THEY say what goes around comes around and so there's rich irony in the fact that after decades of trying to keep our rivers within their banks, it's now been decided it wouldn't hurt if some water escaped.

The straitjacket approach, designed to prevent the floods that inconvenience the human race occasionally, is having a disastrous effect on wildlife.

Because the land alongside the rivers no longer gets its seasonal soaking, it is drying up.

This draining of the wetlands, as the effect is called, has already contributed to the decline of the otter population, helped cause a severe drop in the numbers of white clawed crayfish and very nearly done for the poor old water vole.

It's a case of homo sapiens sticking his oar in without really appreciating the consequences.

Fortunately, riding to the rescue, comes not a man on a white horse or even atop a leaping salmon, but a man in a van with Worcestershire Nature Trust emblazoned on the side.

Andy Graham is the Trust's water for wildlife officer and, thanks to financial support from Severn Trent Water and Fuji Hunt the photographic people, he is on a mission to restore our traditional landscapes, particularly the wetland areas.

As part of this project, the Trust has already bought two tracts of land for wetland restoration.

One is at Longdon Marsh, south of Upton-upon-Severn, and the other is by the River Avon near Pershore, which will be known as the Gwen Finch Wetland Reserve, after a lady who left money to help otters. Previously agricultural land with little wildlife value, the latter site is now home to a multitude of wading birds, insects and other water-living creatures.

"The drying out of the wetlands has really become severe in recent decades," said Andy.

"The policy was to 'tidy up' riverbanks and make them more secure against flooding, but this had a knock-on effect on the wildlife that relied on the wetland areas for its habitat.

"Of course, it wasn't the only factor that contributed to the decline of the otter, but it was significant.

"Likewise with the white clawed crayfish, which is our only freshwater lobster. This also suffered badly from a crayfish plague, brought into this country from Sweden, and now it can be found in only two areas in Worcestershire - in the Wyre Forest and at two sites near Malvern.

"The crayfish only come out at night so you need a torch to see them. They are pretty near the bottom of the food chain, because they eat mainly rotting leaf debris. Although it doesn't help that they also eat each other."

However, the good news on the river front is that otters are making a comeback. A fourth national survey of the creatures showed its numbers have made great strides on the River Severn over the last 10 years. Positive sites are now up from 105 to 127.

But the mystery remains why the population appears to be growing on the upper Severn, but not on the river's lower reaches, especially below Worcester.

"The Severn below Worcester is now quite artificial," said Andy.

"It has been heavily modified for recreational boat traffic and the type of river management needed for navigation has resulted in the almost complete absence of the sort of habitat otters prefer.

"Nevertheless, we would still have expected to see some signs of them, especially as there appear to be adequate fish stocks.

"If anglers were coming back and telling us there were few fish, it might explain the situation. But they are not."

A project is currently being organised to try to pinpoint just why otters don't want to travel south of Worcester.

As for the water vole, the little creature has disappeared from almost 90 per cent of the sites it occupied in Britain 60 years ago. This is largely due to the loss of its riverbank homes and being preyed upon by mink.

It is also sometimes mistaken for a brown rat and poisoned. Pointing out the difference between the two species to pest controllers and the general public is high on the Nature Trust's list.

Of course, reviving the vole's natural landscape along the riverbanks would be one sure way of getting the creatures back to where they once belonged.

"If you approach landowners about re-creating areas of wetland alongside rivers, their big fear is that it will lead to an increase in flooding.

"But we have found this isn't so. With careful management, you can achieve both aims."

Let's hope so.