What Does Rain Actually Mean for Fishing?

It is finally starting to rain around central Virginia, which is great! We are in a historic drought and I don't need to point out how bad that is for grass, plants, everything growing—and it is bad for fishing. The recent fairly steady rainfall will help everything. With rain in the forecast for the upcoming weekend and into next week (which is great!) we wanted to lay out some hopefully helpful thoughts on what rain actually means for fishing.

Over the last 10 days or so, we have gotten between 1-2" of rain based on various gauges in Albemarle County. In the Shenandoah Valley, there are gauges that show 2-4" of rain from over the same period. The forecast is calling for another 1-2" of rain over the next week around Albemarle as well!

The obvious answer to the above question is: rain means higher water levels which are generally better for fish and for fishing in both rivers and ponds/lakes. We measure river water flows in the amount of water moving in cubic feet per second (CFS). Low water in rivers means less flow (lower CFS) which results in a) less oxygen for fish, b) habitat loss, c) potentially more concentrated contaminants and d) fish can actually become more susceptible to disease.

Fish are spookier in low water, move less and in some cases eat less--while warmer temps are clearly bad for trout, but good for bass. As a reminder, we do not recommend fishing for brook trout in water above 65 degrees. Rainbows and browns are generally a little bigger and tougher, but anything above 68-70 is not safe to fish them either. In warmer water, you can hurt or even kill trout if you catch them.

The recent rain has been fairly steady which is also good. The forecasted 1-2" for Albemarle (and more in the valley and surrounding areas) is expected to fall over a 5 to 6 days, which is the kind of steady rain we like to see. Rain over a period of time enables the water to be absorbed more effectively in the water table and flow more evenly into the rivers. Concentrated heavy rainfall in a relatively short period of time can cause surges in river levels as you can see in the chart and table and that we experienced in the period from May 18th to May 28th.

Rapid rises in river water levels can be unsafe. An inch of rain can cause a river to rise a foot or more in smaller rivers, and rivers can rise quickly with heavy rain and can flood. Even larger rivers can move significantly with dense rainfall, as can be seen in the chart on the James and Shenandoah rivers--and even the Jackson, which is a tailwater release river.

For those that want to monitor these bigger river levels, its a good idea to look at gauges on tributaries of the bigger rivers to get a sense for how those waters will react to rainfall. As a side note, the dam release tailwater generally means more regulated flow as can also be seen in the table for the Jackson river. The Jackson CFS has remained in the 230-250 range outside of the one big rain event, while most of the other rivers have moved lower through the dry conditions (until last week's rainfall).

More water means better flow, more oxygen, more food moving for fish to eat and more places for fish to move. The general rule of thumb is, fishing is better when water is stable or coming down than it is when water is rising. Water can rise quickly with rain, which can be dangerous, visibility can worsen, fish eat less and they can move into protected hard to fish areas.

After heavy rains, it is best to just stay away from moving water. While the fishing is not good, more importantly, it can be really dangerous as noted. Don't ever drive through or walk into rapidly rising creeks or rivers as that can be deadly.

When water is falling, visibility improves, fish eat more and re-establish in feeding lanes. After a short period of rain that drives a rapid rise, rivers can also fall fairly quickly. The graphs and tables show this as well. After surges, water tends to hold for about 3-5 days. If there are longer periods of sustained rain, which we have experienced, water levels can hold longer.

In conclusion, the recent and forecast rain is good for the fishing and should provide some great conditions over the next several weeks. Since we have had fairly steady rain, and should see steady rain, hopefully the rivers will hold for awhile. Falling conditions can be good for fishing as well. It's bass season, and we have the best selection of bass flies we've had in years at the Albemarle Angler, as well as great bass rods, reels, line, or new Angler sun shirts and everything else you need. We are also booking guide trips for the rest of the summer!