Stocks Reservoir lies in the Forest of Bowland at an altitude of 180 m. It is approx 3 km long and varies in width from 200m to 1,250m, with an island in the broadest part. In view of the distances involved, a telescope is recommended. The River Hodder runs through from north to south, and the other major feeder is Bottoms Beck which runs from the north east and in under the causeway.The Bowland Fells lie to the north and west and Gisburn Forest to the north east.
Access:
The reservoir is best approached via the unclassified road which runs from the B6478 between Tosside and Slaidburn. Turn off the B6478 by the telephone kiosk at Stephen Moor Crossroads, SD748543.
There is no public transport; there is a pay and display car park at the bottom of School Lane SD732565 – tickets are interchangeable between here, Gisburn Forest Hub and Cocklet Hill – two hides just off the permissive footpath (which leaves the car park running north west), at SD730567 and at SD728579 respectively and a picnic site in the old vicarage garden between the two at SD731566. The nearest toilets are at Gisburn Forest Hub, Stephen Park where there is also a cafe. The reservoir is best viewed from the hides, picnic site, causeway at SD737561, or from many points on the permissive path which to runs right round the reservoir, but well away from the banks to which access is restricted.
A log book is kept in the second of the two hides. Visitors entering records are asked to sign their name and also to leave a contact address or telephone number if reporting anything unusual.
Fly fishing is allowed from bank and boats in the southern two thirds at certain times of the year, but not from the island nor from the shore at the north end or Hodder Inlet (which the hides overlook).
Access to the fishery is off the Bentham road which runs north from Slaidburn. Birdwatchers are advised to avoid this approach.
Birds:
Little and Great Crested Grebes both occur but falling water levels usually prevent breeding. Great Cormorants haul out on the island at all times of the year and roost in trees at the Hodder inlet. Raptors recorded in recent years include Eurasian Marsh Harrier (rare on passage), Hen Harrier, Northern Goshawk, Eurasian Sparrowhawk, Common Buzzard, Osprey (annual on Spring passage, more rarely in Autumn), Common Kestrel, Merlin and Peregrine Falcon. Short-eared may be seen on the surrounding moorland while the forest holds Tawny and probably Long-eared Owls. Raven are seen regularly.
There is a large winter gull roost which includes many Common as well as larger Gulls. Black, Common and Arctic Terns are seen on passage.
Stocks is best known for wildfowl and waders. Species marked* are known to breed. Wildfowl recorded in recent years include Whooper Swan, Pink-footed Goose, Greylag Goose, Canada Goose*, Barnacle Goose, Shelduck, Wigeon, Gadwall, Teal*, Mallard*, Pintail, Garganey, Shoveller, Pochard, Ring-necked Duck, Tufted Duck, Scaup, Common Scoter, Goldeneye, Red-breasted Merganser* and Goosander.*
Some waders breed* around the reservoir while others are seen only on passage. Species recorded in recent years include Eurasian Oystercatcher*, Little Ringed Plover*, Ringed Plover, European Golden Plover (on surrounding fells), Grey Plover, Lapwing, Knot, Sanderling, Little Stint, Temmincks Stint, Pectoral Sandpiper, Curlew Sandpiper, Dunlin, Ruff, Snipe, Jack Snipe, Common Snipe, Woodcock* (in forest), Black-tailed Godwit, Bar-tailed Godwit, Whimbrel, Curlew*, Redshank*, Greenshank, Green Sandpiper, Common Sandpiper* and Turnstone.
At Spring passage as many as 11 species of wader have been present at the same time. The number of passage waders is affected by the amount of draw-down and hence exposed mud.When water levels are high it is worth checking the flood pool on nearby Champion Moor at SD749523.