Pond Construction Project, Phase 1

Here is a photo documentary phase 1 of my pond project, which is just the basic rectangular pond.  Phase 2 will involve adding a 4'W x 5'D x 2'H refugium with a viewing glass atop one end of the pond, and phase 3 will be a raceway along the back lip, again with front viewing glass.  This whole thing started a few years back when I was working at Home Depot.  I scored a nice piece of 45mil EDPM pond liner, 12' x 29',  for about 12 dollars.  This was the end of a roll which had been discontinued and buried back behind some other stuff.  The the question was, what to do with it?  I found the idea of digging a pond that size really daunting.  Plus, I hate digging.  Then, I had to worry about neighborhood dogs getting into it and stuff.  So, for several years, the liner sat in my workshop collecting spider webs while I tackled other projects.  BUT, the idea was never forgotten.  I eventually decided that, since I do like working with wood, I would build the pond above the ground rather than in it.  I figured landscape timbers would look nice, and I calculated the materials cost to be around $300 - not bad at all.  After kicking around some dimensions, I decided on 20'L x 5'W x 3'H.  During actual construction I decided to stop at crotch height so I could easily get in and out of the pond.  It is still almost 3' high, but the actual water depth is more like 2.5', which is still plenty.  Plus, as you will see from the last photo, the sides were already flexing a good bit.  I calculate the water volume at 1566 gallons (inside dimensions).

 

The Site

This is where I decided to build the pond. The dog kennels are on the other side of the fence. We raise standard poodles (these are large dogs, not the little heel-nippers you're thinking of), which were originally bred to be water retrievers. They absolutely LOVE getting into water, so it was necessary to separate the two. In the background is my workshop that I built about 5 years ago.

Site Preparation

The site was not level (is it ever?), so after raking away all the sticks and debris, I marked the construction area with string and leveled the string with a line level. Then I set landscape timbers in a bed of sand level with the strings. These timbers were not used as the base of the pond, but merely served as guides for screeding a level sand bed, which would support the base timbers and liner. You can see where I piled up sand to be used for the bed. I had a good sand pile left from another project, and after finishing the pond I still have enough left for something else.

Leveling the Site

Here you can see how I used the timbers as guides for a screeding board, which is how I got the sand bed perfectly level.

Fully Prepped Building Site

And here it is, all smooth and ready to build on. This part of the project took an entire day, as you can see by the long shadows. In the background my wife is hosing out the puppy run. The screen porch you see on the back of my house serves as a puppy kennel, and I built it especially for that purpose. From the outside it looks just like a nice little porch - which it is, most of the time!

Laying the Foundation

Getting the first row of landscape timbers positioned properly was the hard part. The only nails I used were on the very top rail - all the timbers were held in place by rebar, which I drove into the ground for added stability. I used 28 pieces of 3/8" x 4' rebar for the pond. One advantage of overlapping the timbers the way I did was that the sides were self-straightening, and (I thought) more than suficiently rigid. Plus, if the pond turned out not to be level, I could slide the timbers (well, actually it's a lot harder than it sounds) up or down the rebar posts as necessary. Fortunately, my prep work paid off and the final water level was even to within 1/2 inch along the entire perimeter of the pond.

Marking Jig

This project would have involved a LOT of measuring and marking, all using repetitive measurements. I had to mark where the holes for the rebar would be drilled, plus where the timbers had to be cut. I saved a LOT of time by making this marking jig. Here you see a nail which I used to mark the drill spots. The jig has little holes drilled in it just where I need them, so all I had to do is tap a nail in the hole and pull it back out. The nail head left an impression on the wood underneath, which is where I drilled the hole for the rebar.

Marking Jig, pt. 2

And here you see one way I used the jig to cut timbers to length. The side of the jig not only held is in the proper position against the timbers, but stuck out just enough so I could mark where I had to make cuts at the corners (every other row had to have the width of one landscape timber taken off at each end). The entire length of the jig was sized for the short sides, and I had alignment holes for the other two lengths I would need to cut. I didn't use a measuring tape the whole time!

The Finished Form

Here is the basic form, ready for the liner. At this point I drove all the rebar into the ground, level with the top of the form.

Lizard's Eye View

Since there's no liner or water in it yet, I can't call it a fish's eye view, can I? I didn't feel too bad about the footprints in the sand, since after I had done all that screeding and leveling, my cats discovered The World's Largest Litterbox, and made liberal use thereof. Plus there were various animal tracks in it the next day. Most of my land is "natural" and I live in the country, so a lot of critters pass through during the night. The tracks you see here are of the bipedal sort.

Filling the Pond

Here's the liner in place. I used newspaper between the liner and the landscape timbers as I wasn't sure the liner wouldn't try to squeeze out between the timbers. Plus, the butted ends didn't line up perfectly due to different lumber dimensions, and I was afraid of punctures at these points. That's a lot of newspaper, but we had a lot left over from our last litter.

Phase 1 Completed

Here's the finished pond with the top rail installed. I couldn't add the rail until the pond was filled because I needed to trim the liner after it had settled in. The rail is made of 2x8 lumber, and an adult can comfortably sit or walk on it. It can also be used for flowerpots :-)

Curvature Due to Water Pressure

I'm glad I didn't make the pond any longer or deeper, as the sides were not as rigid as I thought they would be. As you can see, the horizontal deflection is about 6" in the middle of the pond. I cut the miters and butt joints of the top rail to accomodate this curvature, so that they would be nice and tight. Now all I need is some fish to put in it! As I write this it is October 2005 - I don't plan on planting until next Spring. The pond is situated so that it gets about 1/2 day of direct sunlight.