The photos on the right (slide show) show the early stages of my pond design and excavation. The area chosen was previously excavated to install wood retaining walls. While this made digging the holes a lot easier, it has come back to haunt me. The dirt was not sufficiently packed when it was replaced (not my fault!) and so the entire pond has been sinking under the weight of rocks and water. I didn't expect this to happen and only left enough liner to tuck under the rocks.
Now the edge of the liner is within inches of the water level and likely by spring will not support turning on the pumps and waterfalls without it spilling over the edge.
So what's my plan?
In the spring, I intend to enlarge the pond to make more room for the large Koi that I keep there (small when I bought them but boy do they grow!) This obviously will involve replacing the liner with a larger sheet. I am thinking about installing a wood frame (pressure treated) around the outside of the pond to help keep the rock work from sinking. My thoughts are that a rigid frame would provide enough surface area and rigidity to keep the rocks from sinking.
Everything is always easier said than done, especially when it comes to moving large volumes of dirt. Since I have two pond, I can work on one at a time. If I run into issues and have to put off something then I wont have Koi in small swimming pools all over the yard...or worse yet in the bath tub (I'm sure that would go over well with my wife and family).
Right now it's very cold in the water, about 37 degrees and the fish are hibernating for the winter. All pumps are turned off and all filters have been drained. Last night a skim of ice formed on the surface. I use two floating pond heaters to keep a hole melted in the ice. You don't need to heat the entire pond. The hole allows toxic gases to escape and provides some meager amount of oxygen to be absorbed by the water. They are 100watt type and are connected to a thermo-cube, a small electrical device that turns the heaters on at an air temperature of 35 degrees and off when the air temp gets back up to 40 degrees. This saves a bundle on the winter electric bill.
There is no feeding until the pond gets back up to about 60 or 65 degrees in the spring and they are fed only wheat germ type food until the water temp gets above 70 degrees.
As we get closer to the spring thaw, I will post the details of the pond remodeling here.