Holdfast Training Services Trial Blog

Having left behind the big smoke in favour of a more sedate life back in Devon, I’ve joined Atkins consultancy, and am based in Exeter. Part of a global brand, the Exeter office takes the lead on local projects which offer a wide variety in scope, and has offered me to the chance to get stuck in from the off. So far, I have been involved in four main projects, each at different stages of the design process.

They are as follows:

1.Slope stability analysis on an earthfill reservoir embankment in Bruton, Somerset.

2.Production of a scoping request ahead of a planning application on Linhay Hill Quarry, extension works, Ashburton

3.Project management of a planning application for an organic foodwaste recycling plant, Avonmouth, Bristol

4.Drainage design on new school within a development scheme at Mudford, Somerset. Whilst you’re still reeling from the sheer scale and profile of these projects (Burj Khalifa 2 is next month apparently…), I will give you a snapshot of some of the planning legislation and guidance that I have become familiar with on the Avonmouth job.

Background. Wessex Water Enterprises’ business unit, GENeco, leveraged spare capacity at the Avonmouth sewage treatment works to build an organic food waste plant in 2010/11. This ‘stomach in a shed’ takes approximately 30,000 tonnes of food waste from across the wider Bristol region, and processes it into methane and digestate fertiliser. These by products are recycled in to a number of uses including fertiliser for the agricultural industry, and even to power the cities buses. Check out the link to a CBBC rundown on the plant, which is at about the correct level for my childish mind…

http://www.geneco.uk.com/Food-waste-recycling/Default.aspx

Given the success of Phase 1 of this development, GENeco wishes to submit a new planning application to deliver Phase 2 of the works. The Avonmouth development will constitute an expansion of existing works delivered in Phase 1. The proposed new development will add an additional 30,000 tonnes per year of capacity to the plant. GENeco have approached Atkins to support a planning application for an expansion of the plant.

Client Specification. Wessex Water support their own small engineering services team, and have decided to deliver some of the aspects of the planning application themselves. Whilst this has led to a slightly incoherent approach, much of the planning application from Phase 1 is likely to remain extant which should serve to de-risk this process. The scope of Atkins involvement has been reduced to the following sections of the report.

(1).         Scheme Drawings

(2).         Transport Statement, to include travel plan

(3).         Landscape and Visual Impact Assessment

(4).         Site specific flood risk assessment

(5).         Odour assessment

(6).         Air quality assessment

Contract. Atkins have utilised a standard form of consultancy agreement; specifically the Consultancy Services Contract. This enables the provision of consultancy services and deliverables, in which the deliverables are clearly defined. Each deliverable is priced in isolation; a clear explanation of the basis of the costings is given, including named participants and their hourly rate. Either party may request a change to the scope or execution of the services, but importantly the consultant has no obligation to perform the variation until all variations in fees and services have been agreed. In this instance, when the scope is unclear, this provides a risk share for both parties, as each development in scope can be judged on its individual merits and agreed upon in isolation. However, the key managerial issues in this example are at the local level. The scope straddles a number of functional areas within the broader Atkins organisation, and so implied in the deliverables is a project management function. However, in order to remain competitive at tender, project management fees were ‘scoped out’ and currently those costs are lost in each of the departmental fee proposals.

My role. Perhaps predictably, I have taken on the role of ‘free at point of sale’ project manager. Initially I prepared and issued Inter Unit Work Orders (a formal arrangement between departments that agrees requirement, program and costs) to each department and negotiated their program lengths and costs. This was captured in an offer letter, which was sent to the client for agreement. The tender was then awarded. I have issued a tasking order which provides an overview and initial proposal layout, with guidance on program and resourcing. I included an RFI matrix, which has enabled me to liaise with the client and key stakeholders, such as Bristol City Council, to manage the information flow between all parties. Weirdly, this has made me the toast of the town!   I have also been tasked with the production of the Flood Risk Assessment, which I submitted this week aswell as Odour and Noise Assessment.

Legislation All the planning policy guidance is contained within the National Planning Policy Framework (2012). Aswell as being a ripping good yarn, it sets out all the governments planning policy in one easy to read document. This is considered a huge improvement to the system before 2012. In the context of flooding, the broad aim of the National Planning Policy Framework, March 2012, is to reduce the number of people and properties within the natural and built environment at risk of flooding. To achieve this aim, planning authorities are required to ensure that flood risk is properly assessed during the initial planning stages of any development. The responsibility for flood risk assessment lies with the developer and they must demonstrate the following:

• whether the proposed development is likely to be affected by flooding;
• whether the proposed development will increase flood risk to adjacent properties; and
• that the measures proposed to deal with any flood risk are sustainable.

Sequential Test and Vulnerability Classification. In order to establish these aims, the ‘Sequential Test’ is used to steer new development to areas at the lowest probability of flooding, with the starting point for the sequential approach being the flood zones detailed in the Technical Guidance to the National Planning Policy Framework. Development should be directed to Flood Zone 1 wherever possible, and then sequentially to Flood Zones 2 and 3, and to the areas of least flood risk within Flood Zones 2 and 3. Where there are no reasonably available sites in Flood Zone 1, local planning authorities determining planning applications for development have to take into account the flood risk vulnerability of land uses, again outlined in the Technical Guidance to the National Planning Policy Framework, Vulnerability Classification.

Risk Categorisation. Flood risk includes the statistical probability of an event occurring and the scale of the potential consequences, and the risk is estimated from historical data and expressed in terms of the expected frequency (or ‘return period’) of a flood of a given magnitude.  For example the 10-year, 50-year and the 100-year floods have a 10%, 2% and 1% chance respectively of occurring in any one year, and those values are termed the Annual Exceedance Probability, AEP. However over a longer period the probability of flooding is considerably greater, hence for example, for the 100-year return period:

• There is a 1% chance of a 100-year event occurring or being exceeded in any year.
• A 26% chance of it occurring or being exceeded in a 30-year period.
• A 51% chance of it occurring or being exceeded in a 70-year period

The Technical Guidance to the National Planning Policy Framework, March 2012 defines flood zones in relation to the probability of river and sea flooding, ignoring the presence of defences, and details the appropriate land uses, Flood Risk Assessment (FRA) requirements and policy aims for each zone. The Environment Agency provides Flood Zone maps available via its website which are used as the starting point for all FRAs. From inspection of those maps, the central section of the Avonmouth site, i.e. the existing reception centre near the drainage ditch (the ‘rhine’ network) lies within the Environment Agency’s indicative flood zone 3, defined as high probability of flooding, by the Agency. The Technical Guidance to the National Planning Policy Framework, March 2012, also requires the vulnerability of the development or land use to be taken into account as the consequences of flooding may not be acceptable for particular types of development, and it defines Flood Risk Vulnerability Classification for the proposed use of development sites. With reference to that table, the proposed development land use, namely waste treatment facility, is classified as ‘less vulnerable’.

Town and Country Planning (Flooding) (England) Direction (2007) Due to some inappropriate developments being granted in flood risk areas against advice of the Environment Agency, the Secretary of State under the County Planning (General Development Procedure) Order 1995 (“the Order”) made the Town and Country Planning (Flooding) (England) Direction 2007 (the Direction) which came into force on 1st January 2007, to provide a safeguard against such cases The National Planning Policy Frameworks states the requirement for a Regional Flood Risk Appraisal to provide a broad overview of the flood risk issues across the region; in this instance the South West of England. It seeks to highlight key areas where more detailed study is required at a sub- regional level. I consulted the South West Regional Flood Risk Appraisal (RFRA), February 2007 with regard to the proposed development, and Avonmouth is considered as an area of sub regional flood risk. The area of Avonmouth, Severnside and Royal Portbury Docks are characterised by a ‘substantial coastal flood risk’, where property is at risk from tidal and fluvial flooding. Additionally, surface water drainage can be subject to ‘tidal locking’ at high tide. This risk is mitigated by tidal flood defences which are installed between Avonmouth and the Severn Beach. These offer protection up to a 1 in 100 year event. That said, the effect of climate change and the rise in sea levels is a major concern in the Avonmouth region. It is estimated that severe tidal flooding events will be six times more likely to occur by 2060 (i.e a 1 in 200 event now, will become a 1 in 33 year event).

Planning Policy Statement 25 (PPS25) Development and Flood Risk (Communities and Local Government) issues detailed guidance on the assessment and management of flood risk. Within this it directs local authorities to produce a Strategic Flood Risk Assessment for their area of administration. A Level 1 initial assessment is carried out for all the administrative area by the Local Authority to understand the flood hazard. Where this study indicates an area of flood risk, a second, and more detailed study is commissioned to collect further information of the distribution of the flood hazard. The Level 1 SFRA in this case, indicated Avonmouth as a key area requiring further detailed assessment of fluvial and tidal flood risk. The Level 2 SFRA states that the vast majority of the Avonmouth area is considered as at a high probability of flooding (Flood Zone 3a – 1% AEP river flooding or 0.5% coastal flooding). If there were no tidal defences, extensive flooding could be expected. It is also clear that the Avonmouth/Severnside area is very susceptible to tidal/surge flooding from overtopping the defences. In this instance, the sequential test demonstrates that there are no alternate reasonably available sites in areas with lower probability flooding. As stated, the development is proposed as an extension to the existing anaerobic digestion plant, and therefore needs to be located adjacent to the existing works. As the Bristol STW is located entirely in the designated flood zone 3a, there are no alternate lower probability (zones 1 and 2) which would be preferential for the proposals. The ‘Exception Test’ should therefore be applied. In this test, it can be shown that:

1. The development provides wider sustainability benefits to the community that outweigh flood risk
2. It is proposed on land previously developed.
3. A site specific flood risk assessment will be included to demonstrate that the development will be safe, without increasing flood risk elsewhere

Next steps… My flood risk assessment demonstrated a medium to high risk from a tidal event, which is increasing with climate change. Fluvial flood risk is medium. The Avonmouth flood defences in the immediate area mitigate this risk somewhat, but The Environment Agency don’t own the full length, and therefore the maintenance scheme is hit and miss at best. I therefore recommended that the residual risk remains at medium to high. I approached the client informally ahead of the publication of the risk assessment to recommend further consideration to mitigation measures. I was told in no uncertain terms that there was no aspiration for this, and certainly no budget at this stage, and given the ‘less vulnerable’ status of the industrial unit didn’t justify further expenditure. Ill still be taking my wellies on my site visit on Wednesday….