With its source at the southern end of The Eden Valley high on the fells above
Mallerstang, the River Eden flows north to the Solway Firth.

The whole of the River Eden and its tributaries is  designated a European Special
Area of Conservation and a SSSI, reflecting the diversity of wildlife and flora found by and in the river and its many tributaries.  The whole range of wild trout habitats are found in this special river system, from fast flowing, thin upland waters through riffles and pockets on the higher feeder becks from the slopes of the Pennines, Howgills and Lakeland fells, and down into the broad Eden valley. As the waters slow they retain a character which is ideal for the strong populations of wild trout and grayling, and the invertebrates on which they feed.
The Eden Rivers Trust, along with other conservation-orientated groups, including Natural England and Cumbria Wildlife Trust, are very active throughout the Eden system, repairing the agricultural damage that has been done over (mostly) the last 20 years, with the aim of restoring the river to the pristine set of habitats for which it is justifiably famous.

There remain very many stretches of main river and tributary which are outstanding in the European context as healthy habitats for wild trout and the many temperate zone plant and animal species for which the area has historically been so rich.  We are very fortunate that the Appleby waters hold a lot of such habitat.

The river collects from numerous substrates over an enormous water catchment, on the English scale, dominated by sandstone and limestone.  The resulting slightly alkaline pH, among the variety of river habitats, results in a diverse invertebrate populations which are currently probably the most healthy in the agriculturally-damaged English landscape.  In May and June, anglers can count upwards of eight different ephemerid species hatching simultaneously, along with numerous caddis and midge species.  Gammarus shrimps are a constant food source for the trout and grayling, throughout the year.