Torrential downpours that brought six inches of rain resulted in severe flash flooding in Livingston Manor, Roscoe, Liberty, Parksville and Callicoon. After reaching heights of more than ten feet, with the Beaverkill coursing at 60,000 cubic feet per second, and the Willowemoc just shy of 8,000 cubic feet per second early last Wednesday, floodwaters in both have receded.
Rivers and streams, even those that are well-familiar, have changed significantly. If attempting to enter a stream, be especially cautious and aware that there will be areas containing slippery deposits of silt, sand and mud, requiring the use of a sturdy stick or wading staff. Stream banks may have eroded, causing access areas to be heavily undercut and reconfigured.
Receding waters have left behind a maze of newly submerged brush, fallen trees, and trash piles. New slack areas of grassy or shallow backwaters have appeared, some which may contain fish that were displaced from the main river. As the rapid currents begin to slow, fish may have stacked up in these calm backwaters, side channels, and eddies to avoid remaining heavy flows while still taking advantage of passing food.
In some areas “mud lines” (distinct visible edges where murky, stained water meets cleaner water) provide an ideal location for predators to hide. And as muddy waters clear, the scouring of the stream that has occurred is readily apparent, with the stream taking on an almost “milky” appearance, in some areas with familiar moss-covered rocks now stripped clean, bare logs and trees uprooted and displaced.
Despite what some may think, adult trout are not usually swept downstream during a flood. Rather, they enter their survival mode and will instinctively ‘hold tight’ at the bottom, as friction against the rocky riverbed greatly slows faster-moving surface floodwaters. Trout may also seek refuge outward, along the edges of the stream or in sidestreams and newly-flooded grasses and bushy areas, where the currents are not as intense. As can be imagined, heavy downpours will wash tremendous numbers of worms, grubs, and terrestrial insects, such as ants, grasshoppers, crickets, and spiders directly into the water, providing plenty of food and nutrition for the fish. However, although most adult trout will survive, floods can be devastating to the next generation to come, with many young-of-the-year troutlings and fingerlings being swept away.
Here in upstate New York, where the rainbow trout have spawned and laid their eggs in late March through late April (and early May in colder waters) the tiny former alevins are still in a vulnerable stage and are very susceptible to flooding and being swept away. In addition to high mortality of the fry that would become next year’s rainbow trout, there is also the risk of trout being trapped in those temporary side pools and puddles off of the main streambank, leaving them vulnerable to predators or death as the backwaters and puddles dry up.