Trail of the unexpected

"Oh I wondered what they were building down there," said a friend of mine, when I mentioned that I was planning to visit the Jubilee River. "Do you remember they diverted all the traffic on that part of the M4, but no one seemed to know what was going on?" It wasn't just the M4 that had to be diverted in order to construct Britain's newest waterway: gas, electricity, sewers and telephone cables were all re-routed, and three new bridges had to be built to carry the railway lines over the water. Now, after five years of work, and many more of planning, the Jubilee River has finally been completed.

"Oh I wondered what they were building down there," said a friend of mine, when I mentioned that I was planning to visit the Jubilee River. "Do you remember they diverted all the traffic on that part of the M4, but no one seemed to know what was going on?" It wasn't just the M4 that had to be diverted in order to construct Britain's newest waterway: gas, electricity, sewers and telephone cables were all re-routed, and three new bridges had to be built to carry the railway lines over the water. Now, after five years of work, and many more of planning, the Jubilee River has finally been completed.

This man-made channel cut through the Berkshire countryside is a flood alleviation scheme, designed to protect the inhabitants of Maidenhead, Windsor and Eton from the threat of flood damage, by diverting water from the Thames when the level gets dangerously high. The Jubilee River forks away from the Thames at Boulter's Weir, north of Maidenhead, and flows east for seven miles until it rejoins the main river at Black Potts viaduct, close to the point where eastbound trains from Windsor cross the river on their way to London.

For something that has just been built, the Jubilee River looks remarkably well-established. This is a tribute to groups such as English Nature and the RSPB, which have worked with the Environment Agency to turn the area into a habitat attractive to wildlife. Even though the river is new, the range of birdlife is already impressive, and even the inexperienced eye might recognise the cormorants lined up on the yellow barrages that protect the weirs, or the green woodpecker flying low over the shrubs along the water's edge. The aim of the conservationists is to re-establish some of the plant and animal life that has been lost in the Thames valley as a result of urban development and the ever-increasing traffic on the Thames.

Artificial islands have been created at various points in the Jubilee River to allow birds to nest without risk of being disturbed by passing walkers or their dogs, and families of swans can be glimpsed through the vegetation. The water nearest to the banks is shallow and marshy, encouraging aquatic plants, fish and wading birds, while rarer species are expected to settle in the specially created reed beds; many of these are surrounded by deep pools, which will provide shelter for herons and kingfishers. Since some of this will be out of sight – and out of reach – of those who come to enjoy the river, a special wetland area has been established at Dorney, about halfway along the path. This has been designed with hides and boardwalks, to allow for closer inspection of the wildlife.

It is the river banks themselves that give away the newness of the whole scheme. A quarter of a million trees and shrubs have been planted, but for now most are only beginning to peep above the netting that protects their trunks. Drifts of water plants and wild flowers have also been put in, which, when they are fully established, will provide a lush border. It will take time for this to happen, and for the moment patches of bare earth still show through; but part of the pleasure for early visitors will be to return in years to come and see how the habitat has matured.

Although its main function is as a flood barrier, the Jubilee River has also been designed to be an attractive recreational facility, despite the noise, at the eastern end, from the planes flying in and out of Heathrow. The closeness of the M4, particularly around Slough, is also a disadvantage, however, the noise should soon be deadened as the vegetation provides a natural barrier. A path along the south side of the river has been gravelled, to provide access for walkers, cyclists and wheelchair users; and there are bridleways along part of the river as well. Newly installed footbridges connect with existing paths, or provide access to picnic areas.

All that is needed to complete the ingredients for a day out is more benches along the riverbank, for those who want to sit and enjoy the surroundings; and perhaps some toilets, located in the four car parks that have been built along the route.

The Jubilee River has already been operating as a flood defence for several months, but it will have its official opening on Thursday next week. The water levels in the Thames are regulated by a series of weirs built into the new river. These can be opened to divert water away from the Thames as its level rises.

The last time Maidenhead was seriously affected by flooding was in 1947, when more than 2,000 homes were affected. The same thing could happen again at any time, although this time the damage would be even more devastating: the number of homes in the area has more than doubled in the last half-century. Now, although it is impossible to eliminate the risk of flooding completely, protection has been greatly improved; and the area has a new environmental attraction to show off.

For information on the Jubilee River, its opening ceremony, or the special open days which will be held on 11 and 13 July, contact the Environment Agency on 0845 933 3111 or www.environment-agency.gov.uk.