Greywell Moors Nature Reserve, Hampshire

Greywell Moors, a nature reserve and part of the larger Greywell Fen Site of Special Scientific Interest, is an area of wet grassland, wet woodland and calcareous fen, alongside the Whitewater River, near Odiham in northeast Hampshire. The river and its tributaries flow over chalk rocks from the Seaford Formation; such chalk streams are very rare, with only around 200 in the world, the majority in this area of England. The water is exceptionally clear and pure, cleansed by natural filtration, and the white bedrock contrasts pleasingly with the rich green of underwater plants, including starwort and water crowfoot.

The 32 acre reserve is noted for a great variety of mosses, liverworts, rushes and sedges, and has a few showy plant species including marsh helleborine, marsh lousewort, pepper saxifrage and southern marsh orchid. The fen, on the east side of the river, contains a number of clear pools fed by springs, which also harbour a selection of aquatic plants. Insect and bird life is abundant, and grass snakes are frequently spotted.

The Reserve

The main section of Greywell Moors Nature Reserve extends 0.7 miles along the river, and may be explored by two paths along its perimeter, allowing a loop walk of about 1.6 miles. Lesser paths access some areas but much is rather inaccessible due to the wet or water-logged ground. The recommended parking place is at the north end of the reserve, along Deptford Lane, between Odiham and Greywell, on verges at the entrance to a pumping station. The eastern path starts just down the street, running mostly over fields and through scattered groups of trees. After 800 feet a path forks off at right angles, crosses the river on a footbridge and links with the west section of the loop. At another junction, just beyond the far end of the reserve, the return path heads north, right beside the Whitewater River, along the edge of the fen and on to a old water mill, now a private house. The trail continues through a patch of woodland and the grounds of the local church, St Mary's, then finally crosses a large field back to Deptford Lane. A smaller, grassland section of the reserve lies north of the lane, open by permit only.