Ponds & Waterfalls – Layout & Excavation
First of all: know what you want. If you need some ideas, visit the library or your local book store and browse through landscape books, garden and pond magazines. You can also search the web and read and study as much as possible.
Layout is the most important phase of the entire project. I have heard many complaints from disappointed clients after they had a chance to get used to their new addition to the landscape. “I only wish we had made it bigger… made it deeper… added an island… made it longer and constructed a bridge… built it closer to the house… installed a larger water pump for the waterfall… or… built the waterfall higher or wider.”
Most of these wishes could have been granted for a reasonable cost before or during construction. But waiting until afterward means incurring a major expense that may be cost prohibitive. If your choice is to omit the item or feature because of its cost, then make structural preparations to allow for adding it on later. You can plan and design the landscape to allow for easy additions to the koi pond later just by the strategic placement of trees, sprinklers, drain lines, and much more.
When you decide exactly where you want to place the koi pond, take your time laying it out. A garden hose is popular for this job because it can easily be moved around until the desired shape is achieved. Once that is accomplished, you can use construction paint and spray the ground in the outline of the hose. If there is any doubt about where to locate the koi pond, give it a couple of days and ask for outside opinions. Then walk around the yard while you observe the proposed spot from various angles, especially views from inside your house, from the room where you spend most of your time.
Remember to take into consideration everything around it. How close is the nearest tree? Will its roots pose a problem later? Is there going to be sufficient sun throughout the day? Some water plants require more sun exposure than others, such as lilies. Make sure you know where the main power, water and sewer lines are routed to the house. It is not so good to find out after the fact that the gas or water line runs right through the center, 36 inches below the surface of a 48 inch deep koi pond.
Do not land-lock a section of your yard that may later need drains, sprinklers or heavy construction material. Place in advance or remove such items and install necessary drains and sprinklers. If it is not convenient to run the sprinklers at this time, run 4 inch drainpipe sleeves under the stream or section of pond to enable running low voltage wire and sprinkler lines later.
When it comes to the koi pond depth, if you plan to have it more than 18″ deep, you will need to check with the local building codes to determine if a 6 foot perimeter fence is required. You may also need door alarms and self-closing gates at the side of the house. If the koi pond site is not level, do not worry about it; you will have all the excavated dirt from the pond to level out uneven terrain and get creative with terracing for an upper koi pond and waterfall or a sloped portion of the yard for a stream or creek.
A pond can be placed on the side of a hill by constructing a retaining wall to hold back portions of the hill. Drive a stake in the ground until the top of it represents the water surface of the koi pond. Continue with additional stakes in the shape of the pond builders proposed pond using a level as you go. Keep in mind how deep the koi pond should be and begin to remove the dirt. As you do so, note the condition of the soil and determine if you will need only shovels and a pick, or if you will have to rent a jackhammer. Also, if the soil is sandy and unstable, you may need to shore up the sides with plywood forms and supports prior to pouring concrete.
Most often the soil from a pond excavation can be used to create berms in the landscape plus mounding for a waterfall. If the koi pond is large the excavated dirt can be used to terrace a level back yard, facilitating a second, elevated koi pond. If there is no access to the back yard for a bobcat or excavator, additional soil will need to be removed by wheelbarrow and can be dumped into a rented trash bin or dumpster.
The most important stage of the water feature project is planning, not layout and excavation. If you have not planned and predesigned your waterfall and koi pond by now, file this article away until you do.
First of all: know what you want. If you need some ideas, visit the library or your local book store and browse through landscape books, garden and pond magazines. You can also search the web and read and study as much as possible. Layout is the most important phase of the entire project. I have…