Re-Building the Bog on the “New Pond”


The finished bog viewed from the pond side.

The last pond that I built in 2010 I call the New Pond. It is over 6000 gallons and the largest one that I have. The first pond, built in 1990, is now relegated to the name of First Pond as it falls behind in size containing just 5000 gallons.

When I built the New Pond, I included a small bog on the side that was fed by it’s own supply from the main pump. It then returned the water back into the pond by gravity feed. I was pushed for room when I built it and it measured about 2 ft wide and 8 ft long with stacked stone walls on the three sides away from the main wall of the New Pond. I used the standard construction method which comprised of a liner and then filled with loose pea gravel. I planted it out with a mix of different plants and for the longest time, it worked well.

A couple of years ago, I noticed that the water level was dropping in the New Pond and went through the usual methods of trying to isolate where the leak could be. First, I shut off the pumps and the water still went down which told me that the leak was either in the pond or in the bog (or both). Suspecting that I had a rat chewing problem, I started a serious search from within the pond all the way around the water level and discovered an area of about 6 feet that the rats had chewed through the liner in several places from within the surrounding rocks which they had made their home. This resulted in me having to drain more water out of the pond to lower the water level and then to apply several glued on patches to the affected areas. The repair was simple enough and after giving it time to cure, I refilled the pond and started everything back up.


The finished bog viewed from outside the pond.

The water level held up for more than a year and then started to drop again. Suspecting more rats, I checked the repairs and they were still holding up so by a process of elimination, I isolated the bog area which turned out to be the culprit. With a lot of other things going on like Septic Tank Repairs, remodeling the bath to a shower and a host of other things, I just turned the bog off and let it grow out which it did with the most amazing display of Green Taro.

Having caught up with many of the other pressing things in my busy life, I turned my attention to this bog. Reluctantly, because of the Taro’s amazing growth, I dug out all of the plants, some in pots and others having already outgrown them with roots going everywhere. I saved the rhizomes for future use, transplanted what plants I could and then proceeded to dig out the gravel. I forgot to mention, that for once, the position of this bog with the gravel path running alongside of it, made it very easy to work on. As I removed the rocks that made up the exterior walls, I re-laid them into the new wall with very little effort so that I had the outline of the new bog. I was able to increase the size to about 3 ft average width and 12 feet long. I also planned to tear out the waterfall I had previously built and use the outlet from the bog to act as a return waterfall.

I dug out all of the dirt inside the new walled in area and cleaned everything up. I then completed most of the stonework bringing in other stone from a pile that I had elsewhere until the shape and depth were sufficient.

I was then faced with the problem of what to do inside the walls as in their current state, I could not cover them with a liner as the stones were so uneven. I got over the problem by building a 2 x 4 form which I filled with concrete. I used old wire mesh and used hardware cloth that I had laying around from another project for reinforcement to help hold it all together. When I finished the long wall, I worked alternately on each end wall so that the finished product was completely lined with concrete on the three sides. The side that surrounded the pond had enough existing dirt still from the original excavation that all I had to do was fill a few holes with concrete and smooth them over.

I measured the hole for the liner several times to make sure that I was allowing enough. As you pay for the liner by the square foot, it is very easy to want to skimp on it. I erred in the other direction having already made the mistake of having the liner a few inches too short on previous projects and having to make adjustments because of it. I visited Jeff Yarborough at <a href=”” target=”_blank”>Leaf Landscape Supply</a> to buy the liner as it is only a couple of miles from my house. Jeff is one of our Speakers and the company is one of the <a href=”″ target=”_blank”>Austin Pond Society Sponsors</a> so I like to give them my business. Not only that, I get a Club Discount which also made it worth while. As I usually do for this sort of thing, I drove out the back and helped one of the workers lay out the liner and then fold up the piece and put it in my trailer.

I needed some used carpet to put under the liner to give it a cushion and protect it from any sharp edges and made a couple of calls. Leaf Supply came through and suggested that I contact a Carpet installer off William Canon which I proceeded to do. They have this huge pile of used carpet outside and for a very small fee (they called it a donation for which I gave them $5), I could take all that I wanted. I got it home and installed it to completely cover the inside of the excavation.

Showing the carpet used as underlayment to line the bog.

Showing the carpet used as underlayment to line the bog.

On my previous efforts of handling large pieces of liner by myself, I had already figured out the best way to do it is to lay it out and then re-fold it in the way you want it to unfold. This save a lot of pulling and dragging and risking moving the rock walls or damaging the liner. It is much easier to move a liner in small lifts than to try to drag the entire thing. I’ll bet the piece that I had probably weighed a 100 pounds.

With the liner in place and folded the way I wanted it on the corners, the next step was to work on building the water chamber. This comprises of a space of about 8 inches between the floor and the medium that was going to hold up the larva rock which I was going to use as filter material. There are a variety of ways to create the space. Several of the Pond Society Members have acquired plastic Coke crates and stacked them end to end to fill up the space. I didn’t have a supply of these items but I did have an 8 x 4 feet sheet of small lattice plastic fencing material and several 8 x 16 concrete blocks. Prior to placing the blocks, I cut small pieces of liner to fit under each one so as to shield the liner and help to protect it. I placed enough of the blocks in such a way to support the lattice without any fear of it collapsing under the weight of the larva rock and then cut the lattice to shape. I used the entire sheet and prior to installing the lattice, I installed two 2 inch PVC pipes through which I had pre-drilled two rows of 1/2 inch holes about 6 inches apart. I threaded these pipes through the blocks so as to raise them off the bottom. I covered the whole thing with a layer of weed cloth of the absorbent kind that would allow the water to go through.

Having successfully gotten this far, I then filled the bottom up with water to allow the liner to settle into the corners before completing the rest of the work. The next part of the project was to hook up the plumbing which was a fairly easy job as the service to bring in the water from the pump was already in place. Using a tip learned from my previous work on the plumbing for the Septic System, I drilled a 1/4 inch hole below the water level in the upright feed pipe inside the bog to prevent an air lock as the pipes went from the ground, up and over the wall in the shape of an inverted U and back into the bog.

The next order of business was to purchase the larva rock. Previous experience had shown me that the bags at Lowe’s are 1 cubic foot compared to those at Home Depot which are only 1/2 a cubic foot for almost the same price. I purchased 14 of the bags. I was going to just put the rock into the bog loose but again, my friends warned me that it is tough to dig it out when the time comes to clean the bog and that I should use bags. With much more forethought and skillful planning than me, they had managed to buy used craw-fish bags from Louisiana at a fairly cheap price. I had to make do with laundry bags from Target which I paid a bit more for but mine are a little bigger and can contain more rock. Of course, that may also be a disadvantage as they may be too bloody heavy for me to get them out when the time comes. Given a few more years, and I doubt if I can lift what I do now. It’s hell growing old for many reasons.

I filled the bags and carefully installed them in the bog and filled in between with loose lava rock. The original plan was not to plant any pots or marginal plants in there but it looked so bare that I relented and stuck back in many of the same plants I had dug out of the previous bog. That was after re-potting them.

Before filling the bog with water, I checked to see that the outlet rock, a 2 x 1-1/2 foot slab was positioned and was level. It was very important for getting the proper waterfall effect, that this particular item be almost perfect. This rock, I had bedded in a mortar mix in order for it to be correct. I had already stacked rocks on the inside wall and used spray foam to fill the joints and prevent the water spilling out in the wrong places. I turned my attention back to the outside walls and completed placing the rocks to give it a finished look.

Then came the moment of truth.  I filled the water back into the bog and added de-chlorinator to prevent the new water from affecting the fish in the pond. As the water rose, I adjusted the liner in a couple of places and then watched as it reached the outlet stone and came out in a perfect waterfall. Breathing a huge sigh of relief, I watched for a while and then gave myself a mental pat on the back for another completed project.

It took me almost 2 weeks to complete this job and that was with long hours. Sometimes, I would run short of this or that and have to make a quick run to Lowe’s or Home Depot. Luckily, the weather for most of the time was pretty nice although it did get hot (for the time of year) for a couple of days.

The next projects are already in the works. This time, I have to explore why both streams are leaking. I have already re-built the Little Old Man stream 3 times with the last time of adding a concrete bottom and sides under the liner. As you have probably guessed, I have a rat problem in both of these areas too. For now though, as it raining fairly heavily outside, I am content to just write about the stuff already completed. Oh yeah, a big thank you to all of my friends for their words of wisdom. They helped me to stop from copying their mistakes.

Re-Building the Middle Pond.

The "L" shaped pond with the bog on the right.

The “L” shaped pond with the bog on the right just after it was built-in 2007.

My middle pond is kind of “L” shaped with the a bog on the inner side of the “L”. I had long viewed that bog as a source of irritation and was forever cussing out the guy that built it. As that guy happened to be me, all of the cussing and badmouthing in the world was going to have very little affect.

When I first built the pond, it seemed like a good idea to include a small bog. It never worked very well as there was not a sufficient flow of water to do anything more than to create at best, a marginal bog for those plants that like to have wet feet.

Needless to say, those plants which included Arum lilies, Lizards tail and a  few Rushes quickly grew out of their pots and sort of took over that part of the pond. Another thing that made me want to dig it out was that the Heron, in one of his many visits, uses the bog as his personal fishing spot, even with the electrified wires that I have stretched to prevent him (or her).

In a fit of madness, I dug out all of the plants and pots and cleared out all of the pea gravel that was chock full of roots and cleaned the whole thing down to the liner. It was at the very least, a dirty and smelly job but I persevered and got it done including removing all of the decorative rocks. Its funny but when I put the rocks down several years ago, they were not as half as heavy as they were this time around. Pretty sad how growing old is also a weakening factor. I looked at the resulting area and decided that I didn’t need the bog anymore and instead, would make the pond bigger by including the bog area.


View of the steps behind the tree leading to the new skimmer on the right.

In between working on the bog, I did a couple of fish rescues. At one of them, the owner wanted her goldfish removed as she didn’t want to care for them anymore but was still going to keep the pond. That was a straightforward job and I ended up with nine small goldfish that I placed in the middle pond. The second rescue was much more complicated as the lady in this one, wanted to fill in her pond and re-landscape the area. She not only wanted me to take the fish and plants but also to remove the skimmer and waterfall along with the pump. I could not pass up a chance like that and was more than willing to accommodate her. End result was 41 small Koi of assorted colors ranging from fingerlings to a couple at 6 inches and the aforementioned hardware and pond plants. She had one Umbrella plant which was the biggest I had ever seen and I really wanted it. Upon close examination, the plant had quite literally grown through the liner as it had expanded. I didn’t relish the work involved in rescuing the plant and left it behind.

As I surveyed the middle pond which now had close to sixty small fish in it, I envisioned installing the skimmer and the waterfall box and the difference it would make to that pond. The pond did not have a skimmer as it was originally a part of a two pond system and the skimmer was installed on the other pond. The problem I was facing was how to dig out enough dirt to make the pond bigger and deeper and still keep the fish alive and happy with about a couple of thousand gallons of water in it.

I thought about it for a while and then hit on the idea that I could roll the existing liner back enough for me to work on small sections at a time and still keep the water in the pond. I pumped the pond down to about 12 inches of water and I devised a way with 2 x 4’s of propping up the liner while I excavated underneath which I very carefully did, bit by bit. When I finished one section, I moved along and propped up more liner and on and on until eventually I had all of one side of the liner propped up. It was not done without incident as a couple of times, the 2 x 4’s slipped and I lost some water into the excavation which sent me scrambling to get the props back into place. It was not such a bad thing as it softened up the dirt a little. It was tough going anyway and any little bit helped. I gotta tell you that water is heavy stuff especially when it is contained in something as flexible as liner material.

I eventually finished the excavation to my satisfaction and then had the problem of lowering the liner back down into place. Needless to say, it did not go well and although it might have been possible with more help, I could not get a couple of the folds out of the liner as once I laid it flat with water on it, I could no longer move it. I couldn’t even pick it up anymore as I had done the first time around.

I had excavated a hole in one corner to install the skimmer and I must have measured ten times to make sure I had it at the correct elevation. There is an old carpenters saying of “measure twice and cut once” and I certainly followed the rule this time.. I finished off installing the skimmer as the last thing I had to do was to cut a hole in the liner and then screw the face-plate into place to hold it all together. Satisfied with my work, I back-filled around the skimmer box to keep it from moving and then re-arranged the rocks the way I wanted them.

Waterfall box from the back

Waterfall box from the back

The next part of the project was to install the waterfall box. This box was a big one, probably bigger than I needed but as I had it, I was going to install it. I had previously knocked down the existing waterfall that I had installed when I first built the pond. This composed of a small waterfall box surrounded by rocks that I cemented together. I forgot to mention that another reason for doing away with the bog and rebuilding the waterfall was because I had a slow leak and had narrowed it down to either of those areas. I didn’t find anything when I dug the old bog out but did notice a hole in the liner that was behind the old waterfall probably caused by rats which like to make their home in between the rocks that surround the ponds.

After installing the waterfall box, I was then faced with the task of re-working the plumbing to the different units. I was still going to include the 100 gallon Skippy Filter that was already installed and thought that it might be possible to pump directly into the Skippy and then let the water flow from it into the waterfall. It turns out that after I had hooked everything up, the 2 inch pipe from the Skippy to the waterfall box which was gravity fed, was not big enough to take the flow of water coming into the box. It didn’t matter how much I throttled it back, it was still too much water. So, back to the drawing board.

This time, I plumbed the skimmer/pump directly to the waterfall box and ran a detour pipe from that line into the Skippy. I then changed the Skippy outlet to a 4 inch pipe and ran it directly to the waterfall box. By using a couple of valves that I also installed on each line, I was able to control the flows to both the Skippy and the waterfall to where they are both working very comfortably. I also had to go down on the pump size from a 3500 gph to a 1200 gph which fixed the problem of too much force of water.

I re-arranged the rocks around the pond and the waterfall to my satisfaction and considered the main work done and refilled the pond. I finished the whole thing off with some plants around the Skippy tank and re-arranged the plants in the pond. I now have a very nice little pond that is so clear, you could drink it. The fish are getting to know me and are rushing over to the side when I walk up. That is not a good thing as they will probably do the same thing for any wayward heron that pays a visit. Having a lot of really big Koi that are more the 24 inches is nice but there is something to be said for the very small ones as at least they are active and rush around all over the place showing off their beautiful colors…

It’s Hot out There…while building a Skippy filter.

Finished Skippy Filter at work

Finished Skippy Filter at work

I got up early today with the view of getting outside and working a bit while it was cooler. That is, if you call 80 degrees cool as it quickly warms up here in my part of Texas. The overnight low was 74 and the forecast was for it to be at least a 100 degrees and could go as high as 104.
I had a couple of small projects that I wanted to get done. After the success of changing out the filter material in the big ponds and the small ponds filter systems to Lava Rock, I really wanted to do the same thing for the rest of the filters that I have located on the various ponds.
So, this morning I started out by building a new Skippy filter using a 20 gallon tub. I needed to do some work to it first like drill a hole and install the 2 inch drain system. I found a 2 inch fitting that reduced to 1 1/2 inch threaded fitting that had a flat area wide enough to take a rubber washer. I cut the washers (2) out of an old piece of liner material and placed both of them over the threaded end.  I followed up with a thin layer of Plumbers Putty and then placed it through the hole with the threaded area inside the tub. On the threaded area, I didn’t have a washer large enough to fit over the 1 1/2 inch screw fitting so I had to make do with a piece of hard plastic from a storage box that I had also cut out a 1 1/2 inch hole. I secured the whole thing with a threaded ring washer used on electrical conduit. It worked perfectly and after tightening the whole thing up I finished it by placing 2 inch Tee fitting set parallel to the pond level so that water could flow out both sides.
Showing outlet

Showing “T” outlet

In the bottom, I needed to make a water chamber so that the water would have a free flow as it came out before rising up through the lava rock to the drain. For this, I use 2 layers of plastic fluorescent light grid cut to shape and set up on 2 bricks, one either side of the pipe. The pipe itself is 2 inch and is set like an inverted Tee. On the ends of the Tee were 90 degree opposing elbows to create a flow of water. The center upright stands just above the rim of the tube and is eventually connected to the pipe from the pump. The theory is that the water comes in the top and then circulates from the bottom so that it comes through the Lava Rock and out the drain and back into the pond. The Lava Rock traps the dirt pretty efficiently. The 100 gallon one that I have installed on the big pond has really cleaned up that water. Incidentally, it works well to not glue the elbow situated on the top of the inverted Tee. This allows for easy removal of the grid when it is time to clean the unit. Otherwise, the center hole has to be pretty big to slide the grid over the screw coupling joint.
Close up of Lava Rock

Close up of Lava Rock

After completing the construction, with the final hook ups done in place, I filled it with 2 bags of the Lava Rock and then turned on the water to check that it worked properly. Satisfied with my work, I turned my attention to the old existing Skippy filter. I wanted to move it to a different location so that I could feed it with the main pump which is why I opted to build a new unit giving me more time to move the existing filter which is powered by a separate pump and contains the old filter material which I am replacing with the Lava Rock.
Close up of outlet drain

Close up of outlet drain

Moving it from its current location turned out to be easier than I had anticipated. Using mostly brute force and the judicious placing of a short 2 x 6, I moved it out onto the path and maneuvered it onto my dolly to be wheeled to the pond nursery area where I start all of the new pond plants. I will remove the Iris currently growing in it, clean it out and make any repairs that are needed and re-use it on one of the other ponds. With it gone, I was able to spend time on tightening up the electric fencing around that pond. I have fencing powered by a doggie shocker around all of my ponds to keep the Herons and Raccoons away from the very large Koi. You can see the fences in the pictures although they barely register with me as I am so used to them.

It is comparatively easy to hide the tubs either by stacking rock around them or using plantings of some of the taller Texas natives.
View of electric fencing

View of electric fencing

Now that I have a “spare” 20 gallon filter unit, I can take my time in preparing it to replace one or the other of the 2 existing ones that I have left, both of which have pretty extensive growths of Iris and Orange Canna. I may wait until the winter when the growth had died down before working on these two. As I pointed out above, the current “spare” unit also has a large growth of Iris in it which I need to dig out and re-plant somewhere or I might just give the Iris away. By the way, I do NOT plan on planting anything in the new filters. I would prefer they do not get enmeshed with roots even though the roots also act as a filter.
It took me all day to complete the project, I had to take a break and go to Home Depot for the fluorescent light grid as I was out of it but this only took about 30 minutes. Needless to say, my car would not drive past the Starbucks in Bee Cave so I had to humor it and buy a small latte. This tied me over until around 4:00 pm when I stopped for a tea break, but other than that, I was at it all the time. Funnily enough, even though it was a 100+ degrees, I never felt at any time that it was too hot to finish the project. I made sure I had plenty of water and I had liberally applied sun block and I was working in the shade for most of the time.
Must be getting used to the heat…..again.
 If you click on any of the pictures, they will enlarge and can be quickly changed by use of the side arrows. To get back to the blog, press the escape key.

Re-Potting Water Lily Plants 2015

Re-planting Water Lilies from Francis Allcorn on Vimeo.

This video was taken during the 2015 Willie Birge Memorial Pond cleanup at Zilker Botanical Gardens on March 14, 2015. People involved included Darren Bayhi as the lead man with volunteers from the Austin Pond Society, Jeannie Ferrier, Julienne Smith, Stephen Monfrini, Phil Prokaski, Charlie Melear, Chuck Graves and Bruce McDonald

Re-Potting Papyrus and Pickerel 2015

Planting Pickerel and Papyrus March 2015 from Francis Allcorn on Vimeo.

This technique applies to nearly all water plants.
This video was taken during the 2015 Willie Birge Memorial Pond cleanup at Zilker Botanical Gardens on March 14, 2015. People involved included Darren Bayhi as the lead man with volunteers from the Austin Pond Society, Jeannie Ferrier, Julienne Smith, Stephen Monfrini, Phil Prokaski, Charlie Melear, Chuck Graves and Bruce McDonald

Re-Potting Lotus Plants 2015

Repotting Lotus 2015 from Francis Allcorn on Vimeo.

This video was taken during the 2015 Willie Birge Memorial Pond cleanup at Zilker Botanical Gardens on March 14, 2015. People involved included Darren Bayhi as the lead man with volunteers from the Austin Pond Society, Jeannie Ferrier, Julienne Smith, Stephen Monfrini, Phil Prokaski, Charlie Melear, Chuck Graves and Bruce McDonald

%d bloggers like this: