Building Jim Swanson’s Lake Part II
Building Jim Swanson’s Lake
By Bob Lusk with Mike Otto
This is the second of a three part series about a private lake building project in Texas.
Jim Swanson’s sixty acre tract of north Texas land was primed and ready for a lake to be built. With planning and due diligence done, maps and renderings in hand, engineering complete, it was time to bring in the heavy equipment. Mr. Swanson is decisive and when he’s ready to pull the trigger on a project, his crosshairs are squarely on target.
Heavy equipment operator and lake builder extraordinaire Lupe Resendiz cleared key parts of the land with the bulldozer and the site was prepared for some serious earthmoving. Contractor Mike Otto had blessed the plans and Mr. Swanson was waiting and ready to go.
After Lupe cleared the area of excess brush, gangly cedar trees and young elms, the site for the dam became even more obvious. Mr. Swanson wanted to be able to see the lake from his house, which sits slightly uphill to the southwest of the site, three hundred yards away. Not only would he be able to see the lake, two gradually-sloping hills were perfectly in line to be the best targets to tie the dam together and keep that view intact.
With two bulldozers, a double-pan scraper, a trackhoe, sheepsfoot roller and backhoe on site, work commenced full bore. Otto even brought in some extra hands to be stick pickers when the time was right. Their job was to remove all roots, sticks and twigs where the dam was being built.
From an earthmoving standpoint, Job One was to remove all the topsoil from the dam site and set it aside for later use. Otto’s team then started excavating for the core trench, the keyway to minimize seepage through the dam. This fallow farm had been pushed to its maximum to produce crops so earlier era families could have an income. This earthmoving exercise showed some of the consequences, primarily several decades of layered erosion and lean topsoil.
Where the dam sits, two of those silty, eroded draws merged. Otto was concerned that years of erosion from mediocre farming practices would lead to several feet of gooey, pudding-like silt several feet under the surface, exactly where the core trench was to be built. However, due in some part to an extended drought, the material below ground level wasn’t too bad. There was a little moisture and the silted-in area of the eroded draw wasn’t so deep. The crew was able to remove the shallow silt and hit nice clay.
Otto always reserves a caveat for this part of the process. “I can’t usually tell a landowner what to expect when we build the core trench, mainly because we don’t know what lies beneath the surface of a creek or a draw. It could be eons of washed-in sand and gravel…or it could be like this one, very little.” Otto has horror stories about core trenches built 20 feet below natural ground level, just to get to soils that won’t seep so bad and that will support the weight of a big, heavy dam.
There were several other key components of building this lake. Yours truly convinced the landowner, Mr. Swanson, to keep the eroded gulley intact. It would make outstanding habitat for fish and create natural travel paths for the entire lake and its underwater inhabitants. That decision probably drove up cost of the dame some, since these nearby soils couldn’t be used to build the dam.
Since the entire run of the gulley was laced with young growth trees and brush, the decision was made to get rid of that stuff by hand, rather than heavy equipment. That meant men with chainsaws, brush piles and fire.
So, here’s the point where engineering, earthmoving and the process of building the dam meshed with the concept of designing the best fishing lake.
A dam is a structure, not unlike building a house. It needs to sit on a foundation, built methodically with the best material. Its job is to impound water and release excess water in an orderly fashion. A dam is stoic, standing guard faithfully every day of its life, protecting the lake, doing its job as designed. Designed and built properly, it doesn’t change.
The water which sits behind it though, is a different story. It’s a lake…a living, breathing entity that changes minute by minute, day by day. The way the lake bed is designed will determine its future. Since the goals are to add value to the property and provide enjoyment, recreation and fishing, we wanted to be sure the lake bottom was conducive to all those ideas.
That’s part of my job. We wanted to design spawning beds, nursery grounds for small fish, cover for young bass, the best habitat for big largemouth bass, too. We wanted to design and build areas for game fish to congregate where the anglers could catch them. The most thoughtful part was to use what nature provides to tie together an underwater community where all the inhabitants can thrive, for years to come. That’s a big reason we decided to leave that eroded gulley as it was.
We also wanted to avoid as much shallow water as possible. Shallow water is where excessive amounts of nuisance aquatic plants can grow. Too many plants spoil the mission and are a management headache.
There was an existing small pond sitting near the dam site. We wanted to keep most of it intact to offer structure for fish. Otto said, “It would have been cheaper to build the big dam if we could have pushed the old pond out and also dug into that creek. But, there were areas not far away that needed more depth and the clay was good. That’s why we brought in the scraper.”
As one part of the team worked on lake design, the drone of diesel engines and clacking of tracks kept us informed that dirt was moving and time was of the essence. We needed to step it up.
The core trench didn’t take long to excavate, maybe three days from start to finish. Otto called a meeting. “We need to get clay to start going up with the dam. I’m thinking we get it here on the west side and over there, on the east side.” He’d done his homework. That clay was near perfect for compaction to build a dam.
Lupe had set up a transit and we placed flags close to where the shoreline would be, all the way around the lake. That was important…extremely important…for us to design the interior of the lake. Knowing the shoreline helps us decide where and what depth to add all the elements of the fish habitat. It also showed Mr. Swanson the shape of his new lake-to-be.
He beamed like a proud father. The lake would be a perfect fit and excellent complement to his land. It would cover somewhere near ten acres. That’s large enough to enjoy and not so large to break the bank with management needs.
Here’s a little rule of thumb to understand. 90% of the fish live in 10% of the lake. But, that 10% tends to change with the seasons. So, my job as fisheries biologist is to think about fish behavior and design the best underwater community possible, based on the species of fish Mr. Swanson wants. Since the primary fisheries focus is on largemouth bass and bluegill, with some water dedicated to hybrid striped bass, our attention was zeroed in on providing the best elements and travel paths for different size classes of these different species of fish.
The dam was rising, fast.
Mr. Swanson decided he wanted a good percentage of the lake available for shoreline access for fishing, so the majority of the fish structure and cover was designed to be within casting distance of the shore.
There were several spots near the dam site where water would be less than four feet deep, so Otto’s team used the scraper to collect clay from there. Part of the lake design was to build some stair-stepped shelves from the shoreline downwards. Essentially, we accomplished two goals with this process. We got depth and shelves for fish. Otto got good clay for the dam. That’s good business of lake building.
As the dam rose, hand-cutting of brush and small trees continued. But, we were picky. We selected the best trees along the draw to save for fish structure. The rest were piled and burned. Nearing the end of the project, we cut the remaining trees and let them fall across the creek. Other trees and brush were dragged over to the shelves, where we built small piles, bringing the biggest logs perpendicular to shore. We also added washed river gravel in three different places where water was less than three feet deep, building spawning beds for bluegills and other sunfish.
Otto and his team installed an 8 inch PVC drain pipe with a valve. Anti-seep collars were added every 50 feet to keep water from escaping around the pipe. Otto is picky about installing a drain pipe. They brought in finely ground limestone to add to the existing clay and the soils are hand-packed tightly around the pipe, buried at least 18” and packed before he lets a bulldozer drive over it.
Construction took about six weeks, which is pretty fast.
As the project moved, Mr. Swanson saw things appearing that he wanted to make better. He saw one spot where he wanted a picnic area. It’s a flat zone adjacent to the upper end of the lake, where a few hardwood trees were preserved. The lake would be shaped like a left-handed check mark. At the inside tip of the check, he saw a perfect spot for a pavilion. Next to that should be a boat house. But, the shoreline there, with its 3:1 slope looked erodible to him. He decided to add limestone riprap.
It was during this stage of construction that Mr. Swanson was wrapping his brain around the different ideas how to use the lake. Better yet, Mrs. Swanson entered the fray. She had some ideas of her own. “Don’t we need a bathroom, if we have a pavilion?”
Of course you do.
Otto did his best to divert the attention so he could finish strong. “There’s a big enough area below the dam to build a small duck paddy.” Mr. Swanson bit. “Let’s do that, too.” Just so happens the valve will open perfectly to fill and flood a nice area to attract waterfowl during migration.
The spillway was directed to empty into the existing catfish pond, some 150 yards away. Good call, since that pond tends to drop when evaporation hits its summer peak.
With the dam completed, spillway finished, pipe in place and the lake bed nearing it finish line, we had the makings of a beautiful, appealing, fishy-looking lake.
In the third part of this three part series, we’ll show photos of the finished lake and the amenities Mr. Swanson added, as well as the fish stocking program.
Bob Lusk is a 35 year veteran private fisheries biologist and Lake Consultant, traveling the nation helping people design, build, stock and manage private fishing waters. He is also editor of Pond Boss magazine, the nation’s leading journal on pond management. He can be reached at [email protected].
Mike Otto has almost 40 years’ experience as a professional earthmover, with a primary focus building outstanding fishing lakes. He can be reached at [email protected]