STEP 1: MARKING THE AREA

First, determine the general area for the pond. Draw its perimeter with a hose, marking paint, or a stick. It is preferable to do that over time so you can make changes. While you are planning, remember this: Never build anything into the pond (such as rocks, trestles, viaducts, waterfalls, anything). Add them to the cement after it has cured. Why? Such additions expand and contract at a different rate than the concrete you will use for the pond. If they become part of the structure they could create a crack and a leak at some time, for example after an earthquake or a freeze.

When you have arrived at a final design, dig it to a depth of about four inches and look again to be sure you still like it. Let a week pass. Look at the area often, and make any corrections. When you are absolutely certain the design is perfect, plan a work party.

Invite everybody you can. Fire up the barbecue, provide plenty of cold drinks, and admit anybody with a shovel or a wheelbarrow. If possible, run a train somewhere nearby.

STEP 2: DIGGING THE POND

Eventually you will pour four inch thick concrete walls, so you must dig the pond four inches larger in every dimension to account for that. If you plan add rocks inside the completed pond, be sure to account for the space they will take up, too. And you must dig the edges at no more than a 45-degree angle or the concrete will be unable to adhere to the sides. It is important to slope the bottom toward the end where you install the drain and, of course, to determine the depth of the pond. If you want fish and plants, your pond may have to be deeper than if you want only water. Finally, if you want a waterfall, the pond should be deep enough at that point to provide a pleasing sound; you may have to include a depression or a pit somewhere on the pond bottom.

If you intend to include a waterfall, you will have to build a pad large enough to accommodate the waterfall, pump, filter, and electrical equipment. The pad is part of the pond. Its back must be higher than its lip, and its sides higher than its middle. That will allow any leakage from the equipment or the waterfall itself to drain into the pond.

Be sure you have done all that homework by the day of the work party. Also know exactly what your guests will do and be a good foreman. You must be there at all times to direct the progress and compliment your guests on their good work. They will appreciate your leadership. Also, choose between four and six of the best workers for future jobs; you'll need them.

I borrowed a transit and learned to use it so I could accurately determine the slope of the bottom of my pond. I also marked the waterline by pushing nails a foot apart into the earth, then running a string from nail to nail.

STEP 3: PLUMBING HARDWARE

The quantity of water circulating through the pond will determine the size of the pump, filter, and piping. If you plan to add a waterfall, you must figure the rise in feet to put the water over the fall and the gallons per minute necessary to create the effect. I took my design to a swimming pool contractor. He did the calculations for me in just a few minutes. He also suggested I install a swimming pool skimmer in my pond because I planted several large Japanese maples around it; they drop a lot of leaves.

Be sure to install an overflow pipe to send excess water where you want it.

Try to buy your pump and filter from a swimming pool contractor doing an upgrade. He should have several used pumps and filters perfectly satisfactory for your use. He may even give them to you at no charge if you promise to invite him over to run trains.

STEP 4: INSTALLING THE PIPES

I used 1 1/2 inch schedule 40 PVC for the drain and the skimmer. Whatever you use, dig a trench three inches deep and large enough to hold two pipes. Run it from the lowest spot in the pond to the back wall of the pond. Then dig a three inch deep trench into the back wall and run the pipes up the wall. We will eventually cover the trench with cement.

Now the pipe ends are at ground level. Fit 90-degree elbows to direct the pipes to the rear of the pad. Caution: Be sure to put each pipe in its own trench and spread the pipes in a V-shape so when they reach the rear of the pad they will be one foot apart. That will put them in the right spot for the plumbing we will install.

Fit a 90-degree angle to the end of the pipe where you plan to place the drain. Put a rag into the open end of the fitting to keep it clean.

Glue together the rest of the pipe (if necessary) and lay it in the trench so it extends one foot beyond the rear of the pad. Then glue the 90-degree angle over the drain, with the open end facing upward. Label the pipe "DRAIN" so you can identify it later.

Install the skimmer, if you use one, being careful to place the middle of the skimmer opening at the waterline. Read the directions carefully before installing it. I bought a piece of flexible PVC pipe from the swimming pool contractor. It makes the bend from the skimmer drain to the bottom of the pond easier to accomplish. Attach the flexible PVC to a pipe and run the pipe in the trench next to the drain pipe. Cut it one foot longer than the end of the pad. Label the pipe "SKIMMER" as you did the drain.

Note: If you make a depression or a pit below a future waterfall, you must provide a drain line from it when you install the other two pipes.

Fill the trench with soil and pack over the pipes on level areas.

Remove all excess and loose soil from the pond.

STEP 5: REINFORCING THE POOL

Buy enough 3/8-inch reinforcing rod to form a basket in the pond on one foot centers from waterline to waterline all the way around. If you plan to add a waterfall, the reinforcing rod must continue up the side of the pond where the waterfall will be to a point two inches above the top of the soil. Then bend it horizontal to the ground so it will be in the middle of the pad. You must also secure cross bracing on one foot centers as you did in the pond.

The rod is very easy to bend by hand. We used six inch wire bag ties (a wire with a loop on each end) and borrowed a tool (a Yankee Twister) to twist the ties together. They held together the reinforcing rods. The tool saved us about 80-percent of the time it would have taken to twist the ties with a pliers. If you are unable to borrow one, buy one. It costs 29 dollars.

Next place two inch dobees (square concrete blocks with tie wires sticking out of them) under the reinforcing rod wherever the reinforcing rods cross. Secure them to the steel. That will keep the reinforcing basket two inches above the soil and in the middle of the cement.

Buy a roll of 14 gauge 2 by 4 inch fence wire to place above the reinforcing rod. Tie it down with the bag ties. Cut the wire flush with the waterline or leave it a little longer and bend it over.

STEP 6: POURING THE CEMENT

At this point, you definitely want to avoid mistakes. I called the swimming pool contractor. He was really interested in the project and wanted to stop by for a look. He calculated how much cement I needed to build four inch thick walls for the pond and gave me the name of a cement finisher to help pour and finish the walls. Do not try to pour and finish the cement on your own unless you have plenty of experience, have the tools, and want to work very hard and fast. This is not the time to save money!

We ordered a seven sack mix with five pounds of black coloring per yard and asked the cement company to deliver it at the correct consistency to pour walls. Your finisher will add water to achieve a consistency he likes after the cement truck arrives. Tell the cement company exactly what you are doing; they know their product well and can tailor it to your needs if they understand them.

We also had the cement company arrange to pump the cement into the pond. It is worth the additional expense, particularly on a hot day when work must go fast.

My pond used 4 1/2 yards of cement. They poured it on a cool winter day. We used a finisher, his helper, myself, and a friend. That was enough manpower. On a hot summer day, you might need more help.

The next morning, we filled the pond with water to the overflow pipe by placing a hose in the top of the skimmer and letting the water flow gently out the door over the cement.

STATISTICS AND COSTS

The pond is L-shaped. The 26 foot leg is between 3 and 8 feet wide. The 8 foot leg is 4 feet wide. The pad for the plumbing and waterfall is 7 feet long and 4 feet wide. The pond is 12 inches deep. Here is the price list:

Reinforcing rod, 3/8-inch dia., 680 feet $95
Welded wire, 14 ga., 4 x 2 x 72" high, 1 roll, 50 feet long $35
Dobees, 2 x 2" with wire, 300 @ 20-cents ea. $60
Bag ties, 1000 ea. $11
Pipe and fittings $50
Swimming pool pump and filter (used) n/c
Swimming pool skimmer $55
Cement $357
Cement pumper $140
Cement finisher $100
Cement finisher's helper $64
Total: $967

Depending on where you live, materials and techniques may vary.