MOST years in late March, half a million trout fishers are tossing restless abed. The winter has dragged like an anchor chain and the new season is dawning. Asleep or awake, trout — feverishly rising trout, improbably large trout, artfully deceived and skilfully landed trout — constantly drift into mind.

Alas, anticipation is one thing, actuality another. For many, 2005 is not going to be “most years”. While the early prospects look good everywhere, the longer-term outlook on the most famous, most intensely fished and expensive rivers of all, the chalk streams of the East and South, looks grim.

What in places has been the driest winter for 130 years, and the unusual way in which these rare rivers work, has all but ensured it. Most rivers rise quickly when rain runs into them from the surrounding land. The streams welling from the broad band of chalk that runs from Lincolnshire south and then westwards through Dorset can take months to respond. In this vast area, rain does not run off the chalk ground but soaks into it. Water can take months to reach the aquifers deep underground that keep the rivers topped up.

The result this parched year is that the underground aquifers are perilously low when they should be brimming and any rain falling now will not replenish them in time.

So, barring miracles, the die is cast. Even on the biggest and most robust streams of all — rivers such as the Itchen and Test in Hampshire, the Kennet in Berkshire and the Avon in Wiltshire, famous waters that attract anglers from all over the world to fish them at up to £300 a day — the prospect is for steadily falling levels, silting gravels, a dearth of water plants, a further decline in aquatic flylife and dour fish.

April, May and June will produce some of the surface activity for which these rivers are famous and dry flies and nymphs will account for their quota. But after that, with the fish hugging the bottom in the deeps and the shade, rises will be a rarity. Weighted nymphs cast to sighted fish will bring the odd response during the day. Beyond that, hope will be pinned on last light and a brief evening rise.

Reports from Scotland, Wales and northern and western England indicate flows mostly around normal and the outlook there is more promising. Teams of traditional wet flies and spiders will take early fish, especially if a weighted nymph is used on the end on cold days to make the flies swim deeper. From mid-April through June, small upwinged flies will be in evidence and dry flies will produce. What happens after that will depend mostly on rainfall, but the North Country master, Oliver Edwards, has a useful tip.

Edwards has noted that bankside sycamores harbour vast populations of aphids, which fall into the water by the million. Trout know it well and line up downstream of these trees and gorge, he says, revealing their presence only by near-imperceptible sips. Imitations as tiny as size 26 flies — so tiny that ten could sit on a fingernail — can, he says, conjure bags from probable blanks for those capable of handling them and the gossamer leaders that are necessary.

Most of the big, trout-stocked reservoirs have water levels close to normal and plenty of fish close in to the banks. Some remarkable fishing has been logged. Anglers at Ravensthorpe, in Northamptonshire, have been averaging an astonishing six fish apiece and at Foremark, in Derbyshire, limit bags have already been taken on dry flies. Grafham, near Huntingdon, and Chew, near Bristol, have produced big bags to buzzer patterns fished on long leaders from floating lines.

These marginal fish will spread out before long and in summer they will take to the deeps. Then, large lures and fast-sinking lines will take fish during the day for those willing to use them, but, as on rivers, it will be evenings that will provide the most consistent sport.

So, as in most years for most anglers, the new season is an unwritten page. In the parched chalk belt, however, flyfishers should make the most of the sport they are enjoying now. It is with those feverishly rising trout, improbably large trout, artfully deceived and skilfully landed trout — which, sadly, are all in the mind.

TOP TROUT TIPS

If barbless hooks are used, fish can be released without them leaving the water — important in high-summer, low-oxygen conditions.