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Catchment community

Flood protection Somerset levels

A local initiative in Somerset, is seeking government backing for a radical new approach to flooding.

Nina Lovelace reports.

On a spring day, the 28,000ha Somerset Levels and Moors look green, lush and very tranquil. The flat, lowlying expanse stretches as far as the eye can see, criss-crossed with watercourses, and dotted with grazing cattle. In the sun, it is a British landscape at its best.

In autumn 1999, however, the scene was very different. Vast expanses of land were covered up to 3m in floods. Some areas of water extended to over 10km long and 1.5km wide. Dozens of properties were damaged, and delicate habitats swamped.

Now Somerset County Council (SCC) is seeking financial support for a radical new scheme that will ensure such a large scale event is unlikely to happen again.

The Parrett Catchment Project (PCP) is one of five government pilot schemes using catchment-based flood management plans. Flood mitigation is considered for the whole of the levels and moors, rather than on a site by site basis. This ensures that implications of any planned changes on a downstream structure, for example, are realised upstream.

The scheme's main difference, however, is how the PCP has been drawn up. Although originally devised for the region by SCC, it has also involved a plethora of local communities and organisations that have responsibilities, or effects, on the region's water levels.

But as PCP founder member and former councillor Humphrey Temperley explains, in order for it to work properly, sustained financial support is key. As a result, the council is calling for a yearly 7% rise on its current annual £13.9M flood management spend from the Department for Environment, Food and Rural Affairs (DEFRA).

Birth of the PCP dates from autumn 1999, when SCC realised the region's flood management strategy was never going to solve the problems of the Somerset Levels and Moors. 'We had two fairly ordinary floods, but the system was overwhelmed, ' Temperley says.

SCC was keen to work up a new system based on catchments but also knew that a wider view was needed on responsibilities. It was pointless, for example, to continue dredging a river when silting from run-off could be reduced in the first place by planting more trees or adapting farming practices.

Design of new capital works could also benefit from community involvement. For instance, it may not be necessary to dig a new watercourse if a farmer is happy to hand over land for extra storage.

As a result, the beginning of 2000 saw SCC set up a steering group to bring interested parties together, focusing on the most flood prone area, the Parrett catchment. As its name suggests, the catchment feeds into the Parrett and Tone rivers, which then flow into the Bristol Channel.

Floods are made worse when high tides cause the rivers to back up.

The steering group included the usual suspects - the Environment Agency, responsible for the 'main rivers', local councils responsible for smaller watercourses, and 11 separate internal drainage boards on behalf of other smaller ditches or 'rhynes'. But also involved from the start were local MPs, English Nature, the Royal Society for the Protection of Birds and the Country Landowners Association, together with other conservation groups.

A brainstorming exercise was held to source ideas on how different communities and organisations could integrate, and to consider what represented the best capital schemes. By mid2000 DEFRA had also got wind of the scheme, but it was not until February 2001 that it gave official government backing by adopting the PCP as one of five UK integrated catchment management pilots.

The steering group's plans for the next 12 years are outlined in The Parrett catchment water management strategy action plan, published at the beginning of this year. The agency funded report was presented to environment minister Elliott Morley in early April.

Capital works proposals include building a tidal sluice to prevent the rivers backing up, or creating mid and upper catchment storage to slow the rate of run-off and rainfall on to the land. But the report also suggests simpler options such as raising flood banks to control flows, improving the efficiency of pumping stations, increasing dredging programmes and even creating new rivers for extra capacity.

The team is keen to move away from unsustainable options, however. Agency Levels and Moors project officer Andy Baines says that dredging, for example, is high maintenance work. One summer the tides left 4m of silt on the main river beds.

Similarly any new rivers must use gravity rather than pumping to drain into the Bristol Channel.

The report also details how PCP members intend to integrate more efficiently, and how partnerships being created during consultation will be expected to last well into the future. For instance, farming has a key role to play and the local Farming & Wildlife Advisory Group is already contributing advice and expertise.

Better management of arable land upstream is being encouraged, for example, to reduce soil erosion, diffuse pollution and to retain more water on the land. This reduces floods downstream and improves water quality. In addition the PCP is lobbying for such measures to be incorporated in the new government agricultural policies. This could see farmers being paid to use their land for water storage.

The PCP and the Agency are also planning a series of seminars to remind developers of their responsibilities under PPG25, regarding development in floodplains. This will include the promotion of sustainable urban drainage systems to slow the rate of run-off.

Advancing to pre-feasibility stage, the Agency is currently investigating how the delicate environment of the catchment may be affected by the various capital works schemes, and modelling how the rivers would react to construction.

'We've got the bulk of the information to feed into the modelling process, ' says Baines, although there are gaps in the Agency's knowledge of the topography and flood history.

Hands-on level surveys will be needed on some large close to flat expanses, he says.

Once modelling and environmental surveys have revealed the most workable plans, there will be another round of consultation before more detailed scheme by scheme feasibilities.

These will also include all important cost benefit calculations to attract extra DEFRA grant aid for key works. The tidal sluice, for example, is expected to cost between £15M and £18M.

In the meantime the Agency has been carrying out emergency work to beef up flood protection until the catchment scheme is in place. This has included raising embankments, strengthening banks, improving reliability of pumps and sluices and a new programme of dredging.

INFOPLUS nceplus.co.uk/magazine/ flooding

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