Topic DISTRICT LDF Creating Sustainable Paper Communities Addendum Revisions to take account of Issues and Options Consultation results

Flooding

February 2008 TOPIC PAPER - FLOODING

SUPPLEMENTARY REPORT

Executive summary

This report represents a supplementary paper to Topic Paper 9 - The economy and employment. This has been produced to respond to the consultation on the Issues and Options Paper ‘Salisbury and South – Our Place in the Future’ which was consulted on for a 12 week period during the summer and early autumn of 2007.

The paper firstly analyses the results to what we asked the public specifically within the Issues and Options Paper ‘Salisbury and South Wiltshire Our Place in the Future’ with respect to flooding , then continues to look at relevant individual comments that were made to ascertain whether there were any additional areas that needed looking into to take forward into the preferred options and then identifies some preferred options.

Introduction, purpose of document and context. This document is the second element of the series topic papers that were published in order to present a coordinated view of the assessment of the evidence upon which we based our Core Strategy Issues and Options consultation. In order to make it easier for stakeholders to understand how we had reached our conclusions and as a key part of identifying the challenges facing our district and feasible options for addressing them, a series if 16 topic papers were written. These were as follows:

• Topic 1 - Climate Change • Topic 9 - Economy

• Topic 2 - Housing • Topic 10 - Tourism & Leisure

• Topic 3 - Settlement Strategy • Topic 11 - Planning Obligations

• Topic 4 - Supporting Communities • Topic 12 - Waste & Pollution

• Topic 5 - Biodiversity • Topic 13 - Conservation

• Topic 6 - Flooding • Topic 14 - Design

• Topic 7 - Agriculture • Topic 15 - Transport

• Topic 8 - Retail • Topic 16 - Inclusive Design

The Issues and Options that were identified within the topic papers formed the basis for the consultation document, “Salisbury and South Wiltshire, Our Place in the Future”. This document represented a 'joined up' consultation exercise incorporating questions relevant to the Community Strategy and Salisbury Vision, as well as the LDF Core Strategy Issues and Options. This document was the subject of consultation for 10 weeks between the 26th July and 5th October 2007. Over 50 public events were undertaken, to promote the process, and over 5,000 responses were received. Review of Original Topic Papers The next stage in the process is to review the initial evidence base in the topic papers and update where necessary and analyse the results of the consultation to formulate a set of preferred options. Where factual errors, anomalies or areas requiring clarification have been highlighted by the consultation, then these changes have been indicated on the original topic papers to show their evolution.

Analysis of Results of the Issues and Options Consultation The next stage in the process is to review our analysis of the evidence base within the topic papers to take account of the outcome of the consultation and also update them where there has been a change in the evidence available to us since their publication. This review of the topic papers is an essential step on the road to producing the Core Strategy Preferred Options paper, which builds on the response of stakeholders to the issues and options we presented in the 'Our Place in the Future' paper.

Assessing the Local Need - Why Are We Developing Policies on flooding? The need for this topic to be included within the emerging Local Development Framework has emerged clearly from an analysis of national and regional planning policy and an appraisal of the growing body of specialist literature and guidance given to local planning authorities. Furthermore original work that has formed part of the base of evidence which will inform the Local Development Framework process has highlighted that there is a need for a new and effective set of policies to help meet our objectives.

What are we trying to achieve - what are our overall objectives? The core objectives as envisioned at the outset of this project were to develop a set of planning policies, which contribute to the following patterns of land use:

• social progress which recognises the needs of everyone • effective protection of the environment • prudent use of natural resources • maintenance of high economic growth and employment

On a more specific level the desired outcomes at the outset of this project were: • Via Strategic Flood Risk Assessment (SFRA), to map all forms of flood risk and use this as an evidence base for the LDF to locate new development primarily in low flood risk areas (Zone 1). Elsewhere, the Sequential Test is required for land use allocations and, where necessary, the Exception Test. • Prepare appropriate policies for the management of flood risk; • Inform the sustainability appraisal so that flood risk is taken account of, when considering options and in the preparation of strategic land use policies; • Identify the level of detail required for site-specific Flood Risk Assessments (FRAs);

Taking A Spatial approach It would be a crude mistake to develop a set of policies which are based on a 'one size fits all' premise. South Wiltshire is a rich and varied part of the Country and the issues and challenges within it vary from place to place. For example, is it the case that the demand for affordable is uniform across the area or does it vary between settlements and should our policies reflect this. We feel that they should and this way we should produce spatial strategies that are rooted in the distinctive character of specific places and are tailored to solving their particular sets of problems. This is in a nutshell for us, what spatial planning is all about.

One of the drawbacks we have encountered in the past is that of plans and strategies being delivered over disparate areas, when it makes much more sense from the customers perspective to have them coordinated and covering the same areas. This is often called co-terminus service delivery and is based on joining up services and policy solutions so that they are more tailored to where they are needed.

To align our policy solutions to the areas where the issues are arising, we have taken a detailed look at how the diverse character of our district and assessed if there are broad areas which share similar characteristics and present similar sets of challenges. The Wiltshire community areas were defined in the early 1990’s in response to a review of local government boundaries that set greater store by ‘natural’ communities, i.e. areas that described real patterns of local life (shopping, employment, schooling, etc.) as opposed to administrative boundaries.

A number of dimensions were used to define these areas of local life including:- secondary school catchment areas, local convenience shopping patterns, postcode town boundaries, pre-1974 urban and rural district council boundaries, housing market areas, journey to work catchment areas, a historical study of patterns of local life by local historian, Dr. John Chandler, and the local geology/topography of the county. Six of Wiltshire’s twenty community areas are in Salisbury district, namely: • City community area

• Four Rivers community area (also known as Wilton area)

• Mere community area

• Nadder Valley community area (also known as Tisbury area)

• Southern community area (also known as Downton area)

• Stonehenge community area (also known as Amesbury or Northern area)

On analysis the justification for the Community areas appears just as valid today as it did when they were formed, being as they were based on a sound understanding of the hierarchy and function of settlements and how communities view their sense of place. Furthermore the issues and challenges identified do reflect the similarities within these existing areas and also the diversity between them.

However there is lilted point in rigidly sticking to a spatial pattern of interpreting the District if it is not appropriate to certain issues or challenges. For example the Military issues reach outside of the District to the north of the plain and similarly there is a huge synergy between Wilton and Salisbury. Therefore while, where appropriate the Community Plan areas will form the basis of our spatial model, it will not be pursued dogmatically so, and where the functional relationship between places dictates we will promote a flexible approach. In other words the areas defined by the community plans should best be considered as soft verges rather than cliff edges.

FINDINGS OF THE 'OUR PLACE IN THE FUTURE' CONSULTATION ON THE CORE STRATEGY ISSUES AND OPTIONS

What did we ask? Questions relating to flood risk were asked under the following sections of the “Our Place in the Future” consultation:

• Community Priorities • Community Satisfaction • Issue 11 “Facing challenges such as flood risk, waste and reducing pollution and providing transport choices”

More general questions relating to Climate Change were also asked in various parts of the questionnaire and these are related to below.

Summary of responses It was made fairly clear in the consultation, particularly in the Flooding Topic Paper, that national and regional policy, the evidence base, and common sense imply a fairly clear course of action in respect of flooding. In essence this is to gather all necessary and relevant as to flood risk, and to divert development wherever possible to zones of lower risk, and in addition planning policies and development control decisions should prevent development from increasing the risk of flooding elsewhere. Full criteria and parameters are set out in PPS25.

Against this policy background there is effectively no scope for consultee response to allow us to deviate from this overall approach, other than in refining particular elements, particularly mitigation methods, and applying national criteria in a way particularly distinctive to the area.

• Community Priorities and Satisfaction

Within the consultation, 19 separate areas were put forward, including health, education and housing, with the public invited to state which were the biggest priorities as they see them. From the householder-mailed survey, over 5000 responded, and “Tackling Flood Risk” emerged overall as 11th in terms of the mean overall score given1. In the full consultation document, around 400 respondents indicated a view, and this issue emerged at a similar level of 12th most important priority issue. In terms of satisfaction with the issue as currently dealt with, this was only asked within the full consultation questionnaire, and Flood Risk emerged as 8th of 19.

• Issue 11 “Facing challenges such as flood risk, waste and reducing pollution and providing transport choices”

Within this issue it was noted that we should assess the flood risk associated with new development and quite unsurprisingly the overwhelming majority (97%+) agreed.

1 This was in the format of marks out of 10. Spatial analysis of results

Implications on a district-wide or wider area

The overall result of the consultation therefore is that flooding is considered a middle- ranking issue within the context of overall district priorities. It is possible that it emerged more highly as an issue due to the timing of the consultation, shortly after some severe flooding events across the UK in June and July 2007, and these events were referred to by a number of people in the consultation. Rivers and their floodplains, owing to local geography, are however a very present feature within Salisbury district and are a clear concern to many people.

In addition to Salisbury being at the “hub” of the district’s floodplains, all of the proposed Local Centres within the district are partly within or adjacent to an area in flood zone 3a or 3b (“high probability” of flooding, and “functional floodplain” respectively). This derives in large part from the characteristic settlement pattern of the area with many settlements in the valleys. In addition, “Main villages” partly within zone 3a/3b include Hindon, Shrewton, Porton, Winterbourne Dauntsey/ Earls/Hurdcott. Flood zones also affect many of the district’s smaller villages and hamlets.

Implications for the six community areas The section below are “non-scientific” observations on the spatial implications of the findings of the recent Strategic Flood Risk Assessment. Precise mapping of these zones and other factors including climate change modelling of future flood zones, and historic flooding events, is available for public view.

Mere and District

This community area is somewhat geographically and topographically separate from most of the district and its drainage is primarily to the Stour. Its settlement pattern differs somewhat from much of the district with there being less distinctive river valleys. Flood zones 3a/3b within this area tend to be far narrower here than elsewhere.

Local centre: Mere Within Mere a small ‘corridor’ of flood risk exists in connection with Shreen Water, a tributary of the Stour. This area of risk starts close to the A303 and leads through the eastern part of the village and affects a relatively small number of properties.

Main village: Zeals The elevation of Zeals relative to the drainage pattern puts it entirely within the Zone 1, “Low” probability area.

Cluster villages: No ‘clusters’ were proposed within this Community Area

Elsewhere Although several rivers and tributaries in the area are associated with high risk of flooding this is almost entirely limited to agricultural land and no significant development is close to higher risk zones.

Nadder valley The drainage pattern within this Community Area is (entirely expected) almost entirely associated with the Nadder and its tributaries and most of the larger settlements are within close proximity to flood risk areas. The historic pattern of growth has naturally avoided the flood plains themselves, however access through the area may have the potential to become difficult in more significant flooding events as access to many settlements is via minor roads which are partly within the higher flood risk areas.

Local centre: Tisbury Tisbury is situated close to the convergence of several tributaries with the Nadder each of which has an associated flood zone 2 and 3. Zone 3 extends to a width of over 100m in areas adjacent to the village south/south-east of The Avenue. Elsewhere however, owing to the relatively steep topography, areas of flood risk are narrow and affect a fairly small number of properties, and not the retail and service centre of the village. The railway station and Station Works site are directly adjacent to, though not within, the flood plain.

A 2007 Avon model exists for Tisbury which involved the development of detailed hydraulic models and the production of flood maps for the 1 in 100 and 1 in 1000 year return period without defences, however more detailed Flood Risk Assessment is recommended in the event of allocations being considered.

VARIATION IN FLOOD DEPTH FOR THE AT TISBURY. SOURCE: SFRA 2007

Main village: Hindon A very small number of properties are affected by a very narrow area of flood risk associated with the stream running west-east through the southern part of the village centre

Cluster villages: Ludwell, Donhead St Andrew, Donhead St Mary, Charlton. The pattern of development in this group is closely influenced by the topography of the upper Nadder, however very few properties are in the high risk area.

Elsewhere Elsewhere within this Community Area the villages of Chilmark, Ansty, Swallowcliffe and are particularly closely related to upper streams around which higher risk flood zones have been identified, however again the overall number of properties at risk is low.

Stonehenge This community area includes much of the river Avon upstream of Salisbury, as well as the tributaries Bourne, Till and Nine Mile River. Unlike the Nadder area, other than these there are few smaller tributary streams with an associated high flood risk.

Northern urban cluster: Amesbury, Bulford, Durrington These three settlements are adjacent to the river Avon. As elsewhere the built area is overwhelmingly within the low risk area. However, development in and around these settlements (whether in or beyond the flood risk area) should be particularly sensitive of the need not to increase flood risk downstream. Measures such as SUDS will be particularly important.

Main village: Shrewton Shrewton together with Orcheston are in the upper reaches of the Till and there is a relatively large area in the village within flood zone 3.

Bourne Valley All of the villages in the Bourne Valley are in close proximity to areas at high risk of flooding. In terms of the “Main villages”, Porton is segmented into two main parts by the river Bourne, where there is a fairly broad high risk flood zone (100m+). At Winterbourne Dauntsey / Earls / Hurdcott, development is almost entirely to the east of the river Bourne, where the flood plain has similar characteristics to Porton though is in close proximity to a greater number of dwellings.

Elsewhere Flood risk areas surrounding the river Avon affect all settlements in the Woodford Valley. However, as elsewhere, the total number of dwellings directly within the flood plain is fairly low.

Four rivers: Ebble, Nadder, Wylye, Till. The areas of flood risk within this Community Area are relatively extensive compared with the areas noted above. Zone 3 around the Wylye and Nadder is typically 300m in width, becoming 600+m across where they converge. The Ebble is a much smaller tributary.

Local centre: Wilton Wilton is well known as facing problems relating to both flooding, drainage and sewage. It is at the convergence of the Wylye and Nadder and much of the historic centre of the town is within or adjacent to higher risk areas. More recent, particularly 20th century, housing areas are in low risk areas. However any development, similarly to Amesbury/Durrington/Bulford, would have to be particularly mindful of downstream impacts on Salisbury, and thereafter Downton, and mitigatory measures such as SUDS.

Main village: Dinton Dinton is entirely within the low flood risk area.

Cluster villages: Great Wishford, South Newton, Stoford. Though ‘valley settlements’ there are few properties within the higher risk area, mostly in South Newton.

Elsewhere Within the Ebble (‘Chalke’) Valley, settlements including Bowerchalke, Broadchalke and Bishopstone are characterised by a linear nature in close harmony with the watercourses, which are associated with higher flood risk categories although these zones are very narrow.

Southern The Avon is the main river within this area, contributed to by the Ebble. A sizeable part of the area however drains south-eastward toward the river Test. Most of the larger settlements are within the Avon valley itself including Laverstock, Alderbury and Downton.

Local centre: Downton Downton is a known location of significance for flooding and the Environment Agency has implemented a defence scheme to address this in respect of existing properties. However to the north and south of the historic core of the village are extensive flood plain areas which has led to most modern development taking place to the west and east, on higher ground.

VARIATION IN FLOOD DEPTH FOR THE RIVER AVON AT DOWNTON

Alderbury The built ‘envelope’ of Alderbury is in areas of low risk although outlying properties toward Petersfinger are in close proximity. Local concerns were raised in Alderbury in respect of the A36 Southampton road which is the route into Salisbury, which is at some flood risk.

Laverstock Laverstock is closely defined by the lower Bourne, which acts as the boundary with Salisbury. In places the higher risk is 200m+ in width however most development is well clear of the functional flood plain.

Whiteparish, The Winterslows, Morgans Vale, Woodfalls, Redlynch, Lover, Bohemia These settlements are not within or adjacent to higher risk flood zones.

Elsewhere Settlements in the lower Ebble valley including , Homington, and Nunton are in close proximity to the higher risk flood area however only in Coombe Bissett are there significant numbers of properties within or adjacent to zone 3. Britford is effectively encircled by functional flood plain. Elsewhere, there are known localised flooding issues for instance at Pitton which flooded in 1995. West Dean is bisected by a high-risk flood area.

Salisbury City The most frequent comments received on the subject of flooding related to Salisbury itself, which in addition to being the focus of development, is also the ‘hub’ of the flood plains associated with most of the district’s main rivers. There

• Harnham flood scheme • Water meadows/ Churchfields • Need for flooding/pollution waste issues to be separated out • Localised issues eg drains • Recognised difficult to develop at Salisbury without either going onto floodplains or out into more exposed sites • Soton Rd • Central car park

VARIATION IN FLOOD DEPTH FOR THE RIVER AVON, NADDER, BOURNE AND WYLYE AT SALISBURY

Follow-up work required as result of consultation None at this stage.

THE IDENTIFICATION OF PREFERRED OPTIONS FOR THIS TOPIC AREA Preferred Option from Sustainability Alignment Deliverability*** Other and action**** Stakeholder feedback Appraisal* with national and regional policy** Protect lives, livelihoods and Consistent with SA PPS25, RSS, Yes Ensure that avoidance and mitigation of flood risk properties against flooding PPS1 is included within the strategic objectives of the Core Strategy.

Ensure an overarching principle of avoiding areas of flood risk areas in new development Ensure all development is Consistent with SA PPS25, RSS, Yes Require Flood Risk Assessments in line with consistent with PPS25 and PPS1 PPS25 and follow the sequential / exception other sustainability objectives, approach in site-specific allocations. Promote the and that approvals are use of SUDS. Within allocations, sites will be subjected to the appropriate prioritised which are of lowest risk of themselves appraisal in terms of flood risk being flooded, or of increasing flood risk elsewhere. Development within high risk flood areas can only be allowed under the most exceptional circumstances such as where development is of great strategic importance, there are no more suitable alternative sites, and knock-on impacts can be avoided or mitigated. Recognise future climate Consistent with SA PPS25, RSS, Yes The evidence base will be kept up to date and change impacts on flooding and PPS1 incrementally improved changes in flooding characteristics in the district

*With the Sustainability Appraisal rank from Positive, neutral or negative ** does it accord with strategic policy say yes or no *** Is it a realistic goal? **** Any other influencing factors and given the assessment should it be p[pursued as a preferred option