There are two reservoirs located in Onchan - The Clypse and The Kerrowdhoo.
The Clypse Reservoir is the upper of two reservoirs in the Onchan area and was built in 1876.
The Kerrowdhoo Reservoir is the lower of the two reservoirs and was built in 1893 and is larger than the Clypse Reservoir.
Both reservoirs take their water from the Groudle River and covers a catchment area of 562 acres.
There are three marked nature trails; The Reservoir Trail, The Groudle River Trial and the Upland Trail. Each have interesting flora and fauna and there are ruined remains of former farms. For further information, please see Nature Trails.
Fly fishing only is the rule. Brown and rainbow trout of two pounds and more are reasonably common, while much bigger fish can be caught by a skilled angler.
Both reservoirs have areas where the fish prefer to collect. The top narrow section of Kerrowdhoo reservoir is known as the "neck" and the shallow southern section near the embankment is known as the "flats"; each can be productive in fishing terms depending on the time of year and the time of day. Vegetation on the margins of the reservoirs provides attractive shade and overhanging cover for insect and fish alike.
On a still calm summer's evening when the flies are hatching and Clypse and Kerrowdhoo waters are tranquil, trout can be seen rising to the surface. As dusk nears, the last few minutes of the rise are normally the most furious and anglers will often be found arriving for the last few hours of sport.
There is plenty of parking, though it is shared between the Clypse and the Kerrowdhoo Reservoirs.
All the trails can be accessed via the Mountain Road (A18) as far as the base of the Hillberry Straight then take the Ballacottier Road and Clypse Moar Road to the Clypse-e-Creer car park.
The Uplands Trail can be reached by continuing up the Mountain Road then turning into the Creg-ny-Baa Back Road to use either HoneyHill Road or Conrhenny Road footpaths. Please park carefully on the Creg-ny-Baa Back Road.
The Groudle River Trail can be accessed from the Clypse-e-Creer car park or alternatively drive along the Onchan to Laxey Road (A2) turning into the Begoade Road (B20) at the top of Whitebridge Hill. Continue on the Begoade Road to the Conrhenny Picnic area and car park. You can then walk into the trail via the Little Conrhenny Road.