Editor’s note: The following is the second of a three-part series that will run each week on the Recreation page. The stories discuss the historic flooding that took place across the state in 2019 and how it affected wildlife, state parks and fisheries.
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When the Platte River breached a levee separating it from a private sandpit lake west of Fremont, it sent floodwater flowing through that sandpit and washed out the embankment and road separating it from Lake 20 on the southwestern corner of Fremont Lakes SRA. Flows continued through Lake 20, washing out the bank separating it from Lake Leba, a private sandpit to the east.
That connection to the Platte allowed common carp, gizzard shad and other undesirable species of rough fish to enter the sandpit lakes. These species can disrupt an aquatic ecosystem by clouding the water or competing with game fish for food. Additionally, the flush of nutrients brought in by floodwaters can fuel algae blooms, another detriment to water quality.
Overland flooding carried rough fish into numerous public and private sandpit lakes along the Platte, Elkhorn, Loup and other rivers and streams in March, and again in July. Many of these lakes had undergone treatments to remove carp and had developed into excellent fisheries for largemouth bass, bluegills, crappies and other species. In many lakes, those treatments will have to be repeated to restore the fisheries. Once restocked, fish need at least three years to grow big enough to be coveted by anglers.
At Fremont, crews repairing the road along Lake 20 were forced to put culverts in to handle the water that continues to flow in from the Platte and through the lakes, putting work to restore the fishery in Lake 20 on hold.
Of the 20 lakes at Fremont, only two, Lakes 9 and 17, didn’t flood. It also appears that Lakes 1 through 8 on the park’s northwestern corner were spared from the reintroduction of carp. The rest of the lakes will eventually need to be renovated. Other work to improve water quality and fishing in recent years included the application of alum to tie up nutrients and control algae blooms. That work, which had been successful, may need to be repeated.
At Two Rivers SRA, all seven lakes flooded and now contain carp and other rough fish, including the Trout Lake. A renovation will be required there to maintain that popular put-and-take fishery. At Louisville SRA, all five lakes flooded but only Lakes 1 and 1A showed carp in sampling and will need to be renovated. Lake 2 may be treated to remove shad. Carp also found their way into waters at Memphis and North Loup SRAs and Ravenna Lake in March.
In early July, heavy rains in south-central Nebraska caused flooding on the Platte and Republican rivers and their tributaries. At Sandy Channel SRA near Elm Creek, floodwaters washed out the main road into the area, which also separated Lakes 4 and 8. The road was repaired and the park reopened in November. Dikes separating Lakes 1A and 2 from the south channel of the Platte were damaged. Carp invaded into four of the eight lakes on the area, including Lake 8, which had water quality high enough that it had become a popular site for scuba diving.
Near Kearney, flooding on Turkey Creek west of town brought carp and nutrients into sandpits at Yanney Park, Kearney Rest Stop, Kea West and Bufflehead WMAs, four Archway Lakes and numerous private lakes, all popular fisheries because of the quality and the proximity to the city.
Harlan County Lake, a U.S. Army Corps of Engineers reservoir, rose 11 feet into its flood pool, inundating campgrounds, boat ramps and other facilities, limiting access to anglers for the rest of the summer.
In the Sandhills, precipitation that was well above normal for the year raised the level of groundwater and that of the numerous natural lakes in the region. The flooding closed highways and county roads, making access difficult to some of these popular fisheries. It also flooded the cabins and concession at Big Alkali WMA, forcing the area to close for the year. While the campground has reopened, it is not known when, or if, the cabins and concession will reopen. With water levels high, plans to renovate more lakes on the Valentine National Wildlife Refuge were delayed.
A fish bypass built by Game and Parks’ Aquatic Habitat Program at Spalding Dam on the Cedar River was not damaged, but the historic hydroelectric dam itself was breached in March. The Gracie Creek Trout Pond at Calamus Reservoir SRA will have to be dredged to sand that washed in during the flood.
The Valentine State Fish Hatchery and the Grove Trout Rearing Station were both damaged by flooding in March. At Valentine, dikes separating several ponds were washed out and others damaged, and several hatchery ponds were filled with silt. At Grove, a diversion dam on the East Branch of Verdigre Creek was damaged, roads washed out and ponds filled with silt. To renovate and restock lakes where rough fish were introduced will cost an estimated $1 million.
As for the fish in other rivers, streams and reservoirs, the effects of the flood are yet to be known. Creeks in north-central Nebraska, including Long Pine, Plum and Bone in Brown County, flooded, but most structures that had been installed to improve habitat for rainbow and brown trout were not damaged.
On the Missouri River, increased flows through Lewis and Clark Lake and five upstream reservoirs likely moved fish through that system just as it did in 2011. After that flood, paddlefish, pallid sturgeon and walleye stocked above the dam were found below it. Farther downstream, extensive flooding for much of the year led to increased production of blue and channel catfish, sickelfin chubs, blue suckers and other native fish that were able to spawn in inundated habitat on the floodplain. Fishing proved difficult to impossible for anglers, as river boat ramps were underwater throughout the year.