We have a vast variety of landscapes here in Ohio due in part mostly to the glaciers. About two-thirds of Ohio was covered by glaciers at least once in history. As the glaciers moved slowly across our state, it shaved off hilltops and deposited soil and stone in very many different ways.
As they melted several natural waterways and ponds were left behind. Since that time, several man-made bodies of water have been constructed for many different purposes. Most of these projects have been successful, but some have not. If you are ever thinking about wanting to add a pond to your own landscape there are several variables to consider.
Pond factors
The first thing to consider is size of the proposed pond. Generally speaking, an acre pond needs at least 10-15 acres to be able to sustain through the wettest and driest times of the year.
A pond with a watershed too large may have excessive inflow during heavy rain events that leads to sedimentation and cause water quality issues. Also, the pond needs to be able allow water to exit in such a manner that outlet structures, dams and spillways are not washed out during storms. Conversely, the watershed must be big enough to maintain water levels during drought periods. Ideally, a pond should be designed so the water level doesn’t fluctuate more than two feet during the dry months of the year.
Depth issue
Along with surface size of the pond, one must consider depth. For most, a depth of 8-10 feet is ideal for the aquatic life of ponds around this area. In the most northern reaches, it may be necessary to be deeper to accommodate the colder winters, but depths of more than 12 feet are usually wasted excavation dollars. Depths deeper than that really don’t benefit the fish population.
The deepest portion of the pond need only be about 25 percent of the total pond area for total aquatic life production. However, large areas of water that are only 3 feet and less will most likely be overcome with algae and vegetation. So, constructing your pond with a 3:1 slope to the proposed depth offers the easiest management and the best aquatic life benefit.
Location
With size, depth, maintenance and purpose, the next thing to consider is location. The topography of your land will play a big part of location and design.
Types of ponds
Basically, there are three types of ponds: excavated, embankment and combination.
The excavated pond is where soil is removed in a generally flat area where no dam is needed. In more sloping terrain it may be necessary to build a dam in between two hillsides to collect surface runoff. Most times it is a combo of excavating and a dam that is used to create the correct slope and depth of water impoundment. No matter what design is used, the least amount of disturbance is desirable from a cost and eco-friendly standpoint.
Once a landowner figures out the size and location of the proposed pond with regards to the proper watershed, the most critical piece of information needs to be investigated. Test holes to look at the underlying soil are necessary to see if it is conducive to hold water and have the bearing strength for proper construction. A site investigation can be set up with your local Soil and Water, along with an ODNR Soil Scientist, to determine the feasibility of pond construction.
The landowner is asked to have a means of excavating test holes to 2 feet deeper than the ponds proposed depth. The investigation of the soils is a free service to county residents. The time and money of the excavator is a small investment to ensure success of the pond. Pond construction can be expensive so it highly recommended to use your resources prior to machines moving soil.
There are several other factors to consider prior to building a pond. I encourage you contact to your local Soil and Water to set up a site visit to discuss them as well as the above topics.
A successful pond can be very rewarding and enjoyable, but a failing pond is a very costly and frustrating issue. Proper planning produces a pleasurable pond . . . now say that one three times fast!
