Build Your Own Trout Lake

By Gary Lewis

Gary Lewis Books and DVDs

Some people, when they have enough resources, move to fishing water. They build a cabin on their favorite lake or buy riverfront property. Many leave the landscaping in its natural state and use the time they would have spent mowing the lawn out in a rowboat or float tube. And they smile.

But there's another way. You can build a trout lake on your own property. Roger and Cindy Grossmann know what it takes to build a trout fishery on dry land. "You have to have a healthy budget, a lot of time and a lot of imagination," Cindy said.

Grossmann's son and daughter-in-law, Keith and Summer Grossmann, bought their piece of the Central Oregon's high desert in 2004. Cindy Grossmann would manage the project. The 206-acre parcel west of Redmond and east of Sisters was planted in alfalfa. 128 acres of ground was irrigated by a pivot. The rest of the land was in sagebrush, junipers and rimrock. Deer and elk moved on and off the property and coyotes hunted the fields, but there wasn't a fish to be found.

Keith and Summer set about to change that. Looking at the mountains to the east and to the west, they imagined a homesite and thought that what the place really needed was a lake.


Water wasn't the problem, Cindy said. There was plenty to irrigate the 128 acres of alfalfa. The problem was keeping the water in one place. "You have to get the water from somewhere. A domestic well won't cut it because there are limitations on how much you can pull out. You can build a small pond for koi (or bluegill) and run it with domestic water, but a trout lake has to be deep so that trout have the temperature they need to survive."

The first step is securing the water and the right to use it. The State considers Grossmann's private lake an irrigation reservoir with recreation use. A lot of public waters fall into the same category.

To feed their lake, the Grossmann's would use the irrigation well and move the water with a 100-horsepower pump blasting water through a six-inch line into a sump pit, which would, in turn, spill into the lake.


In flat ground, it's easy to just dig a hole, line it and fill it. On the Grossmann's property, it wouldn't prove to be that simple. Most of the land slopes off toward the Deschutes River, a half-mile away.

Without touching the alfalfa field, the Grossmann's reckoned they could build a lake that would hold eight surface acres, which would allow plenty of escape cover for big rainbows. Berms and dikes were built to control the water. An earthmover, a bulldozer, a backhoe, an excavator and a dump truck were on site at the same time. They built the berms first then kept hauling, digging and sculpting, while a survey team checked their work by shooting elevations.

When the big hole was finished, they installed an overflow pipe, one of the most important features of any water storage project. "You need to be able to siphon off excess water in the event of heavy rains," Cindy Grossmann said. "Know and plan where that water is going to go." A carefully placed overflow pipe can protect the dam.


The next step was to pick out the sharp rocks. All the sharp shapes had to go. It was important to remove rocks that could puncture the 24-mil vinyl from beneath.

In sandy soils, Cindy Grossmann believes in installing a positive liner rather than sealing with clay. "We wanted to use a sealing agent, so we didn't have to use a liner, but the Central Oregon soil wouldn't bind with it."


Installing the liner for an eight-acre lake was no simple task. 20 guys were needed to put the vinyl in the ground. A trench was dug high above the proposed water's edge and the liner edges were laid in the trench. A Geotech secondary liner was laid in the trench and extended eight feet below the waterline to protect the vinyl from ultraviolet rays, animals, friction from boats, vegetation growth and anything else that could puncture the vinyl.

"When you're forming your lake," Grossmann said, "you want to avoid perforating the liner. You do have to weld around the pipes, but the fewer perforations the better." At Boulder Lake, Grossmann poured sonotubes for piers, in case she wanted to install docks later. The concrete for the boat ramp was poured over the liner.


With the boat ramp and piers in place and the trench backfilled above the waterline, it was time to build habitat. Grossmann's team hauled in huge boulders and piled rocks on top of rocks to give trout places to hide. They dropped tree trunks in several places to establish better insect production. Though there were plenty of junipers around, they avoided putting junipers in the water because of the acids in the wood.

"We wanted to avoid planting vegetation that would penetrate the liner," Grossmann said. "We wanted to keep the lake as clean as possible. Besides, nature would seed it by the wind and whatever birds might carry in."

Through the middle of the lake, they built a false road bed to create structure for fish and a place for burrowing insects to find cover and multiply.

It was time for the earth moving machines and the heavy equipment to head back to town. Cindy threw the valve to turn the water on.

Each morning, the level was higher and soon the hole in the ground was a puddle and then a pond and then a lake.

"One of the most exciting things was how fast nature took over. It seemed like it was the first morning after we started putting water in the lake that there were tadpoles," she said. "The tadpoles were there the next day. That was the most surprising thing. I don't know where they came from. It wasn't from the well water."


For trout, the water needs aeration. The challenge is to get oxygen into the water. Without a free-flowing inlet stream, the surface gets too warm and weeds begin to grow. And starved for oxygen, the trout will die.

There are options. At Boulder Lake, Grossmann opted for two big motors to pump in air. A four-inch perforated pipe delivers the air to every corner of the lake. The pumps and pipe were installed by plumbers from H&H Pump in boats and scuba gear.

Another way to put air in the water is with a water feature. Grossmann did this with a 3-hp pump that circulates water out of the lake and runs it back in through an artificial creek about 50 yards long. If she had it to do over again, she'd make the creek a little narrower, she said, and deeper to allow the fish to move up and spawn. And, she'd build a series of benches near the moving water to encourage spawning activity.


It was the fall of 2005, cold water lapped at the overflow pipe. The hatchery truck backed down the boat ramp and the operator turned the valve on the hose. 400 six-inch triploid rainbows, hit the water. They arced above the surface, splashed and flashed, frenzied, as if they were happy to be home after a long ride in the truck.

"Along with the fish, we put in freshwater shrimp," Grossmann said. "We packed them out in buckets and poured them into the lake at several different points. They lie in the rock ledges and multiply and feed the lake."

If the size of the pocketbook doesn't match the imagination, perhaps a smaller lake is in order. Trout don't need a lot of room to thrive. With a little work, you can build your own trout habitat, even in an area of 200 square feet or less.

Late last September, my dad and I brought 14-year-old Nolan King and his 11-year-old brother Sam out to Boulder Lake. The days were growing shorter and the nights were getting long. The trout could sense they were running out of time to put on weight before winter. They charged the boy's Rooster Tails and went airborne when they felt the steel. Dad and I caught our fish on a No. 14 Parachute Adams. The triploids averaged 17 to 20 inches long. There were smiles all around.

As the sun went down, mule deer appeared out of the junipers. Skeins of geese drifted across the sky. Mallards wheeled above the eastern end of the lake and coyotes howled from the rim. For a few moments, the lake was dead calm. I listened hard, but I couldn't hear a lawnmower anywhere, just the splash as Sam made one last cast. Then Sam shouted "I got one," and his drag screamed.

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