Did You Know… Basic Pond Construction, Part 1 of 4

— Written By and last updated by Pam Brylowe

As we move into spring, many land owners begin to consider what it would take to develop their own sport-fishing ponds. Of course, there’s a bit more to it than just “digging a hole in the ground”. Today’s article is the first in a 4 part series on basic construction considerations when building the typical watershed pond.

Water supplies Watershed ponds are usually filled by surface runoff from an area above the dam. This area, the watershed, can be estimated by drawing a line on a topographic map that follows the ridge lines forming the perimeter of the watershed (Fig. 1). The watershed area and pond acreage can be roughly estimated using a planimeter. Field engineers with the Natural Resources Conservation Service (NRCS) should be able to help landowners with this calculation.

Figure 1
Figure 1

The entire watershed area of a proposed pond must be investigated to determine whether runoff might be polluted. Large chicken and hog farms, extensive areas of row crops, grazing live- stock, industrial sites and other water quality hazards in the watershed could preclude the operation of a watershed pond. Good watersheds contain well-established, undisturbed vegetative cover such as timber or grass. A buffer zone of grass or sod should surround the pond, especially if there are croplands, concentrated feed lots, or large denuded areas in the watershed.

Springs or streams can be used as a water source. Large streams flowing through watersheds may require some kind of diversion device. Streams can be contaminated with wild fish or man- made pollutants, so it’s a good idea to get the water tested before construction begins. Also, large inflows of soft water in acid soils may hinder any long-term remedial effects of liming.

When choosing a pond site, consider the soil type, topography, characteristics of the watershed and, of course, safety. A power supply for aeration equipment should also be available to power pumps, aerators and the like, if needed.

The suitability of a pond site is mostly dependent on whether the soil will hold water when compacted by heavy machinery during the construction process. Soil composition ranges from pure sand to heavy clay. Soil type can vary drastically within a single site. The pond area should contain a relatively impervious layer of clay or silty clay soils. Coarse soils containing large amounts of sand and/or gravel are unsuitable. If the soil can be formed into a tight ball that maintains its shape or is moldable, it is suitable for pond construction. A rule of thumb is that soil must contain at least 20 percent clay.

If there is poor soil over a portion of the pond, large amounts of clay may have to be trucked in to make it impervious, and that could make construction costs too high. Also beware of limestone areas. They may have sinkholes or caverns just beneath the surface. Ponds built in limestone areas have been known to drain completely overnight!

The type of soil in the dam area is especially critical for safety reasons. Dam seepage can lead to dangerous dam failures. The NRCS and some private agricultural and civil engineers have hydraulic probes that can sample soils several feet down. A backhoe swipe also will help in analyzing soil. Cutoff trenches and dam cores must be located where soil has a high clay content so they will remain structurally sound during the life of the pond.

The objective is to locate a pond where the largest storage volume is obtained with the least amount of earth fill needed for the dam. Locating a dam between two gently sloped ridges in front of a broad section of valley is ideal. The less pond excavation needed, the more feasible the site and the lower the construction costs.

Information for today’s article was published as “Fact Sheet No. 102, Watershed Fish Production Ponds: Guide to Site Selection and Construction”, by the Southern Regional Aquaculture Center. The entire article can be located online at: http://srac.tamu.edu. For additional information, please contact Mike Frinsko, Area Aquaculture Agent, Jones County Center at: 252.448.9621 or mike_frinsko@ncsu.edu

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status, or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

As we move into spring, many land owners begin to consider what it would take to develop their own sport-fishing ponds. Of course, there’s a bit more to it than just “digging a hole in the ground”. Today’s article is the first in a 3 part series on basic construction considerations when building the typical watershed pond.

Water supplies Watershed ponds are usually filled by surface runoff from an area above the dam. This area, the watershed, can be estimated by drawing a line on a topographic map that follows the ridge lines forming the perimeter of the watershed (Fig. 1). The watershed area and pond acreage can be roughly estimated using a planimeter. Field engineers with the Natural Resources Conservation Service (NRCS) should be able to help landowners with this calculation.

The entire watershed area of a proposed pond must be investigated to determine whether runoff might be polluted. Large chicken and hog farms, extensive areas of row crops, grazing live- stock, industrial sites and other water quality hazards in the watershed could preclude the operation of a watershed pond. Good watersheds contain well-established, undisturbed vegetative cover such as timber or grass. A buffer zone of grass or sod should surround the pond, especially if there are croplands, concentrated feed lots, or large denuded areas in the watershed.

Springs or streams can be used as a water source. Large streams flowing through watersheds may require some kind of diversion device. Streams can be contaminated with wild fish or man- made pollutants, so it’s a good idea to get the water tested before construction begins. Also, large inflows of soft water in acid soils may hinder any long-term remedial effects of liming.

When choosing a pond site, consider the soil type, topography, characteristics of the watershed and, of course, safety. A power supply for aeration equipment should also be available to power pumps, aerators and the like, if needed.

The suitability of a pond site is mostly dependent on whether the soil will hold water when compacted by heavy machinery during the construction process. Soil composition ranges from pure sand to heavy clay. Soil type can vary drastically within a single site. The pond area should contain a relatively impervious layer of clay or silty clay soils. Coarse soils containing large amounts of sand and/or gravel are unsuitable. If the soil can be formed into a tight ball that maintains its shape or is moldable, it is suitable for pond construction. A rule of thumb is that soil must contain at least 20 percent clay.

If there is poor soil over a portion of the pond, large amounts of clay may have to be trucked in to make it impervious, and that could make construction costs too high. Also beware of limestone areas. They may have sinkholes or caverns just beneath the surface. Ponds built in limestone areas have been known to drain completely overnight!

The type of soil in the dam area is especially critical for safety reasons. Dam seepage can lead to dangerous dam failures. The NRCS and some private agricultural and civil engineers have hydraulic probes that can sample soils several feet down. A backhoe swipe also will help in analyzing soil. Cutoff trenches and dam cores must be located where soil has a high clay content so they will remain structurally sound during the life of the pond.

The objective is to locate a pond where the largest storage volume is obtained with the least amount of earth fill needed for the dam. Locating a dam between two gently sloped ridges in front of a broad section of valley is ideal. The less pond excavation needed, the more feasible the site and the lower the construction costs.

Information for today’s article was published as “Fact Sheet No. 102, Watershed Fish Production Ponds: Guide to Site Selection and Construction”, by the Southern Regional Aquaculture Center. The entire article can be located online at: http://srac.tamu.edu. For additional information, please contact Mike Frinsko, Area Aquaculture Agent, Jones County Center at: 252.448.9621 or mike_frinsko@ncsu.edu

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status, or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

This article was published in the Jones Post newspaper on March 7, 2013 and was compiled by Mike Frinsko, Area Commerical Aquaculture Agent.

Written By

Photo of Mike FrinskoMike FrinskoArea Specialized Agent, Agriculture - Aquaculture Serves 18 CountiesBased out of Jones County(252) 448-9621 mike_frinsko@ncsu.eduJones County, North Carolina
Updated on Apr 5, 2013
Was the information on this page helpful? Yes check No close
This page can also be accessed from: go.ncsu.edu/readext?205003