It’s pond time

Don’t tell Sandy… but the real reason I wanted a new house wasn’t because I wanted a shorter commute, or to be near biking paths, or have more of a community feel, or to be near a walkable downtown, or to have more nature around, or to have more space… the real reason is I needed a bigger yard to build a pond.

I began working on my plan… Sandy checked out lots of books from the local library on building ponds… I took lots of measurements and spent hours on the computer working up detailed designs.  Working out the size and shape of the pond, placement of the waterfall box, and exactly what the rate of drop should be for the stream.
But in the end, Tim came over and we just kinda winged it… building the retaining wall for the waterfall hill took two days.  First we calculated how long each 6×6 inch timber would need to be for the 4 foot tall retaining wall.  Then we went to home depot to pick up the timbers… very heavy… took two trips to get them all home.  Now it was time to cut… to be extra cautious we used the rule of thumb, “measure twice, cut once”, to make sure we didn’t make any mistakes.
Unfortunately, we should have used the rule of thumb, “trust but verify” and had Tim check my original math regarding the length of the timbers.  We were supposed to have nice, consistently spaced steps… but I was off with trying to figure out the lengths and the steps were not very even.  The problem is that in the corner, where the two walls meet, we wanted to interlock the timbers.  This meant that every other timber had to stick out another 5 inches (because 6 inch timbers are actually only 5 inches – the wonders of capitalist math).  So instead of steadily decreasing the length of each timber by 8 inches as we went up the wall, we had to alternate between decreasing the length by 13 inches and 3 inches.  Or something like that…. apparently I didn’t quite get it, because after a while we realized we weren’t getting the even stepped look that we wanted.
After scribbling lots more numbers on paper, we figured out how to recover from the miscalculations and after a couple of hours all of the cuts had been made.
Of course if we just stacked the timbers and said we were done with it… it wouldn’t take much to knock the wall down.  We needed something to hold the wall together.  Our plan was to get pieces of rebar, drill holes through the timbers.
Day 2 involved stacking the timbers and drilling holes for the rebar.  We had a number of 4 foot pieces of rebar (and a few shorter pieces) that we would use to drive through the stack of timbers and hold everything together.  We used my dad’s old hammer drill… a relic of an earlier age… it’s cord was dry rotting in places but it was able to do the job.  The rebar was 1/2″ diameter.  We used a 3/4″ drill bit so that the holes weren’t too snug.  On prior projects we used a 1/2″ drill bit and then had to use a sledge hammer to really pound the rebar into the holes.  It was a real pain in the @ss… especially if you made a mistake and had to pry the timbers back apart.  I was afraid a 3/4″ bit would make the holes too big, but Tim thought it would be okay and in the end he was right… as he always is
We started by stacking all of the timbers and then drilling down from above.  Our drill bit was a foot long so we could get through a couple of timbers at a time.  Once we’d drilled all the holes for one layer, we’d remove that layer of timbers and use  the holes that had started in the next layer of timbers as guides to continue drilling down.  Well… as it turned out, not all of our holes were straight and by the time we’d gotten down to the fourth or fifth layer some of the holes were coming out the back of the wall.  Fortunately, we were driving enough rebar through this wall that a few misses wouldn’t matter in the long run.
By the end of day two, we had our retaining wall complete.
this picture shows the completed retaining wall, the hoses outlining the pond shape, and I sketched in the stream path and waterfall placement.