Longitude: 6,7 km.
Annual average flow: between 55 and 60 m³/sec.
Whit a lovely anatomy and full of big trout, it results the star river of the basin. Along its short route it joins Rivadavia and Verde lakes. Its inlet is like a big and deep funnel, and with an extremely light current, with heavy underwater vegetation. Against of the dense wood that surrounds it and complicates the tries, it becomes ideal to try with dry fly, mainly during hatching and oviposition of caddis, frequently in the afternoon.
At the junction with Colehual river (its main tributary and one of the more important spawnery in the National Park) there appear the first riffles and runs, these latter mainly of anatomical shape. The Rivadavia river is a course, which distinguishes itself by its varied configuration, divided into many branches. It is surrounded by exuberant wet forest, composed of huge coihues, lengas, caña colihue and a few retamos.
Because of the density of the vegetation around and its volume of flow, this is a difficult river for fishing and wading through, especially at the beginning of the season. That is why it is advisable to try by mid-December, with pneumatic shafts. For those who enjoy fishing wading, the end of the season results the most appropriate time for taking the most advantage of light- technique fishery.
The Rivadavia river bears two very special features. The first one is that its bed is covered by endless number of logs, which tend to pile up over the deepest coast. Each of them often result in the shelter of many trout. The second feature is the number of small branches and tributary spring creeks, which allow exceptional fishing on sight with ultra light equipment.
The rainbow trout is the predominant specie, and the catch of any other species is a less frequent fact. On the contrary, in its tributary rivers (like a Mallin spring creek) there are also brown and brook trout. This river stands out by its abundance of fish and its excellent average about 16 to 22 inch, catch smaller than 13 inch is unusual. Fish of a 24 to 26 inch, especially with high waters and using streamers.
Food source
The most salient feature is the lack of macro crustacean organisms (pancoras and crayfish). Though not as productive as the other rivers of the northern region, it has an interesting variety of aquatic insects. The important orders are the ephemeroptera (especially Meridialaris and Amaletus genus) and cased caddis (Glossomatidae family). Though plecopterans are less frequent, there are samples of good size.
Something different is the small branches and spring creeks. There, exceptionally appear scuds of Hiallela genus, midges and zooplankton of good size (water flies and copepods). Also, we find Baetis nymphs (little blue wing olive), which may surprise us for their too fine hatch.
The large number of juvenile trout suggests that under certain circumstances they may be an important contribution of proteins. Terrestrials insects are not significant except for the coleopterans and tree bugs typical of the forest, which may be somewhat important.
Equipment and fishing techniques
The most suitable fishing techniques for this river are those implying the use of small streamers, nymphs and wets. Though not always a hatching of aquatic insects it may provide an interesting site for dry fishery. The best opportunities with dry banks are found in deep and gentle depressions trying from a pneumatic raft. Among the most efficient flies there are Woolly Bugger Peacock, Prince, Casual Dress, Brown and Peacock, Ida May, Jabali Nymph and Soft Hackle Marabou (from No.8 to No. 16 according to their model). The attachment of bead heads, rubber legs and some brilliant items is advisable especially with rather agitated fish of the start of the season. On the contrary, with the increase of the fishing pressure it becomes essential to reduce flies and especially trim tippets to maximum. In its arms, imitations of Scuds, Serendipity, Midges Pupas and delicate Soft Hackles in No. 14 to No.22 hooks tied to tippets not larger than 5X are recommended.
The Rivadavia conditions make fishery on sight, with a less profitable prospecting. The best try is often in the pockets waters formed by each log – favourite shelter of the typical rainbows in the area. In most places roll cast and polarised glasses are essential. All-around equipment to go fishing in the river is a No. 4 or 5 with a WF floating line to get a better control and mending of the log groups. Minor arms allow the use of equipment under No.3 all year round.
Environments of complementary reading: Manso, Grande (Chubut) and Nilson rivers.
Access: from Cholila village along Provincial Route No.15 as far as the junction with Provincial Route No.71 (a 3-km’s drive). From there we have a 37-km’s drive along this latter southwards as far as the river mouth on the lake Rivadavia. It is also possible to reach other places of the Rivadavia River from several car-drives, which leave from Provincial Route No.71. The road is completely debris in regular conditions of maintenance.
Regulations: fly fishing only, catch and release and barbless hook.
