Hidden beneath the rich green farmland of the rivers Ure and Swale floodplains lie millions of tons of gravel. Products of a dynamic geological system that has seen the course of the rivers shift a mile or more since the last ice age, man, looking for building materials, has quarried them for decades. The resulting holes in the ground, often full of water as the "gravelling" reaches below the water table, lie starkly against the backcloth of ordered green arable fields and shelter belts of trees and close cropped, ruler-straight hedgerows.
In the past, they would probably have been backfilled, perhaps with household waste, and returned to agricultural use. In today's world, many are earmarked for water sports, an income-generating activity, and some even for wildlife conservation.
Fortunately, the natural world needs little encouragement to recolonise these sites, and there is strong support for a strategy of allowing nature to regenerate at its own pace. This contrasts with the instant habitat approach favoured elsewhere. At Nosterfield, a site purchased from Tarmac Ltd by the Lower Ure Conservation Trust, I watch lapwing cartwheeling through the sky, like manic stunt kites, while a redshank potters sedately along the water's edge. Simon Warwick, chair of the trust and a passionate enthusiast for establishing wetland habitat along the Ure and Swale valleys, tells me that seven pairs of shoveller have nested this year and that the nature reserve is now established as the most important site in the county for wintering and migrating wading birds.
We moved on to a much smaller site a few miles away, where gravel extraction has taken place for generations on a scale little more intensive than a couple of men with shovels and wheelbarrows. Here we were greeted by banks of cowslips and, on the disturbed, open, sandy soils, common stork's-bill, doves-foot cranesbill and carpets of deep blue speedwell. In the trees which have clothed the banks of spoil left behind from the workings, turtledoves droning their distinctive burring call.
Simon has a vision of a chain of naturally regenerated wetland sites along the river valleys. Given the extent of current and planned gravel workings, he will probably realise his dream.
