Current Stuff
Old Stuff












Carved-up thinking

Practical planning advice AJ May 2001

by Brian Waters

Just when you thought that the flood of obstacles to new development (contaminated land, environmental impact, sequential testing et al) was abating, along comes another one. This is the risk-based sequential test which directs developers and authorities towards sites with a low risk of flooding. And it is backed up by making flood risk a material consideration to be given appropriate weight in determining planning applications as well as in preparing development plans. A draft PPG 25 Development and Flood Risk was published a year ago. In March the government revised the draft1 to take account of last autumnÕs severe floods, consultation responses and the report of the House of Commons committee on the development of or affecting the flood plain which was published last December. In announcing the revised draft minister Nick Raynsford said ÒThe revision toughens and sharpens the precautionary risk-based focus of the original draft.Ó

Only four weeks has been allowed for further consultation and he said Òthe reasons for the shorter consultation period are that this is an urgent matter on which new guidance is required without delayÓ. He went on to explain that the government is committed to reviewing the impact of the guidance on developments in three yearsÕ time with particular reference to further information about climate change. The minister is also considering issuing a Flood Direction, which would ensure that the views of the Environment Agency on a flood risk are properly considered. However, this must wait for the outcome of the House of Lords decision on the compatibility of the Human Rights Act and the Secretary of StateÕs planning powers. He concluded ÒThe experience of the last few months has demonstrated the cost to all parties of development being located in vulnerable areas. Flood risk has to be taken more seriously, particularly since climate change is unlikely to increase the scale and frequency of flooding in the future. A proper consideration of flood risk requires stronger and tougher guidance on which we are now consulting.

As part of the consultation, we will be seeking views on the regulatory impact and the costs and benefits of implementing this guidance.Ó Not only will PPG 25 oblige architects to advise clients of their new responsibilities and the possible vulnerability of their land to flooding and of their planning applications to refusals. They will also have to be alert to the effects that this guidance is going have on particular sites when development plans are reviewed including the effect on housing land allocations. This will be easier said than at done for several reasons. There are two important areas of uncertainty and a considerable probability of policy conflict for many potential development sites. The uncertainty arises from a lack of scientific conclusion of the effect and seriousness of climate change, for which reason the whole matter is to be reviewed again in three yearsÕ time. More practically the indicative flood plain maps which have been produced for the whole country (and which are available on the Internet) have been received very sceptically by some, notably Sir Peter Hall, as being far too crude. This has been admitted by the Environment Agency who are now giving priority to the provision of more accurate maps.

A recent EA presentation to the London Planning and Development Forum2 showed the importance of the work that the agency is doing and demonstrated the need for a great deal more to be done. The areas of conflict will be demonstrated in attempts to carry out the risk-based sequential tests required by PPG 25 which intends to direct new development towards sites with a lower rather than a higher flood risk and to avoid any such risk unless the need is demonstrably exceptional. The priority for new development to be targeted at Ôbrown fieldÕ rather than Ôgreen fieldÕ sites is likely to throw up conflicts both in plan-making and in developersÕ intentions. Examples both large and small are likely to emerge. The Thames Gateway falls into the Mega category: many strands of development policy seek to develop large areas here which are likely to fall well within the 100-year flood zones of the Thames estuary (the Thames barrier is designed to meet the criterion only until 2030) and the consequences of such conflicts will add complexity and the need for compromise as plans evolve and proposals are evaluated. Interestingly, the government has no statutory duty to protect land or property from flooding, but it is responsible for producing national strategic guidance and flood defence measures.

The Environment Agency can only intervene with limited discretionary power to target defence measures at existing development. The primary responsibility for safeguarding the land and other property rests with the owner, extending to insuring the adequate drainage of land to prevent impact on neighbouring land. PPG25 stresses the importance of the precautionary approach, to avoid flood risk entirely wherever possible and to manage it elsewhere. The need for development has to be balanced against the risk, for the new development and for other areas. While the guidance does not advocate a complete ban on building in flood risk areas, it recommends giving consideration to sustainable development and the wider impact on the environment. There is a greater emphasis on developers taking responsibility for providing adequate information on flood risk in support of any planning application.

Developers will have to demonstrate an awareness of flood risk, any consequential constraints on the proposed development and alternative means of mitigation. Where such development is unavoidable, developers will be expected to contribute to the cost of flood defence works. PPG 25 suggests the conditions may be attached to permissions to prevent the commencement of development until flood alleviation works have been completed. Architects will have to learn more about mitigation methods including how to hold water run-off from new surfaces and roofs, permeable and retentive car-parking surfaces, balancing ponds and all the rest. Expect more water features to crop up in landscaping schemes. But planning as ever is a balancing act and PPG 25 introduces yet another factor into the balance.

Flood risk will now have to be weighed against meeting housebuilding targets, and brown field land objectives, and the urban regeneration policies of the urban White Paper. And for many sites, getting planning permission will be even harder.

References See the draft PPG 25 at www.planning.detr.gov/consult/revppg25/index. htm Flood water, flood risk and groundwater in April's Planning in London from 020 78349471 Seek full minutes of this discussion at www.planninginlondon.com > L P and D F.


The key provisions in new draft PPG25 are as follows:

The primary objective is that new development must be safe Ð to reduce the risk to people as well as the developed and natural environment. Flood risk a material consideration to be given appropriate weight in determining planning applications, preparing local and structure plans. Emphasis and guidance on sustainable drainage systems to reduce the volume and rate of surface run-off from development sites. Improvement of information available to the community about risks of locating human activity in areas susceptible to flooding. Developers to contribute to flood defence works where development in a flood risk area is unavoidable. Imposition of conditions preventing implementation of development until flood alleviation works are completed Protection and maintenance of a civil emergency infrastructure which is accessible at all times (e.g. hospitals, fire stations, police stations and emergency vehicle depots). The Environment Agency has to have a lead role in providing strategic advice. Further studies are to be undertaken within three years, to ensure continued monitoring, research, surveillance and study of the environment.

Brian Waters is principal of the Boisot Waters Cohen Partnership. Tel 020 7828 6555 or e-mail brian@bwcp.co.uk