new homes. A series of consultation events were held between the January and March 2015. Gascoyne Cecil Estates (GCE) has identified five key sites and is seeking their allocation in the emerging Welwyn Hatfield Local Plan. Ŷ Stanborough = 1350 dwellings (as set out in latest Local Plan consultation), and have tested the site for proposals for 1350, 1650, and then 2000 dwellings (maximum development scenario envisaged by GCE). 1650 represents the proposed development. The schemes have beeen tested to include a primary school and some local retail and community uses and medical centre, plus secondary school for 2,000 dwellings scenarios; Ŷ Creswick = 300 dwellings; Ŷ Ellenbrook = up to 100 dwellings, with safeguarding of land for longer term development of up to 400 dwellings overall; Ŷ Marshmoor = 270,000sqft GFA of B1 office / R&D, plus 120 dwellings; Ŷ Symondshyde = 1,100 dwellings plus primary school and local shop (250 sqm). GCE recognise that this level of additional housing will generate additional traffic, leading to increased congestion and this will place additional demands on key infrastructure. Initial infrastructure appraisals have been completed for each GCE site that consider some of the key requirements for the following: highways and transport; sewerage and wastewater treatment; flood risk and drainage and utilities. Building on the technical work completed to date for each site, the key focus over the next 12 months will be to take a pro-active approach, working with the highway and planning authorities, local residents and key stakeholders to ensure that appropriate mitigation strategies are agreed in principle for the key GCE sites, and are based on a credible and technically robust evidence base. It will be critical that the proposals for the sites are suitably progressed in order to meet the following key requirements: Ŷ Robust and deliverable and based on sustainable and sound proposals with a reasonable prospect for delivery; Ŷ Based on technically robust and credible evidence; Ŷ Have adequately considered the impact on the operation of the strategic road network and identified mitigation, where appropriate; Ŷ Have adequately considered the impact on the operation of the local road network and identified mitigation, where appropriate; Ŷ Have proposed enhancements to the transport network, including measures relating to sustainable transport options. A significant proportion of Welwyn Hatfield residents work locally but still use their car to undertake journeys to work and shopping, leisure and education trips. Over the next 12 months, in order that opportunities to travel by non car modes are maximised, we will consult with key stakeholders to develop and progress access and movement strategies, for each mode of transport, that aim to deliver greater connectivity, and seek to address barriers to movement in order maximise accessibility to non-car modes. This will be critical in helping to minimise journey lengths for employment, shopping, leisure, education and other activities, and for the self-containment of trips within the proposed developments and the surrounding area. Project: Dated: 18/03/2015 1 Gascoyne Cecil Estates Ultimately, GCE is of the opinion that significant Government led investment is required to deliver an integrated public transport system to serve Central Herts and, in particular, to address the lack of east- west connectivity across the county. GCE fully supports the development of a coherent plan for green infrastructure and the creation of a recognisable green corridor which, if delivered effectively along with well planned, mixed use and sustainable developments, has the potential to ensure that Welwyn Hatfield remains an attractive environment in which people still aspire to live, work and play over the decades to come. The proposals for a green corridor linking the principal settlements of Herford, Welwyn Garden City, Hatfield and St. Albans present a rare opportunity to deliver a coherent vision for the benefit of future generations. Infrastructure Appraisal – Land at Marshmoor Transport The location of the site and the above description of existing conditions indicate that the site has good accessibility by non-car modes to a number of local facilities. Both Hatfield and Potters Bar are within a reasonable cycling distance of the site, and a number of bus services pass close to the site. Fast and frequent rail services to London and Cambridge are also easily accessible from the site, which is located just south of the site boundary immediately adjacent to the railway line and the station. The capacity of the local highway network and its ability to accommodate the development is important, particularly on strategic routes and at key junctions which are likely to be affected by the proposed trip generation of the development. A key element of the approach of the development is to focus on providing only appropriate sufficient capacity for the most sustainable transport scenarios and resulting off-site trips. The development itself would implement suitable improvements to walking, cycling and public transport infrastructure, as part of a transport strategy for the site. A key aim will be to try and encourage a shift away from travel by private car relative to existing travel behaviour through the provision of new, improved and high quality alternatives and better public transport services. To this end the central focus point for the development will be integrated public transport services providing high quality rail and bus services linking the site with the local population and employment centres at Hatfield, Welwyn Garden City and Potters Bar, as well as public transport interchanges in both towns. The transport strategy set out focuses on a hierarchy of transport modes that promote sustainable travel by walking, cycling and public transport. Walking and cycling will be focused within and between the site and the surrounding area, and public transport will be focused between the site and the surrounding area. A key feature of the site is it’s close proximity to Welham Green Railway Station which is located just south of the site boundary immediately adjacent to the railway line and the station, and accessible via the railway bridge on Dixons Hill Road. Due to this close proximity there is significant potential to encourage the rail use for users of the site, being within a 5 minute walk or cycle from the site. It is recognised that both residents and employees will still potentially use the car to reach the surrounding area that cannot be reached by walking, cycling or using public transport, and as such a vehicle access strategy will be considered, along with local highway measures to improve safety and encourage walking and cycling, within and between the site and the surrounding area. The initial trip generation for the development was calculated using trip rates, and these were used to gauge baseline levels of trip generation and would be refined further within a TA to accompany a planning application for development on the site in due course. In order to determine the distribution of the proposed development trips Origin and Destination Journey to Work data was obtained from the 2011 Census Data for residents of Welwyn and Hatfield, and