Drought replenishes Long Meadow Lake

While everyone else moaned about the drought this summer, Minnesota Valley National Wildlife Refuge biologist Vicki Sherry watched water levels drop in Long Meadow Lake and rejoiced.

What was happening to the lake was visible to anyone who drove over the Hwy. 77 bridge between Bloomington and Eagan. Before recent rains, the water had dropped so low in some places that mud flats were exposed and the lake looked more like a collection of shallow pools.

Sherry said the 2-foot drop in water level was exactly what Long Meadow needed.

The 1,200- to 1,500-acre lake is a key stop for waterfowl on spring and fall migrations. But the variety of native plants in the lake had diminished with repeated flooding from the Minnesota River and water that was too high for some of the plants favored by ducks.

"We had too many water lilies, cattail and river bulrushes," Sherry said. "They're fine if you don't have them all in one place. But some areas were so choked with them that you couldn't even get through it."

Now, after a summer of low water that was helped along by nature and by a new water control structure that prevents the river from backing up into the lake, native plants like smartweed, arrowhead and beggar's tick have reappeared. The water is swarming with insects favored by ducks. And Sherry expects the roots of reestablished native plants that thrive in shallow water to help stabilize a lake bottom that had become loose from repeated flooding.

Trying to lower water levels

The refuge had little control over lake water levels until 2007 when the U.S. Army Corps of Engineers replaced old water gates with a new federally financed $805,000 control structure on the lake's main outlet to the river. Still, attempts to pull the water down last summer failed, stymied by heavy rains and beavers, which blocked the control gate.

Battling the dam-builders

Mother Nature cooperated this year, aided by a hard-working group of Youth Conservation Corps workers who battled the dam-building beavers through the summer.

Sherry said results were evident almost immediately. As the water level dropped, long-legged, needle-beaked shore birds like avocets and willets appeared on Long Meadow's mud flats in the spring.

"Those aren't something you see here every day," Sherry said. "The birders were very excited."

Now, dabbling ducks such as mallards, widgeons and blue- and green-winged teal have been moving through the refuge on their way south. Sherry said she expects to see diving ducks like hooded mergansers and ring-necked ducks coming through in a couple of weeks.

New vegetation thrives

While water lilies and bulrushes still populate the lake, the new diversity in lake vegetation is evident even from the shore, Sherry said.

She said it would be ideal if the water level could be held to 12 to 18 inches through migration, but the refuge isn't trying to prevent the water from rising at this time of year.

Since natural levees separate Long Meadow Lake from the river for much of its length, there is little the refuge can do to prevent the river from flooding the lake if river levels are high enough. But Sherry said she hopes that new lake plants are established enough that water levels might have to be drawn down only once every three to five years.