A trench, six inches wide and six inches deeper than the bottom of the pond, is dug around the boundary line. Keep the sides of the trench as vertical as possible, and its bottom quite flat. When the trench is done, call it a day so that the masonry work may be started early the next morning.

Since you have quite a lot of wall to do, mix up a good big batch of concrete. Use a 1-3-5 mixture (I cubic yard of cement to 3 cubic yards of sand to 5 cubic yards of gravel). When the dry ingredients have been thoroughly mixed (it will take at least two hours to do this) add about five gallons of water. This gives a good plastic mixture, not too stiff and not too wet. You can save yourself lots of time and work by ordering the concrete already mixed and delivered to you by your building supply house. It costs about $10 a cubic yard which makes it fairly expensive but sometimes circumstances (or your client) justify that additional expense.

Shovel some concrete into the bottom of the trench and trowel it out to a depth of two inches and a length of eight or ten feet.

Select the thickest rocks, wet them, and place them firmly on the concrete, setting them not more than an inch apart. Complete the first row of stones for the length of the wall along one side of the pond.

Now, trowel in another layer of concrete, making sure that it fills all crannies and nooks between the stones. This, and successive layers of concrete, should be about an inch thick. In setting in the second row of wet stones, place each one so that it is centered above the seam between the two stones underneath it. Gaps may be filled with smaller stones. Lay as many rows as is necessary to build the wall up to the level of the ground on the land side of the pond.

The top of the wall may be flush with the ground or built up above it an additional few inches. Since the top of the wall will be exposed to view, use the most colorful and flattest rocks for finishing it off.

The wall on the opposite side of the pond is constructed in the same way. When the top is reached, make absolutely sure that it is level with the top of the first wall. Several 2 x 4's, held together by means of cleats nailed on the sides, should be used as a testing beam. A carpenter's level is rested on the beam at the center. Test every foot or so and make necessary adjustments as top of wall is being finished off.

A layer of wet straw, grass or weeds should be laid along top of wall to keep it from drying out too rapidly. As you work on the dam take a few minutes off every now and then in which to dash pails of water along the sides of the wall. This aids the proper curing of the cement.