SALEM, Ohio – Before you start making plans to dam up a stream for a livestock watering pond or a new fishing hole, you’d better run your idea past local and state conservation officials.
The Ohio Department of Natural Resources Division of Water is taking a more active role in pond construction throughout the state, but most landowners are not aware of current dam regulations, according to Owen Lenkner, district conservationist for Carroll Soil and Water Conservation District.
Three classes of dam-built ponds require building permits, he said.
“There’s a lot of complicated engineering involved in building a dam or pond, and a lot of people don’t pay attention to that,” Lenkner said.
“There’s much more to it than digging a hole,” he said.
The updated regulations went into effect in late 1999, but are often still violated, Lenkner said.
Designed for safety
Classification of dams is necessary for proper design and to ensure adequate safety according to the potential for downstream damage should the dam fail, according to the Division of Water. The classification is defined in the Ohio Revised Code Section 1501.
The state requires all dam builders to submit a preliminary design report to the state.
Dams under the division’s jurisdiction are divided into four classes during the preliminary design review or during periodic inspections.
Dams exempt from state authority include those less than 6 feet in height, regardless of total storage capacity; those less than 10 feet in height with not more than 50 acre-feet of storage; and those not more than 15 acre-feet of total storage, regardless of height.
Current state regulations require dams in Classes 1 through 3 to have permits prior to construction and to be designed by a certified engineer.
Whether or not your dam and pond need a permit, Lenkner recommends design by a certified engineer to ensure quality.
“If a person is willing to pay a contractor thousands of dollars for a pond, it’s probably also best to buy some peace of mind that it was done right,” he said.
“There are several things to take into consideration before you build a pond,” Lenkner said.
Some of the most important issues to consider include the amount of watershed feeding into the pond, height of the dam, soil type, and compaction.
Pipes to fill and empty ponds installed through dams are also of great importance. Pipe sizes are determined by watershed capacity, and require complicated engineering to function correctly, Lenkner said.
“If the pipes aren’t in there right, your pond will never fill, or will constantly overflow,” he said. Soil type is equally important.
“You’ve got to be sure to build a dam in the right type of soil, because if it’s too sandy, it’s going to wash away,” Lenkner said.
No more water
“I know of a contractor who built a dam and pond in an abandoned strip mine, and all the water ran straight out the bottom. A soil survey showed that the ground wasn’t appropriate, but it was too late,” Lenkner related.
If the site has too much silt in the soil composition, “it won’t bond and once it gets wet, it will turn to mush and ooze right out,” he said.
Some contractors mistake soil types and aid in creating dams destined to fail, Lenkner said. In order to curb this, several SWCD offices offer pond-building consultations and help with soil testing.
“I get one or two calls each week from people wanting a pond. I’m not a certified engineer so I can’t help design or build it, but I can look at the site and dig some test holes to see if the soil will hold water,” Lenkner said.
He also aids landowners in asking the correct questions to contractors so they can be involved in making decisions and hire the right company for the job.
Watershed size and location also needs to be understood prior to construction. As a general rule of thumb, each 6 acres of watershed will support a 1-acre pond.
A landowner needs to have enough water to support the pond, but also needs to consider the watershed source, Lenkner said.
“You’ve got to watch for contamination, like septic drainage or agricultural runoff,” he said. Phosphorus from both of those will cause an algae problem.
Erosion also creates other trouble, including decreasing depth and creating “muck” in the bottom of ponds.
“The main thing is to create as little disturbance to the watershed as possible,” Lenkner said.
For good reason
“I really hate to see people moving to the country get ripped off when they go to build their dream pond,” he said, noting that a soil report should be requested by potential land buyers before making their investment. He cautioned that not all land advertised as a “great possible pond location” lives up to its name.
For more information on dam regulations contact the Division of Water Dam Safety Engineering Program at 614-265-6731 or visit http://www.dnr.state.oh.us/odnr/water/.
For more information on constructing a pond or to get a list of certified engineers, contact your county SWCD office.
(You can contact Andrea Myers at 1-800-837-3419, ext. 22, or by e-mail at email@example.com.)
Dam and pond classification
- Dam and pond classification criteria include dam height, storage volume, and potential downstream hazard.
- Class 1 dams are those whose failure would result in loss of human life and severe structural and property damage. They also have a total storage volume greater than 5,000 acre-feet or a height greater than 60 feet.
- An acre-foot is equal to 326,000 gallons of water.
- Class 2 dams have a storage capacity of more than 500 acre-feet and do not exceed 40 feet in height. Dam failure would cause flood damage to homes, businesses or public facilities and wash-outs on roadways. Failure could also pose possible health hazards.
- Class 3 dams have a storage capacity of more than 50 acre-feet of water and a dam height of more than 25 feet. Failure of this type of dam would result in damage to low value non-residential structures, local roads and agricultural crops and livestock.
- Class 4 dams store less than or equal to 50 acre-feet of water and would create losses restricted mainly to the dam area. Dams in this category must be less than 25 feet in height.
- Most dams built to create ponds in rural Carroll County, and surrounding counties, fall into Class 4.