Canal and river outfalls can be either very bad or very good for fishing.
Outfalls are water discharge pipes from factories, power stations and sewage works. Common on rivers and canals all over Britain, their effect on fishing varies from the disastrous to the greatly beneficial. It all depends on exactly what the water being discharged contains.
Rivers and their banks have always been attractive sites for all kinds of industrial activity. In the days before road and rail they were essential highways for transport- ing both raw materials and finished products, so factories were frequently built as close to them as was possible.
The navigable network of waterways was extended by building interconnecting canals, whose banks then proved equally attractive to industry.
Furthermore, canals and rivers were — and still are – ready sources of the often huge amounts of water needed for all sorts of manufacturing processes.
In the past, when there were few if any government pollution controls, factories and sewage works simply used rivers and canals as convenient drains for their untreated waste water.
Nowadays this sort of behaviour isn’t so easy to get away with, thanks to much tighter pollution controls. Unfortunately, however, there are still some places where toxic waste from factories and untreated sewage pour into our waterways. This makes them poor fisheries at best, completely lifeless ones at worst.
Rivers and canals
Outfalls on rivers and canals of interest to anglers are those that discharge clean or relatively clean water. Treated sewage outfalls sound rather unpleasant but they can be excellent places to fish. It may be that the water they discharge contains some microscopic food forms, but more importantly it boosts flow, raising the oxygen level of the water, and also adds colour. In summer especially, when the natural flow may be slight and the water quite clear, such outfalls attract all sorts of fish.
Warm water outfalls are also attractive. In summer they boost flow, if not colour, but it’s in winter that they really come into their own. The warm water then acts like a magnet. In very cold weather the swims immediately below warm water outfalls can be the only places where the water is warm enough for fish to feed. On much of the Trent, sport is often better on weekdays than at weekends, and this seems to be because the power stations lining the river don’t discharge so much – if any – warm water on Saturdays and Sundays. Food processing plant outfalls can be brilliant places to fish. The water they discharge is not only usually warm, it often contains titbits of food. If the water is cloudy rather than clear, so much the better. Make sure you know what kind of food the plant is processing – ifit’s something you can put on the hook, it makes sense to take some samples with you, if only as a change-bait.
Outfalls on still waters are rarer than on rivers and canals but can be just as attractive to fish. The most common type is the factory outfall, but there are a few places where water from an adjacent river is piped into a lake or reservoir, either to alleviate flooding or to maintain the still water at a more or less constant level.
As with river and canal outfalls, still-water outfalls are most attractive to fish at the height of summer and in the depths of winter. In times of drought in summer the oxygen content of a still water can get very low, so any outfall oxygenates the water in its immediate vicinity. Fish therefore quite naturally gather there.
Even when temperatures are at rock bottom in winter, and the rest of the still water is frozen over, an outfall keeps an area ice-free. Because the water is moving it is always slightly warmer, whether it is from a factory outfall or is piped in from an adjacent river.
The fish most commonly attracted are roach, perch and pike, but anything can turn up – even tench and carp. More often than not you find the smaller fish right in the main flow and the bigger ones hanging around at the sides.
Don’t get carried away with the idea that the fish attracted to outfalls are easy pickings and can be caught any-old-how. Outfalls are always popular places, so the fish are subjected to particularly heavy angling pressure and learn from being caught. Skilful feeding and bait presentation are needed, just as they are anywhere else that is heavily fished.
Bear in mind, too, that because outfalls are so popular, you often have to get down to the water at the crack of dawn to secure a pitch — even in the middle of winter, when it’s not unusual for anglers to ‘bag’ a swim with their tackle, then sit it out in the dark until it gets light enough to start tackling up! This is especially true at weekends, of course, but even on weekdays outfall swims can become crowded.
How close you need to place your bait to the outfall depends on how much water it discharges. A large river outfall might boost the flow and colour the water for several hundred metres downstream. A small pipe discharging a steady trickle into a canal, on the other hand, may only affect one or two swims in the immediate vicinity.