RIVERDALE A fish hatchery with a water problem is not a good thing. The intake that supplies water for 40 outdoor rearing ponds at the Garrison Dam National Fish hatchery is high and dry. Dry too are the ponds that are vital to fish stocking programs in North Dakota.
"We've got a serious intake problem," said Rob Holm, hatchery project director. "If we can't get water to those acre-and-a-half ponds, that's two-thirds of our walleye and pike production for next year. We'll be in the neighborhood of losing probably 6 (million) or 7 million fish."
The ponds are drawn down in the fall after the fish raised in them have been removed for stocking. Water is pumped back into the ponds as needed in the spring. However, the pond intake pipes that draw water from the Spillway Pond located east of hatchery remain 15 feet above the waterline.
Kim Fundingsland/MDN - - These are the intake pipes that supply water to outdoor ponds at the Garrison Dam National Fish Hatchery. They remain well out of water at the Spillway Pond.
The problem began when the U.S. Army Corps of Engineers opened the spillway gates at Garrison Dam for the first time in history earlier this year, a move thought necessary because Lake Sakakawea was filling. The released water poured down the concrete spillway and into the Spillway Pond below. Initially there was some over-land flooding when the pond over-filled. That problem was alleviated naturally when the current from the releases cut entirely through the Spillway Pond, tore through the woodlands beyond and back into the Missouri River. Once that gap was opened the Spillway Pond dumped rapidly into pinto the Missouri.
"The Spillway Lake used to sit 15 to 20 feet higher than the river. Now that the Spillway Lake is connected to the river it is the same elevation, which puts our intake itself out of the water by 15 feet," Holm said.
Several remedies are being explored in the hopes of finding a way to fill 40 outdoor ponds next spring. The problem is there may not be enough time or money to implement a solution in time to meet hatchery expectations next spring.
One option under consideration is the construction of a berm where a road previously existed below the Spillway Lake. However, replacing the roadway would essentially mean construction of a dam. Building a dam requires numerous paperwork and studies that would likely result in a lengthy delay before construction could begin.
Pumping water over-land into the ponds would require several very large pumps, if they can be secured next spring. The efficiency of that method is questionable, says Holm, but it already being explored. Another possibility is excavating out a deep holding pond near the Spillway Lake, pumping water into it and then into the holding ponds.
"We could excavate to the current water level and add vertical surface pumps," Holm said. "We'd have to pump water twice but at least it would be available."
Water for the ponds on the west side of the hatchery grounds comes directly from Lake Sakakawea. That water is much cooler and is used for cold-water species of fish or those that rely on a completely different food source. Pumping that water into the east ponds is not considered an option for raising pike and walleyes because of the lack of proper zoo plankton.
"It's pretty critical that we actually tap back into that water source below the spillway," Holm said.