Pond Rebuild – Bulkhead

When we moved into the house in 2015 one of the first yard projects was to dig a pond. This served two purposes, the first being the aesthetics of having our own private pond to enjoy and the other is that it supplied a lot of dirt for building up low areas of the property.

Pond drained for servicing

With a 60 foot diameter the pond was calculated to be about 25,000 gallons.  For a water source I had an artesian well installed, this is a deep well that has natural pressure and is pretty commonly used in Florida for irrigation. This well provided enough pressure for a fountain and helped maintain the water level of the pond since there was continuous loss through ground seepage and evaporation. The loss was pretty minimal but the fountain also provided aeration to help support the fish. Neighbors supplied Tilapia, Brim, and Bass from their ponds and by the end of 2015 we were in business.

Fast forward to early 2017 just as spring was arriving and heating up the water. I  went out one morning and saw a few dead fish floating up. By the end of the next day there were several hundred floaters with no signs of life in the pond. I spent the day cleaning up and trying to figure out what went wrong and after discussions with several people the most likely cause was oxygen starvation. The water level had dropped pretty low (I would manually add water when we were in a dry spell), the water was warming up causing organic matter to start breaking down, plus there probably wasn’t enough aeration to begin with (well water may have little or no dissolved oxygen).

This was a good time to implement a few ideas I had been thinking about. I would dig the pond deeper to help keep it cooler plus add more water volume for the fish, add additional aeration, and figure some way to keep the water level constant. A big part of the solution was to add a remote sump, that would allow me to add these additional features without a bunch of ugly pipes and pumps exposed near the pond.

Pond sump drawing

I’d add a second pipe to the sump area to run additional wires and hoses for things like the fountain and aerator hose. With a plan in place, it was time to get down to business. The easy part was digging the pond deeper which also provided more fill dirt to use around the yard. The next step was to build a concrete bulkhead, this is where the pipes for the sump and accessories would enter into the pond. Previously I had just run a pipe straight into the pond but that was ugly, may as well do it better this time.

Forming a bulkhead from scratch seemed pretty complicated so I just started with a concrete block cut down. I found a bunch of 2 1/2 inch electrical conduit on clearance at the local Home Depot so that would be the size used, otherwise I would have gone with 3 inch. To get started with the concrete I just placed the pipes face down on a piece of plywood (with their appropriate ends attached and taped up to protect them).

Setting up pond bulkhead pipes

I made them slightly different lengths so the connections wouldn’t be exactly lined up, it also served as a reminder to keep checking which I am working with later since they serve different purposes. Here’s another shot of the setup:

Pond bulkhead pipes pre-concrete

Once the concrete was poured and hardened, I built a form for the front part to give it a slope and a lip on the bottom. The purpose of the lip is so I can fan off any debris that gets there without worrying about undermining the bulkhead (protects the dirt underneath). No scientific method went into the angle as the bank slope varies. 45 degree seemed good enough and it ended up working well.

Pond bulkhead formed up

During the concrete pour I inserted some wire to add strength. Note I tried to build the form to be easily disassembled after the concrete set, that didn’t quite work as designed so some of it had to be cut to be removed.

Pond bulkhead form poured

The result after removing the form:

Pond DIY bulkhead

It came out very nice and strong after letting it cure for a few days. A view of the back:

Back of pond bulkhead

One last thing to mention, the connectors are different on the pond facing part of the bulkhead. One of the openings is threaded, that is so I can connect a pipe or hose so when filling the pond so the water doesn’t just flow right out of the opening. If it did, it could cause erosion or undermining of the bulkhead. Instead, I’ve made a distribution pipe that can be screwed in to spread the water out, much like a sprinkler. The other connection is not threaded since it is just for accessory lines.

Completed pond bulkhead

The next step for the pond was to build, plumb, and install the sump along with the bulkhead, these will be the topics of the next few posts.

Happy planting!