RESURRECTING OREGON'S POPULAR FAMILY-FRIENDLY DIAMOND LAKE

June 03, 2008 11:00 pm
Bailey Bornheimer of Cortvallis holds a stringer of trout she caught this time last year at Diamond Lake, located 80 miles east of Roseburg (The Pilot/Larry Ellis).
Bailey Bornheimer of Cortvallis holds a stringer of trout she caught this time last year at Diamond Lake, located 80 miles east of Roseburg (The Pilot/Larry Ellis).

By Larry Ellis

Pilot staff writer

There are going to be a lot of kids growing up thinking that catching a fat 15-inch trout is the norm. That's because Diamond Lake, Oregon's most popular family trout destination two hours east of Roseburg and five hours from Brookings, has been resurrected – for the second year in a row.

It seems unfathomable that a lake with 50-feet visibility could ever become as cloudy as a stained-glass window, but that is exactly what was happening to Diamond.

There wasn't one reason you could cite why she was becoming so opaque – there were 90-million of them, and they were called tui chub.

To comprehend how a fish could have such a potent effect on water clarity, you have to understand the nature of Diamond Lake.

Diamond is what you would call a hatchery in and of itself. The Oregon Department of Fish and Wildlife (ODFW) never needed to stock fully-grown trout into her waters. Raising thousands of fish to 8 inches or larger can be very expensive, not to mention time consuming. So ODFW decided to let Mother Nature do her thing.

At a far less cost, ODFW could raise fish to the 3-inch fingerling stage. One hatchery can raise hundreds of thousands of fingerlings in far less a period of time than it takes to raise them to catchable size.

And that's exactly what ODFW did with Diamond Lake. With perfect conditions, a 3-inch fingerling can grow 2 inches a month. Those conditions are an abundance of zooplankton in the water, tremendous bug hatches, and a long growing season. Diamond Lake meets all three requirements.

Fingerlings thrive on zooplankton for the first few months of their life, then they slowly switch over to eating insects. Trout derive over 80-percent of their protein from insect life. And Diamond Lake literally has tons of it available, at least 125-pounds of insect life per acre.

Then some yahoo stuck a pair of tui chub into the lake. Once tui are introduced into a waterbody, the system is doomed. They are prolific breeders. They are also plankton-eating machines.

Plankton eats a lot of stuff that makes lakes get cloudy, stuff like algae. Once the plankton was eaten up, algae took over and clouded up the lake. It also created more toxic algae blooms, a condition often unsafe for animals, children and adults.

With practically no zooplankton, it also didn't serve a useful purpose to plant any more fingerlings, so ODFW reverted back to stocking catchable size rainbow trout again, as well as the predacious Williamson strain rainbows from Klamath Lake. The Williamsons did eat some of the chub and grew to almost 20 pounds, yet the chub just kept on multiplying. Something had to be done.

Diamond Lake treated

In September of 2006 ODFW treated Diamond Lake with rotenone. Rotenone is a natural substance derived from the root of a legume that is toxic to fish. When applied, it dissipates after six days. People would have to wait until the 2007 opening day of trout season to find out if the water would ever clear.

It cleared even faster than anyone had anticipated. Within two months, Secci disc readings showed water clarity greater than 20 feet, later attaining 50 feet of visibility as it had originally. ODFW began a massive stocking schedule into the lake.

Last year's new and improved version of Diamond was hard to beat, with limits upon limits of fish in the upper teens biting the dust. But this year, the water is going to be so crowded with monster trout it's going to be a zoo. Here's why:

•78,000 trout between 12 and 26 inches were stocked in 2007. At least 25-percent of those brutes survived.

•100,000 3-inch fingerlings were planted in June of 2007. By November they grew to 11 inches (remember that fingerlings are now eating the plankton that the tui chub robbed them of). At least half of those fingerlings made it. Those fish averaged about 15 inches on opening day when anglers were fishing through the ice, and they were fat suckers. They could be 16 inches by now.

•6,000 1-pound predacious Eagle Lake trout were stocked in September. Those fish could be 16-plus inches this month.

•Another 43,000 fish, many of which were between 12 and 18 inches were jammed into the lake by May 31 of 2008.

•3,000 of those fish were between 2 and 4 pounds.

•6,000 more fish were stocked last week.

•Another 6,000 will be stocked this week.

•15,000 predacious Eagle Lake trout will be stocked in July.

•200,000 more fingerlings will be stocked in June.

•In November there were more than 125 pounds of insect life per acre in this natural hatchery. This year that figure will probably rise even more.

•Does the sign, "Don't pet the animals ring a bell?"

While many people look down their noses at planted rainbows because their meat is not as firm as native fish, only 6 months after last year's trout were liberated, they adapted to the insect life surrounding Diamond Lake. While many of the fish lost a few ounces, they became firm-meated delicacies in the process.

And since over 20,000 of those original trophy planters survived, you can expect some larger 'bows to come out of the lake.

"Someone's going to catch a 10-pounder this year and have the modern record after the treatment," says Rick Rockholt, Marketing Manager for Diamond Lake Resort (www.diamondlake.net).

Already anglers have been catching some fish over 4 pounds from last year's stocking. Those fish probably weighed between 2 and 3 pounds when they were first planted.

So what can you expect if you go to Diamond Lake this weekend? All-in-all, the prospects are looking pretty darned good.

"We're going to be looking at excellent fishing for the month of June," remarks Rockholt.

In the beginning of June, five-fish limits were the rule, not the exception.

Why are the fish so hungry?

Last winter was brutally long for Diamond Lake, so much that the lake didn't completely thaw until a few days ago. Now that the water's starting to warm up, they would probably eat a Zippo if one fell in the water.

And this weekend is the perfect chance to bring home a stringer of fat rainbows to feed the clan because June 7 and 8 is free fishing weekend. You do not need a license or a tag to fish in Diamond, or any other Oregon waterbody for that matter.

Where you catch fish at Diamond will depend largely on whether they are hatchery or holdover fish. Hatchery fish are used to hugging the sides of a raceway, and being fed on the surface, so look for the planters to be near the surface hugging close to shore between 10 and 20 feet of water depth.

"You don't need a lot of weight because you want to fish in the top 10 feet of water when you're trolling," adds Rockholt. "Remember, these fish are just coming out of the hatchery, so they're not going to be down in the bottom of the lake. You're only going to be about 50 yards from the bank.

"From Short Creek all the way up the eastern side of the lake to the resort is all good trolling," notes Rockholt, who suggests using a bright Needlefish or an F4 frog-colored FlatFish.

A great baitfishing hole is directly out from the Thielsen View Campground, and about one-half mile south. This is the old Shrimp Hole.

"The entire south end of the lake between 10 and 15 feet of water is all good trolling and good bait fishing," tips Rockholt.

Good bank fishing is in front of the resort, at the Cheese Hole and along the eastern shoreline. Another great bank fishing spot is on the southern jetty at the north boat launch.

About the best bait on the lake is good old rainbow PowerBait fished from a sliding sinker set-up, but don't be caught without brighter colors like chartreuse and fluorescent orange. Pautzke Green Label salmon eggs fished under a slip bobber is also an excellent choice.

For the holdover 'bows, Rockholt advises using night crawlers.

With all the insect hatches going off, fly fishermen can also have a blast in Diamond Lake. But you don't have to use fly fishing gear to use flies on this lake.

Slow-trolling olive Woolly Buggers or black ants about 150 feet behind the boat with a slit shot or two, 20 inches ahead of the fly can often be deadly. When a trout hits a trolled fly, they practically knock the rod out of your hands.

"A lot depends on what kind of growth is on the bottom of the lake," adds Rockholt. "Where the insects are, are where you're going to find the fish."