Fishing the Upper Lliedi Reservoir (Swiss Valley)

Fishing the Upper Lliedi Reservoir (Swiss Valley)

If you wish to fish in the Upper Lliedi Reservoir (Swiss Valley) then this article will provide you with some useful tips and advice. Firstly though, let me provide you  a brief history of 'Llanelli Angling Association' who are responsible for the fishery management.

Llanelli Angling Association.

The History

Llanelli AA was founded in 1902 and the club water has been the Upper Lliedi Reservoir since its inception. The focus of the club has been on fly fishing for trout.

Early 1970 the Llanelli and District Water Board was taken over by the Welsh National Water Development Authority. Club permits were increased over a two year period from £12 to £120: this had a disastrous effect on club membership when it went from 90 members down to 24. The water authority could not continue the stocking policy and they wanted to close the fishery and they renamed it a wilderness fishery.

Llanelli Angling Association together with the Llanelli Borough Council took over the running of the reservoir and continued to do so until the Llanelli Borough Council became the Carmarthenshire County Council.

The fishery is now managed by Llanelli AA.

As a non-profit making organisation all permit money is used for the stocking of fish and the upkeep of the reservoir.

The club membership has expanded from under 30 members in the 1970`s to the present membership of circa 130.

The club is affiliated to the Welsh Salmon and Trout Angling Association and we have a number of both junior and senior Welsh internationals members of the club who have developed through the club activities. The club has always practised an `open policy` and encourages all, including junior and disabled anglers.

Upper Lliedi Reservoir 1

The fishing

The Upper Lliedi Reservoir provides top class fly fishing all year round for both the novice and the experienced angler. From the early season booby fishing to the autumn dry fly fishing for the fish taking midges on the surface. I have learnt a great deal fishing at this reservoir, especially how to fish nymphs because from April through to June the fish feed extremely hard on the fantastic hatch of buzzers and other insects which hatch in their thousands every year. The bottom half of the lake offers some very deep water right at your feet which often means there is no need to cast to the horizon as fish patrol the ledge around 10 yards out.

Early Season   

At the start of the season Llanelli Angling Association stock the reservoir with a very good number of fish, this is often when the reservoir fishes the best. With very cold temperatures this time of year and not a lot of flies hatching, the fish tend to feed deep in the water column. The best way to target these fish is with Di 7 fly line (a fly line that sinks 7 inches a second) with two boobies on a cast spread around 6ft apart and 4ft to the first fly. Let your fly line sink right to the bottom and retrieve your flies very slowly with a figure of 8, you will receive a lot of taps and knocks when fishing like this but don’t strike until the line goes solid! The whole of the Upper Lliedi Reservoir fishes well this time of year and the hot flies are a Cats whisker booby, Viva Booby, Tequila booby and a gold head damsel.

Upper Lliedi Reservoir 2


This is my favourite time of year to fish the reservoir as fish start to turn their attention to the big hatch of buzzers which happens at the Upper Lliedi Reservoir every season. One of the best spots this time of year is at the top of the lake around pegs 1-3, the water is not as deep as around the damn area and the water warms up quicker, as a result the insect life is more prominent. My set up for targeting these Buzzer feeders is either a floating or 3ft sink tip fly line, along with an 18ft leader with 4 buzzers or Diawl Bachs (depending on how deep the fish are), my flies are spread 4ft apart and 6ft to the first fly. If you struggle to handle a long leader with multiple flies that’s not a problem, another fantastic way to fish is to fish a single heavy weight buzzer under a strike indicator and keep changing your depth until you start getting takes. It’s key this time of year to fish your flies very slowly or static just keeping up with the slack line in your.

Upper Lliedi Reservoir 3


Summer can offer the most challenging fishing at the reservoir, the water temperature rises and fish retreat to the depths. The fish get stressed in warm water and as fish have no eyelids they try to get out of the sun by going down deeper in the water. Even though fishing can be challenging this time of year the fish are still there to be caught, the most productive time to fish in the summer is early in the morning when temperatures are at their lowest and late at evening when the temperature starts to cool again. In summer I find the fish tend to feed at the top of the lake around pegs 1-4. Fish feed on the hatching buzzers, shrimps and fry so I find that one of the best methods is fishing the “washing line”, this is where you have a point fly like a booby or a Foam Arsed Blob (FAB) on the point and flies up the cast such as Diawl Bachs, Cormorants or Crunchers. I like to start with a Sparkler booby on the point which causes a disturbance in the water and also imitates a little fish (fry) and 3 Diawl Bach’s up the cast with either pearl cheeks or a red holographic head which also imitates fry but also looks like hatching buzzers, I will start on a floating line if there is a light wind, if there is a strong wind then I will fish either a 3 or 12ft sink tip to pull the flies under the surface and anchor them down.

A typical Swiss Valley Fish, Fully finned and hard fighting.

Midday in the summer, fish will go back into the depths and sulk there until the sun dips behind the stunning scenery and the temperature drops. The fish can still be caught by reverting to early season tactics fishing with fast sinking lines and boobies, it’s also worth fishing a large fry pattern such as a humongous or a snake on a sinking line varying the retrieve, this can often throw up some of the larger specimens which swim in the depths searching for fry to eat.

Upper Lliedi Reservoir 4


When Summer ends the air and water temperature drops, the fish then come out of the depths and start to feed heavily again. This is a very exciting time of year as fish are very active on the surface either feeding on the hatching buzzers or smashing the fry shoals in pods. In the Autumn I like to fish high in the water, going no deeper than an intermediate fly line. If it’s overcast and a light ripple I like to fish high in the water with emerger patterns shuttlecocks, shippmans buzzers and diawl bach’s tied on light wire hooks to keep them in the surface. I would fish these flies on a copolymer leader as copolymer is lighter than fluorocarbon and stays up in the water surface and does not pull your flies deeper. The second way to enjoy fishing in the autumn is to fish for the fry feeders, this can be very exciting as you will often see the fish chasing your flies at a rate of knots and the takes can be savage so I would recommend slightly stepping up your tackle, I would recommend using at least 10lb fluorocarbon and the hot flies are a Humongous, snakes, Minkies and Zonkers fished either on a floating line or an intermediate. Fish tend to spread all over the lake this time of year so any spot can produce the fish.

Tight lines


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