a guide to

C R E A T I N G

V E R N A L 

P O N D S

all the information you need to 

build and maintain an ephemeral wetland

• • • • • • • • Thomas R. Biebighauser • • • • • • • • • •
My wife Dee gave me a great deal of support and kind words about writing this book. She did 

not mind when I was out late with contractors building wetlands all summer and fall. My 

parents helped my interest in wetlands grow into a life-long ambition when they drove me all over 

Minnesota back roads to check muskrat and beaver traps. I thank Dave Manner, my supervisor, for 

supporting the establishment of so many wetlands on the Morehead Ranger District of the Daniel 

Boone National Forest. Forest Service co-workers Richard Hunter, Frank Bodkin, George Morrison, 

and Melissa Eldridge helped me build hundreds of wetlands and patiently listened to me expound on 

their value for years. I thank Earl J., Billy and Don Osborne for sharing their tremendous knowledge of 

pond construction techniques with me during numerous wetland construction contracts. Frank Bodkin 

patiently helped prepare many of the photos and drawings you see in the book. Cynthia Moore from 

Ducks Unlimited skillfully completed the design and layout for this publication. The following individuals 

provided technical information about using explosives to to make ephemeral wetlands: retired USDA 

Forest Service Certified Blaster Paul Tine’; USDA Forest Service Certified Blaster Jon Hakala; and 

Brandywine Explosives Vice President of Operations Thomas McMahan. I especially thank USDA Forest 

Service Taking Wing Program Coordinator Cindy Ragland for encouraging me to write this book, for 

her many excellent suggestions, and for making publication possible.

The following individuals reviewed and provided comments on the draft book: Mark Bailey, 

Conservation Service Southeast; Jeff Briggler, Missouri Department of Conservation; Erin Clark, 

Savannah River Ecology Laboratory; Ernesto Garcia, USDA Forest Service, J. Whitfield Gibbons, 

University of Georgia; David Hoge, USDA Forest Service; John Jensen, Georgia Department of 

Natural Resources; Leo Kenney, Reading Memorial High School; Bruce A. Kingsbury, Indiana-Purdue 

University; Russell LaFayette, USDA Forest Service; Kevin Leftwich, USDA Forest Service; Gary 

McElroy, USDA Forest Service; Thomas E. Moorman, Ducks Unlimited, Inc.; Wayne Owen, USDA 

Forest Service; Gwyn Rowland, Izaak Walton League of America; and Melvin L. Warren, Jr., USDA 

Forest Service. Jane Singleton, retired USDA Forest Service, and Gwen Hensley, USDA Forest Service, 

edited the final draft of this book.

• • • • • • • • • • Acknowledgements • • • • • • • • • •

Thomas R. Biebighauser

All photographs in this book are by the author unless noted.

Copies of this publication are available from: USDA Forest Service, 2375 KY Highway 801 South, 

Morehead, KY 40351. Phone (606) 784-6428.

Cover photo shows the aquatic plant sweet flag surrounding a vernal pond constructed in Menifee 

County, Kentucky, 5 years ago.

Published by the USDA Forest Service in cooperation with 

Ducks Unlimited,Inc. and the Izaak Walton League of America.

USDA is an equal opportunity provider and employer.
T

om Biebighauser works as a wildlife biologist for the USDA Forest Service on the Morehead 

Ranger District of the Daniel Boone National Forest in Kentucky. He began making wetlands 

in 1982 on the Superior National Forest in Minnesota. He moved to Kentucky in 1988 and has 

since established over 700 seasonal, permanent, emergent, and forested wetlands in Kentucky 

and Ohio. He built these wetlands in partnership with numerous organizations and thousands 

of volunteers. Tom received a National Forest System Taking Wing Award for completing the 

Wild Wings Wetland Project 

in 1993, a Taking Wing Award 

for Leadership in Wetland 

Restoration in 1998, and 

a Taking Wing Award for 

Community Involvement in 

2001. In 1999, he was the 

recipient of the Award of 

Merit sponsored by Goodyear 

and the National Association 

of Conservation Districts for 

outstanding accomplishments 

in resource conservation 

practices. 

About the Author • • • • • • • • • • • • • • • • • • • •

Melting snow fills a constructed vernal pond. About this Guide

• • • • • • • • • a •

T

he techniques described in this publication have been used successfully in Kentucky, 

Ohio, and Minnesota. They draw from basic pond building principles and are coupled 

with the concepts of vernal pond ecology. The full geographic application of this guide is 

undetermined, however it is anticipated that the techniques offered are suitable for vernal 

pond construction in the eastern, southern, and mid-western United States. This guide is 

designed to help the reader think through site selection and the construction process in 

creating a vernal pond that looks and functions like a natural wetland. 

This guide stresses the importance of maintaining and protecting natural wetlands. It also 

provides the reader with clues for identifying wetlands during the dry season. The techniques 

provided in this guide may be used by a variety of individuals from the suburban homeowner 

to the educator, the public land steward, and the private landowner. It is the intent of this 

guide to assist and inspire individuals to select an appropriate location and to successfully 

build a vernal pond in their area.

1
Table of Contents • • • • • • • • • • • • • • • • • • • •

Chapter 1: About Vernal Ponds pg. 3 

A vanishing feature

Habitat for common and uncommon wildlife

Watershed protection

Education

Mosquitoes

Chapter 2: Planning A Vernal 

 Pond Construction Project pg. 6 

Who can make a vernal pond?

Are permits needed?

Know what to expect

Know the area

Look for construction fill

Avoid natural wetlands

Cost considerations

The surrounding landscape

Staying away from conflicts

The wet-dry cycle

Water depth

Soil permeability

Watershed size

Shade versus sunlight 

Water table

Test the soil

Design your vernal pond

Protect your investment

To plant or not to plant

Woody material

Chapter 3: Constructing A Vernal Pond pg. 17 

Choosing a construction method

Key to construction methods

Dozer method

 Remove and save the topsoil

 Make a core under the dam

 Build the dam

 Make a spillway

 Install Drainpipe

 Finishing touches

Track-hoe and dozer method

Liner method

 Use a quality liner

 Protect the liner

 Cover the liner with soil

 Using hand tools to install a liner

Plastic tubs

Clay liners

High water table sites

Track-hoe method

Blasting method

Maintenance

Chapter 4: Reference Material pg. 32 

Sources of information

Vernal pond construction, supply, and

 budget needs

2
V

ernal ponds are a type of seasonal or temporary 

wetland. They were once common, naturally 

occurring features on the landscape. The scouring 

process resulting from the ebb and flow of flooding 

rivers, lakes, and oceans created many vernal ponds. 

Others developed through wind action, earthquakes, 

falling trees, fire, and chemical actions in the soil. 

In most cases they are shallow, temporary, and 

separated from streams and rivers. This often made 

them tempting candidates for draining or filling. By 

nature of their ability to hold water, many were 

deepened and are now managed as permanent ponds 

and lakes. 

Vernal ponds are known by many names and vary 

in definition. In some locations their name denotes 

the relationship to the vernal or spring equinox. In 

areas where the seasons are less pronounced, many 

refer to them as ephemeral, seasonal, or temporary 

wetlands. Regardless of the name, the defining 

characteristics are that they periodically dry up and 

do not contain fish. Drying may occur annually or 

only in drought years. In general they dry most 

often in late summer or early fall; however, heavy 

rains may fill them any time of year.

In recent years society has begun to appreciate the 

ecology of vernal ponds and seasonal wetlands. It is 

the temporary aspect of these wetlands that makes 

them so important. The wet-dry cycle prevents fish 

from becoming established, allowing critical breeding 

and rearing habitat for amphibians, crustaceans, and 

insects. Vernal ponds and other seasonal wetlands 

provide a window of necessity for these species to 

function and fulfill their role in the ecosystem.

Another characteristic of vernal ponds is that the 

soil on the bottom is often quite firm. Periodic 

drying allows leaves and dead plants that have 

accumulated in the wetland to decompose, making it 

much easier to walk in than a wetland that contains 

water all year. There may also be indicator aquatic 

plants such as cattails, bulrushes, and sedges that 

thrive in their static or non-flowing water. 4

chapter one • • • • • • • • • • About Vernal Ponds

Seasonal wetlands are important for the 

survival of certain dragonfly species. 

Two-year-old vernal pond in fall.

Two-year-old vernal pond in winter.

Two-year-old vernal pond in spring.

3
For a variety of reasons vernal ponds are not as common as they once were and the possibility of restoring 

them in the exact location where they once occurred may be limited in most areas. Their temporary nature 

has not provided them the consistent legal protection often afforded permanent water wetlands. Many natural 

vernal pond wetlands have been claimed by society and are now covered by expensive infrastructure such 

as roads, buildings, and parking lots. Fortunately, we can re-establish vernal ponds that look and function like 

their natural counterparts. By applying basic site selection skills, we can place these new wetlands in the same 

general area that they once occurred, restoring an important component of the landscape. 

Incentives to restore or establish seasonal wetlands are plentiful - to prevent flooding by holding rainwater; 

to have a place to wade with the tadpoles, or to hear the melody of spring peepers and the chorus frogs on 

a spring night. Replacing this vanishing part of our landscape is as rewarding to us as it is essential to the 

health of the environment. 

4

a vanishing feature

Many amphibians such as this spotted salamander 

depend on seasonal wetlands.

The federally endangered Indiana bat, along with 

nine other bat species, use vernal ponds located on 

ridge tops in eastern Kentucky. (John MacGregor 

photo)

habitat for common & uncommon wildlife

Waterfowl such as the wood duck and mallard 

use vernal ponds extensively during migration, 

consuming insects, crustaceans, and seeds for 

energy during their long flights. Shorebirds, such 

as the spotted sandpiper and lesser yellowlegs, 

search out and feed on exposed mud flats that are 

created as water levels drop. Reptiles such as the 

eastern box turtle and the eastern garter snake 

also use vernal ponds, often as feeding stations as 

they move from one area to another. Mammals use 

vernal ponds too. Bats are attracted to them as a 

water source and to the insects that fly over the 

water.

Wetlands that do not contain fish are uncommon. In 

North America, approximately one-half of all frogs and 

one-third of all salamander species rely on seasonal 

or temporary wetlands for development. Wood frog, 

spotted salamander, and eastern spadefoot toad larvae 

are just a few of the amphibians that can successfully 

mature and emerge from these fishless habitats. Vernal 

ponds are less likely than permanent water ponds to 

contain saprolegnia, a fungus that is detrimental to 

frog, toad, and salamander eggs. Vernal ponds also have 

low numbers of eastern newts that prey heavily on 

amphibian eggs and larvae.
5

Mosquito larvae may be found 

in vernal ponds, developing from 

eggs to adults in less than a week 

in warm weather. Salamander, 

dragonfly, and damselfly larvae, along 

with many predatory insects such as 

the water strider and backswimmer, 

eat mosquito larvae. Dragonflies 

and swallows patrol the daytime 

sky over vernal ponds, preying heavily 

on adult mosquitoes. Bats frequent 

the night sky over vernal ponds, also 

feeding on mosquitoes and other flying 

insects. One rarely encounters adult 

mosquitoes near vernal ponds in 

eastern Kentucky; their numbers are 

kept in check by all the species that 

use them for food. 

A vernal pond makes an excellent 

outdoor classroom, offering learning 

experiences from design and 

construction to full restoration 

phase. Vernal ponds are generally 

easily accessed, allowing students to 

collect eggs and tadpoles from frogs, 

toads, and salamanders. An evening 

visit often produces a rich chorus 

of frog and toad calls, providing 

opportunities for sound identification 

studies. Several curriculums may be 

established around the development 

of a vernal pond, allowing students to 

track plant and animal life in different 

seasons. A list of teaching aids is 

found in Chapter 4.

Vernal ponds help protect watersheds. They capture and hold water, allowing time for it to seep into the 

surface and recharge groundwater supplies. This reduces the amount of water runoff, lessening erosion and 

downstream flooding. Vernal ponds also capture sediment, thereby protecting water quality in streams and 

rivers.

One scoop with a dip net may yield dragonfly larvae, 

daphnia, water boatmen, and isopods. (Evelyn Morgan photo)

Visiting a vernal pond can be an exciting environmental 

education field trip.

watershed protection

education

mosquitoes
6

Vernal ponds can be designed to fit into land parcels 

of most any size. They can make a positive addition to 

a school, visitor center, office complex, or your home 

landscape.

One need not be an engineer or biologist to make a 

vernal pond. However, depending on your experience, you 

may want to consult a professional. Professional wildlife 

managers have been establishing and restoring seasonal 

wetlands for many years and can be an excellent reference 

for the novice. 

A variety of techniques may be used to create a vernal pond. 

The complexity of this work often depends on the site and 

the desired size of the pond. The techniques range from hand 

tools, to blasting, to heavy equipment. Your familiarity and 

comfort in working with these techniques should guide you in determining if you want to do the work yourself or 

seek professional advice and service. Programs may be available that provide technical and financial assistance for 

constructing a vernal pond. You may want to contact a wildlife biologist employed by your state fish and wildlife 

agency or a district conservationist with the USDA Natural Resource Conservation Service for assistance.

chapter two • • • • • • • • • • Planning a Vernal Pond Construction Project

who can make a vernal pond?

This small vernal pond was built at the edge of 

the Prestonsburg Elementary School playground 

in Kentucky.

A thirty-year-old constructed vernal pond. A natural vernal pond in Morgan County, 

Kentucky.

R

egardless of the project, planning is always a critical step. Chapter 2 will lead you through the basic principles 

of understanding a local environment, its functions, and how those functions affect vernal pond construction. 

With an eye to basic landforms you should be able to make a vernal pond that looks and functions like a natural 

wetland. 

Many vernal pond constructions are successful; however, a few fail to meet expectations. Generally, projects 

fail because the ponds do not hold water long enough for aquatic plants to become established and for aquatic 

animal larvae to completely develop. Building a pond that fails to hold water is generally due to permeable 

soils, a poorly constructed core under the dam, and failure to compact soil during construction. This chapter is 

designed to help you think through site selection, to introduce you to construction techniques, and to help you 

determine the best location for constructing a vernal pond. 4
Some communities require that you obtain a 

permit before constructing a wetland. The permit 

process may be designed to help insure that 

habitat for federally endangered and threatened 

and state rare species is not impacted by a 

project. The U.S. Army Corps of Engineers and 

state agencies may require a permit before you 

build a vernal pond in an area that is already a 

wetland. Permits may also be required if you 

plan to construct a dam in the floodplain of a 

stream or river. Vernal pond projects may fall 

under a general nationwide permit or a waiver 

may be granted from permitting agencies. It is 

recommended that you look into permitting 

requirements for your area in advance and obtain 

all necessary permits before starting a vernal pond 

construction project.

This four-year-old vernal pond contains a diversity of 

plants.

are permits needed?

know what to expect

It will take time for plants to become established 

in and around this four-month-old vernal pond.

Contact electric, gas, water, and phone companies 

to identify possible buried utilities on the location. 

This is especially important when digging near 

roads and schools and other buildings.

One must modify the landscape to make a vernal 

pond. The extent of modification depends largely 

on site selection and the desired size of the pond. 

Sometimes constructing a vernal pond may involve 

moving a considerable amount of soil. In those 

cases, heavy equipment such as a dozer or trackhoe may be the most efficient means to shape the 

new wetland. 

Some people find the use of heavy equipment 

and the appearance of exposed soil unsightly and 

troublesome. Depending on climate, it often 

takes constructed wetlands about five years to 

“heal” and to develop a natural appearance. The 

most obvious concern is exposed soil that does 

not establish plants immediately. This can be 

unsightly, as well as an erosion concern. Seeding 

annual species such as wheat and applying straw 

for mulch can stop erosion and give a new 

wetland an attractive appearance.

This track-hoe is being used to make an ephemeral 

wetland. These machines are also used to drain 

natural wetlands.

7
8

Existing vernal ponds are difficult to identify during the dry season. Often a low, wet place will look like a 

good location to establish a new vernal pond. These locations should be carefully examined to make sure 

that they are not existing natural wetlands. Some clues that may alert you to the presence of a seasonally dry 

wetland include: dark stained leaves, caddis fly larvae cases, fingernail clams, aquatic snails, bright green sedges, 

and a lack of trees growing in the depression. These natural wetlands are most likely already providing habitat 

to many plants and animals. 

know the area

look for construction fill

avoid natural wetlands

Dark stained leaves in an area with few trees often 

indicates an existing vernal pond during the dry phase. 

This field may once have been a wetland, considering the 

present drainage ditch. The area could be made into a 

wetland today.

The importance of protecting 

natural wetlands cannot be over 

emphasized. One should use care 

when selecting a location for a 

vernal pond so that habitat for 

federally endangered, threatened 

and state rare species is not 

adversely affected. Consider asking 

a biologist for help in selecting a 

suitable location. a

The opportunity to restore a vernal pond at the exact location where one once occurred is limited in most 

areas. However, it may be possible to return vernal ponds to the same region where they once occurred. 

Old aerial photographs can help identify the location of natural wetlands that once occurred in an area. More 

recent aerial photographs can help identify wetter areas that may be suitable for vernal pond construction. 

Talking to landowners and people who manage the land can yield valuable information about the size and 

shape of historic natural wetlands in your 

area. In general, it is easier and less expensive 

to create a vernal pond in an area that has 

soils that can be made to hold water without 

using a synthetic liner.

When near developments such as buildings 

and roads, one may encounter low areas 

that have been filled with waste rock, gravel, 

concrete, asphalt, stumps, and logs. This 

mixture of construction debris is quite 

permeable, making it difficult to construct a 

wetland unless a synthetic liner is used. Use 

a shovel, post-hole digger, or a backhoe to 

test the soil for the presence of construction 

fill prior to building a wetland.
9

Other considerations in deciding where to build a vernal 

pond should include the long-term management and 

maintenance of the completed wetland. Avoid placing vernal 

ponds in areas where human and animal disturbance cannot 

be controlled. Excessive use by horses and cattle will damage 

and destroy vegetation, puncture synthetic liners, trample 

amphibian eggs, and disturb wildlife. Well-intentioned humans 

may also stock fish in vernal ponds, rendering them unsuitable 

for many species. 

A vernal pond is a living ecosystem that is constantly changing 

and evolving. The pond you know today may look and function 

differently in 5 years. A vernal pond can fill up with sediment 

in only a few years if the surrounding landscape is bare soil, or may last for hundreds of years if surrounded by 

vegetation.

Vernal pond built on a closed road.

cost considerations

the surrounding landscape

staying away from conflicts

Natural and constructed wetlands are often 

temptations for ATV riders.

There may also be human-made features on the landscape that are functioning as vernal ponds. Motor vehicle 

tire ruts often provide the shape and compaction needed to make small, linear wetlands. Consider retaining 

these small wetlands in roads that are no longer driven. 

A disadvantage of a road rut wetland is that it becomes a 

deathtrap for amphibians when a vehicle drives through it 

during the breeding season.

Water bars used to stop erosion on roads may also 

become vernal ponds. A water bar is a small dam 

placed across a road to slow flowing water. Most water 

bars are made so that they do not trap runoff, but 

divert the water in small amounts to the side of the 

road. Placing a shallow dip in front of a water bar can 

make a small vernal pond that also helps trap sediment. 

Most natural vernal ponds occur on level areas. Building a vernal pond on level ground is easier and less 

expensive than building one on a hillside. An area with less than 3 percent slope (3-foot -change in elevation 

over 100 foot length) works best for construction. 

If large trees are present, a small wetland may be located between the trees. It is possible to make a vernal 

pond in a tree gap as small as 15- by-15-feet with hand tools and a synthetic liner. Removing large trees from a 

wetland construction site is difficult and costly, and in general, not recommended. 

Cost estimates for a variety of construction methods can be found in Chapter 4 - Reference Material. 

A greater variety and number of species can be expected to use a vernal pond if it is built near other 

wetlands. Nearby wetlands provide a source of amphibians, reptiles, insects, and plants that can readily 

colonize a new vernal pond. A mosaic of wetlands best meets the habitat needs of species such as shorebirds 

and waterfowl. However, a variety of species will use a wetland that is built in most any location. Even 

isolated wetlands are known to provide habitat to rare species. 
The following factors and their relationship to each other influence how often a pond dries up:

4 Water depth 4 Annual precipitation and evaporation 4 Soil permeability 4 Watershed size (amount of water that runs into the wetland from surrounding land) 4 

 Amount of sunlight 4 Transpiration from trees, shrubs, and plants growing in and around the wetland

Key to constructing a successful vernal pond is that it not only holds water but also dries up once in awhile. 

In general, 90 or more consecutive days of water are needed over the winter and spring to allow insect and 

amphibian larvae to develop. A shallow wetland with a limited watershed in a sunny location is likely to dry 

up every year and may not provide enough time for salamander and frog larvae to develop. However, a deep 

wetland with a large watershed in a shaded location may never go dry.

10

the wet-dry cycle

water depth

The same vernal pond at various stages of drying - - May and October

This small wetland may never go dry; it is deep and 

surrounded by trees.

The factor that you can influence most is water 

depth. Making a pond too deep produces a wetland 

that holds water all year. One of the best ways to 

determine how deep to make a vernal pond is to 

examine other wetlands in the area. The best time 

to do this is in the fall or driest time of the year. 

Look to see if these wetlands have a small or large 

watershed. Identify if they are in the sun or shade 

and if the soil type is comparable to your area. 

If these characteristics are similar to the area you 

are considering for a vernal pond, then you have 

a good point of reference. Look for water lines 

along the shore and measure how far the water 

level dropped from spring. This can provide you 

with a good idea of how much evaporation to 

expect in an area. 
Fine textured soil such as clay and silt loam holds water for a long time. Coarse textured soils such as sand 

and gravel allow water to seep into the ground, greatly reducing the amount of time a vernal pond made from 

these soils would contain water.

11

soil permeability

Rainfall averages 49 inches a year in eastern 

Kentucky. Wetlands 20 inches deep or less 

in sunlit areas or 15 inches deep or less in 

shaded areas with no watershed dry up most 

every fall. a

Constructed vernal pond on 

the Daniel Boone National Forest

in the process of drying.

the kentucky experience

Prepared by and available from Douglas Norgord, Geographic Techniques, 

203 W. Garfield Street, Mount Horeb, WI 53572-2126

Greater than 180.00

140.00-180.00

100.00-140.00

80.00-100.00

70.00-80.00

60.00-70.00

50.00-60.00

40.00-50.00

35.00-40.00

30.00-35.00

25.00-30.00

20.00-25.00

15.00-20.00

10.00-15.00

7.50-10.00

Less than 7.50

Precipitation (inches)

Information on average annual precipitation in your area may be obtained 

from the USDA Natural Resource Conservation Service: 

http://nationalatlas.gov/prismm.html. Personnel at your local USDA 

Natural Resource Conservation office may also have information on precipitation and evaporation rates for your area.
Unlike farm ponds, a large watershed is not necessary for a vernal pond. The vernal pond with many acres 

of water running into it may never go dry. A large amount of water entering a vernal pond with a large 

watershed may damage the vernal pond and prematurely fill it with sediment. Vernal ponds can be successfully built in areas with no watershed, filling with water just like a birdbath in your backyard.

12

shade versus sunlight

S U N N Y

Greater diversity in aquatic plants.

Attractive to birds such as redwing blackbirds and 

common yellowthroat warblers for nesting.

Cattails may grow so densely that they crowd out 

more desirable plants.

Water warms earlier in the spring, promoting rapid 

development of amphibian larvae.

S H A D E

Aquatic plant diversity will be much lower.

Less likely to dry up annually compared to those 

exposed to sunlight. 

May contain uncommon grass and sedge species 

adapted to shady wetlands.

Falling or windblown leaves provide a rich 

environment for invertebrates, creating a food source 

for salamanders.

watershed size

Vernal pond in full sunlight. Shaded vernal pond with limited aquatic vegetation.

Should a vernal pond be located in the shade or sunlight? Finding a site that provides both sunlight and 

shade allows maximum benefits; however, finding such a location may need to be balanced with other considerations such as soil permeability and watershed size. Following are factors to take into account when 

choosing between sunny and shaded locations.
13

Most vernal ponds are built on sites that do not have high water tables. High water table sites are 

uncommon in many areas. A way to test for a high water table is to dig a test hole down below the topsoil 

layer. Topsoil is dark colored and full of roots. A high water table is present when the hole fills with water 

seeping in from surrounding soil. If water seeps into the hole, you should wait to see if it rises near the 

surface. Some areas may have a seasonally high water table. Building on a site with a seasonally high water 

table results in a wetland that holds water during wet periods. The soil on a site with a seasonally high water 

table is generally quite permeable. Checking the elevation of water in the soil during different times of the 

year will provide a better idea of when the wetland would contain water. Personnel at your local USDA 

Natural Resource Conservation Service office may help you complete a soil test.

Look for crayfish burrows on the surface 

of the site being examined. If crayfish 

burrows are present, see if water is near 

the top of the burrow. Burrowing crayfish 

dig down into the ground until they 

reach water. A lack of water in a crayfish 

burrow indicates that a permeable soil 

layer is found deeper in the ground. A 

wetland built on such a site may not hold 

water without using a synthetic liner or 

the specialized construction techniques 

described in Chapter 3.

A site with a high water table may 

already be a wetland. Federal and state 

laws protect existing wetlands in many 

areas. Permits from both federal and 

state agencies are often required before 

you may be allowed to alter an existing 

wetland. Contact the U.S. Army Corp 

of Engineers and the appropriate state 

agency before making an ephemeral 

wetland on a site with saturated soils.

test the soil

water table

A crayfish burrow that contains water near the surface 

is an indicator of a high water table.

It is important to test the soil texture at the location where you would like to build a vernal pond. The 

best way to do this is to dig a test hole. A shovel, soil probe, post-hole digger, or backhoe may be used 

to dig a test hole. It is important that you dig several holes in the area and that they are deep enough to 

display the soil profile. It is best to test the soil at a variety of depths. Try to test soil texture to a depth 

of at least 4 feet. If you find that you are working in an area with silt loam or clay soils, you can make a 

vernal pond at a reasonable price; other soil textures will require mitigation and increased cost. 

Use your hand to determine if the soil is clay or silt loam by attempting to make a two-inch long ribbon 

between your thumb and forefinger. You may need to add water to the soil sample to form a ribbon. If 

you can make a ribbon of soil at least two inches long, the site should hold water. The fine soil particles 

will keep water from leaking out of the wetland.
Look at the surface of the soil. Gravel indicates 

that the site is too porous to hold water. One 

cannot make a 2-inch long ribbon by squeezing 

gravel or sand between a thumb and forefinger, 

even if water is added to the soil sample. If you 

have no other choice than a site with sand or 

gravel, you may be able to use a liner to build a 

successful vernal pond.

One of the most troublesome circumstances 

involving soil properties and vernal pond 

construction is when you have silt loam on top 

of gravel. Gravel presents serious problems 

in making a pond, even when 8 feet below the 

surface. Ponds built where silt loam occurs on 

top of gravel will not hold water without special 

attention to the core. Information provided in 

Chapter 3 explains how to mitigate this problem, 

but it is important that you know before 

construction. One way to determine if silt loam 

exists on top of gravel is to look at a stream bank 

below the construction site. Look for an area 

where the soil is exposed on a vertical creek 

bank. The soil layers in the stream bank most 

likely represent those at the construction site. 

If the bottom of the creek is gravel you should 

test the soil on the potential wetland site with a 

backhoe.

14

Stream bank with silt loam on top of gravel. 

designing your vernal pond

the kentucky experience

Natural vernal ponds located on ridge tops in 

eastern Kentucky average 60 feet in diameter 

(0.06 acres). In riparian areas in that same region 

the presence of drainage ditches and drain tiles 

indicates that much larger wetlands, over 3 acres 

in size, once occurred. a

A 0.6-acre vernal pond on the 

Daniel Boone National Forest.

Forming a ribbon indicates silt loam or clay 

texture soil that should allow a site to hold water. 

You can make a vernal pond in a variety of sizes and shapes. Consider making the pond’s edge irregular, 

round, or oval to help it blend into the natural surroundings. Natural wetlands have gradual slopes leading up 

to the water’s edge. These gradual slopes are important to the emigration of fully developed amphibian larvae 

and, as the wetland dries, the mud exposed along the water’s edge provides feeding sites to many shorebirds. 
15

Using a level to measure slope on a 

vernal pond construction site.

This contour map shows a 4-foot-change in elevation 

over the construction site.

protect your investment

Mulching exposed soil with straw can help stop erosion 

and promote plant growth. 

4 Feet

Stream

3 Feet

2 Feet

Dam

4 Feet

3 Feet

2 Feet

Stream 1 Foot

A 3-foot-high dam will flood most of the area.

You will need to make a dam that traps runoff 

for the ephemeral wetland unless your site is 

level. The location and height of the dam can 

be marked with stakes or plastic wire flags. The 

maximum height of the dam is usually equal to 

the difference in elevation between the highest 

and lowest place on the construction site. The 

dam on an ephemeral wetland generally ranges 

from 1-to 3-feet high. The dam is placed along 

the lower edge of the project site.

You may want to use a hand-held or tripodmounted survey level to measure slope on the 

construction site if it is larger than 0.25 acres in 

size.

Make a sketch of where you want to construct 

the vernal pond and mark the pond outline 

on the ground with flags, chalk, or stakes. Drive 

a nail in a tree or set a stake in the ground at 

an elevation the same as the desired top of the 

dam. This benchmark will serve as a valuable 

reference during construction. Enlisting the help 

of someone with survey experience can help you 

design larger vernal ponds.

1 Foot

To reduce erosion seed and mulch the exposed 

soil above the elevation of the water level in 

the new vernal pond. Winter wheat or annual 

rye provides excellent protection from erosion. 

These plants often germinate within three days 

of seeding and fortunately, are non-invasive. They 

live for less than a year; during that time, natural 

plants should colonize the area.
16

to plant or not to plant

the kentucky experience

Research completed on the Daniel 

Boone National Forest by April Haight 

found that over 50 species of aquatic 

plants grew naturally in constructed 

vernal ponds within 5 years of establishment without planting. a

These aquatic plants grew naturally in 

a constructed vernal pond

A variety of species were planted in this constructed 

vernal pond.

The log these students are placing in a vernal 

pond will be used by turtles for basking and the 

green heron for hunting.

woody material 

Natural vernal ponds located in forested areas often 

contain branches and logs. Placing branches and logs in 

and along the shore of a created vernal pond will greatly 

increase the number of wildlife species that use the 

new environment. Salamanders such as the spotted and 

Jefferson’s will attach their eggs to tree branches that 

have fallen into the water. The marbled salamander lays 

its eggs beneath a log or under leaf litter in an ephemeral 

wetland during the fall when it is dry. The autumn 

rains help hatch the eggs, giving them a head start over 

other breeding amphibians. Emerging salamanders find 

protective cover in the logs near wetlands as they wait 

for suitable conditions to migrate from the water to the 

forest. 

Native terrestrial or aquatic plants may be 

planted in and around a new ephemeral wetland 

if desired. The Internet may be used to identify 

one of the numerous nurseries that specialize in 

the sale of wetland plants across the nation. A lot 

of money can be spent purchasing aquatic plants 

with uncertain results. Aquatic plants will grow 

naturally in a wetland over time; their seeds are 

often present in the soil before flooding or are 

carried in by birds and the wind. However, planting 

showy native flowering species does improve the 

appearance of a newly established vernal pond. 
You should now be ready to construct a vernal pond. This chapter guides you through the construction 

phase by building on the planning and site selection factors described in Chapter 2. Chapter 3 helps you to 

select and implement the best construction method for your location. It is recommended that you read this 

chapter in its entirety before building a vernal pond.

The best time to build a vernal pond is in the fall or during the driest time of the year. It is difficult to 

move, pack, and shape wet soil. Waiting until the ground is dry to begin construction can save both time and 

expense.

There are three main ways to construct an ephemeral wetland. The first involves making a shallow depression 

in the soil to trap rainfall. The second involves making a shallow depression in the soil that will fill with 

ground water. The third involves using a liner to trap rainfall. 4

17

chapter three • • • • • • • • • • Constructing a Vernal Pond

choosing a construction method

A. Water near surface of soil...................................B

A. Water not near surface of soil.............................C

B. Location over 0.25 miles from people and dwellings................................BLASTING

B. Location closer than 0.25 miles from people and dwellings................TRACK-HOE

C. Silt loam or clay soil present...............................D

C. Silt loam or clay soil not present.........................LINER

D. Silt loam or clay extends down to an impermeable layer..............................DOZER

D. Silt loam or clay is on top of a permeable layer...........................................................E

E. Small size wetland desired...................................LINER

E. Large size wetland desired...................................TRACK-HOE & DOZER

KEY TO CONSTRUCTION METHODS

Some people believe that one only has to dig a hole in the ground to make an ephemeral wetland. Too bad it 

isn’t this simple. Most holes in the ground don’t hold water. Natural, undisturbed ground is quite porous. It 

contains holes from roots, burrowing crayfish, and mammals such as the woodchuck. These holes need to be 

blocked to make an area hold water. Most ephemeral wetland construction techniques involve compacting 

the soil in a shallow depression to make it hold water. The soil is most often compacted with the tracks of a 

dozer.

Use the following key to identify the best construction method to use in building a vernal pond. The key uses 

information you obtain by testing the soil at the construction site.
A dozer is used to make a shallow depression in the soil that will trap rainfall for a vernal pond. The soil in 

the depression must have low permeability for this technique to work. Silt loam or clay textured soils can 

be used to make a vernal pond with a dozer. For your project, try to hire a dozer operator with experience 

building ponds. Such an individual has likely learned how to make ponds hold water for the soil conditions 

found in your area. Checking references and visiting previous work sites will give you an indication of the 

operators level of experience.

18

Remove and save topsoil. Make a core under the dam location.

The core is made out of silt loam or clay.

Dozer moves and packs soil in the core. Core is located under the entire dam.

• • • • • • • • • • Dozer Method • • • • • • • • • •

Wetland

Dam

Core

Silt Loam or Clay

Bedrock

Dozer moves soil in the core to eliminate holes.
19

The core will crush buried drainage tiles.

Seed and mulch the dam. Vernal pond constructed with a dozer.

The core needs to go below this exposed crayfish 

hole.

Make the dam on top of the core. Pack the dam in layers.

Make gradual slopes on the dam. Spread topsoil on the bottom of the wetland.
Use the dozer to construct a core beneath the dam. A core is critical to making a successful wetland. The 

core is an underground portion of the dam that is a barrier to water movement. It keeps water from leaving 

the wetland by traveling under the dam. A core should be made under the dam location before the dam is 

built.

Coring involves shifting and packing soil under the future dam. The core extends into the ground below the 

depth of holes made by crayfish, mammals, or tree roots. The core is usually made as wide as the dozer blade. 

It goes down to an impermeable layer of silt loam, clay, or rock. There is no need to remove soil from a core 

if is silt loam or clay. Permeable soil such as sand or gravel 

should be removed from the core, as they would allow water 

to pass under the dam. In some situations, an unexpectedly 

large amount of sand or gravel is found in the core during 

construction. It may be too costly to replace the permeable 

soil with impermeable soil. A decision would then need to be 

made to use a synthetic liner or to change work sites.

Using a dozer to make a dam on top of soil that has not been made into a core often results in a failed 

wetland. The coring process packs soil under the dam. Soil that is not compacted is quite porous. Most 

constructed wetlands that do not hold water have failed 

because of a bad core. A crayfish hole left intact under 

a dam may completely drain a wetland.

A dozer can make an excellent core. It is important 

to watch as the core is built. Look for holes at the 

surface. The dozer must dig down to the bottom of 

each hole. Some crayfish holes are 7 feet deep. Make 

sure that the entire hole is collapsed and packed. 

Stopping short of the bottom of the hole may allow a 

crayfish to re-dig the burrow, opening up a hole that 

will allow water to pass under the dam. Fortunately, 

not every wetland site has burrowing crayfish. A core 

may only need to be 2 feet deep if crayfish are not 

present. A core should be made even if a dam is not 

built. The core is made in these situations around the 

perimeter of the future wetland to keep water from 

seeping into the surrounding ground. 

Most heavy equipment operators do not understand 

the importance of a core. Making the core often takes 

longer than making the dam for a wetland.

20

remove and save the topsoil

make a core under the dam

Burrowing crayfish next to burrow.

Use the dozer to remove topsoil from the work area. Save the topsoil in a pile near the site to spread in the 

completed wetland. Topsoil should not be used in the dam or under the dam. Topsoil is dark in color and 

contains roots and organic material. It is porous and not suitable for making a dam. Topsoil often contains 

aquatic plant seeds. When re-spread in the bottom of a completed wetland it provides a rich substrate for 

aquatic plant growth.

Most wetlands fail because water leaks 

under the dam. You must compact the 

soil beneath the dam and remove any 

permeable material that may allow water 

to pass under the dam. a
Use the dozer to build a dam on top of the core. Make the dam with a series of soil layers less than 6 inches 

thick. Pack the soil in each layer with the tracks of the dozer before adding the next layer. Use a hand-held 

or tripod-mounted survey level and rod to make 

sure that the top of the dam is level. This helps 

you avoid accepting low places in the dam. Water 

would flow over the dam in these low places, 

causing erosion of the exposed soil.

Make a gradual slope on the front and the back of 

the dam. A 10:1 slope (1 foot of rise for every 

10 feet horizontal distance) looks natural. A 

dam with gradual slopes and a wide top holds up 

better to the frequent foot traffic experienced near 

schools and visitor centers. Such a dam is easier to 

maintain by mowing and is less likely to be damaged 

by muskrats. 

21

build the dam

make a spillway

One-year-old vernal pond that blends into the landscape 

due to the dam being constructed with a gradual slope.

Cross section of dam and spillway. The spillway provides a path for water to leave the 

wetland.

SPILLWAY

Spillway

Dam

Undisturbed Soil

The spillway should be 6 inches to 1 foot lower than the top of the dam. The spillway is generally the 

width of one dozer blade. A narrow spillway will erode into a deep trench. Care should be taken to 

vegetate the spillway after construction. A grassy spillway will accommodate water leaving most wetlands. 

The spillway may need to be lined with rock if the wetland has a large watershed.

One should make the spillway after the dam is built. Use a hand-held or tripod-mounted survey level and rod 

to identify the lowest place in the dam. Set the elevation of the spillway 6 inches

to 1 foot below the lowest place in the dam. Try to visualize how water will flow out of the wetland. You 

want it to follow the path of the spillway.

Making an ephemeral wetland with a dam over 3 feet high requires special attention to how water leaves the 

wetland. Water that flows over a dam may wash out the dam, causing a considerable amount of erosion. A 

spillway is used to protect the dam from damage. Overflow water can be made to leave the wetland over the 

spillway. The spillway is a wide, gradually sloped path of undisturbed soil located next to the dam that allows 

excess water to travel around the dam.
Installing a drainpipe in a vernal pond provides management options at a relatively low 

cost. A drain allows you to achieve a desired wet-dry cycle by intentionally drawing down 

water. You may easily remove unwanted fish species and complete repairs by opening the 

drainpipe.

PVC pipe that is joined together with gaskets should be used for draining ephemeral 

wetlands because glued joints may break under freezing conditions. Schedule 35 or 

Schedule 40 SDR PVC gasket pipe is readily available at plumbing supply stores at a 

reasonable price. PVC pipe is lightweight, easy to install, and does not leak or rust. A 6-

inch-diameter pipe is large enough to drain most any ephemeral wetland. Install a drainpipe 

in the deepest part of the ephemeral wetland. During construction, the drainpipe is 

placed on top of the completed core just before the dam is built. The dam is built over 

the drainpipe to compact the soil around the pipe. Many pond construction manuals 

recommend that an anti-seep collar be placed around the drainpipe; these collars are 

unnecessary for ephemeral wetland construction.

A drainpipe can be modified to serve as a water control structure. One can attach a 

gasketed 90 degree elbow with a pipe extension to the inlet of the drainpipe. Water levels 

may be adjusted or drained by rotating the elbow and overflow pipe parallel to the bottom 

of the wetland.

22

install drainpipe

This PVC pipe serves as an overflow pipe 

when vertical; the stake provides support 

to the pipe.

The same pipe can be moved parallel to 

the ground to drain the wetland.

finishing touches

You may have extra soil left after building an ephemeral wetland. Spread the excess soil 

around the ephemeral wetland. You can taper the soil to blend into the surrounding 

landscape. Don’t use the extra soil to make a “donut” shaped dam around the ephemeral 

wetland. Such a ring of soil can keep water run off from entering the wetland. It also looks 

artificial. Spread the topsoil in the bottom of the new vernal pond and shape the soil so 

that it blends with the landscape.
If you determine that you will be working on a site that has a layer of silt loam on top of gravel, you 

can make a small vernal pond by using a synthetic liner as described later in this chapter. However, if 

you want to make a large vernal pond, you will need to give special attention to building the core under 

the dam; a track-hoe is recommended. This is especially important if you are working in an area where 

crayfish are present. Crayfish will burrow down through the silt loam in the bottom of the wetland to 

the gravel. Rainfall will then follow the crayfish burrow to the gravel layer. Water will leak out of the 

wetland by following the gravel layer that extends under the dam.

Follow the steps outlined in the DOZER METHOD section to make a large vernal pond on a site that has 

silt loam on top of gravel. Then follow these additional steps to insure success when making the core.

23

• • • • • • • • • • Track-Hoe and Dozer Method • • • • • • • • • •

the kentucky experience

Vernal ponds over two acres in size have 

been made in eastern Kentucky where silt 

loam occurs on top of gravel. a

Two-year-old wetland constructed in a site 

with silt loam on top of gravel. This core 

extends 12 feet down into the ground. 

(A) Use a track-hoe to dig a wide trench that will form the core. Dig the 

trench as wide as the blade on a dozer.

(B) Dig the trench wide enough for a dozer to go down into the 

bottom for packing the soil.

(C) Have the track-hoe remove the silt loam from the top of the trench and 

place it along the inside edge of the wetland.

(D) Use the track-hoe to remove the gravel from the bottom of the 

trench and place it outside of the wetland. The gravel may later be 

used to make the backside of the dam.

(E) Dig the trench down to an impermeable layer such as bedrock or clay. In 

some places you may need to dig down 14 feet to find an impermeable 

layer.

(F) Use a dozer to fill the trench with silt loam soil. Pack the soil in 

the core trench well with the dozer. The goal here is to make an 

“underground” dam.

(G) Construct the dam on top of the core.
Wetland

Dam

Core

Gravel

Silt Loam or Clay

Bedrock

24

The core prevents water from leaking under 

the dam.

Five-year-old wetland built with a track-hoe 

and dozer.

Track-hoe digs a trench down to bedrock to form 

the core.

As the trench is being dug, silt loam is placed 

inside the wetland; gravel outside the wetland.

Dozer fills the core trench with silt loam. Dozer packs soil in layers to build a dam above 

the core.

making a wetland with a track-hoe and dozer
You may need to sandwich a fabric pad under and over the liner to protect it from puncture by sharp rocks 

and sticks in the soil. The fabric pads also keep tree roots from penetrating the liner. These fabric pads are 

called “geo-textile” or “geo-pads.” They are similar to a strong synthetic blanket and may be purchased from 

the same companies that sell synthetic liners. Research conducted on PVC liners used in landfills indicates 

that an ephemeral wetland constructed with a synthetic liner that is covered with soil (described above) 

should last for 30 years or more.

Here are the steps to follow when using a liner to make a vernal pond:

25

• • • • • • • • • • Liner Method • • • • • • • • • •

use a quality liner

protect the liner

Fab-Seal Industrial Liners, Inc.

42404 Moccasin Trail

Shawnee, OK 74804

1-800-874-0166

http://www.fabseal.com

Just Liners, Inc.

35507B Clearpond Road

Shawnee, OK 74801

1-888-838-4017

http://www.justliners.com

(A) Use a dozer to dig a shallow depression in the soil. Make the depression 6 to 8 inches deeper 

than the desired water depth so that soil can later be placed over the liner. A small dam may 

need to be built along a low end of the site to make the outer edge of the wetland level.

(B) Place a geo-textile pad in the depression. The geo-textile pad protects the liner from puncture by 

sharp rocks or sticks.

(C) Place the synthetic liner on top of the geo-textile pad.

(D) Place another geo-textile pad on top of the synthetic liner.

(E) Anchor the top edges of the synthetic liner and geo-textile fabric pads with wire stakes or 

large nails with washers placed approximately 24 inches apart. The stakes keep the liner 

from being pushed down into the depression when it is being covered with soil.

A liner is needed to insure that a wetland will hold water if the soil on a desired site consists of sand, gravel, or has 

buried fill from previous construction. Liners are expensive and you may need to limit the size of your vernal pond 

to stay within budget. Reminder: The soil on a site is most likely sand or gravel if you cannot make a ribbon that is 

two inches long between your thumb and forefinger.

It is difficult to make a wetland larger than 30 feet wide and 40 feet long with a liner. Liners are heavy and 

challenging to move into position. Commercial liners that are used for landfills work well for ephemeral 

wetlands. These can be made to most any size. Make sure that the liners you order are “fish grade” or 

“aquatic safe.” These do not contain toxic chemicals that kill aquatic life. Do not use tarps or plastic drop 

cloths from the department store. These are thin and puncture easily. Synthetic liners are readily available 

from a number of sources. Liners made of EPDM (ethylene propylene monomer) that is 45 mils thick, or 

PCV (polyvinyl chloride) that is 30 mils thick, work well. These companies sell synthetic liners to companies 

as well as individuals:
26

A dozer makes a shallow depression in the soil. A liner is placed in the depression.

The liner is protected on both sides by geo-textile 

fabric.

The liner is secured with stakes.

A dozer is used to cover the liner with soil. Two-year-old vernal pond made with liner.

using a liner to make a vernal pond
Use the dozer to cover the liner with 6 to 8 inches of soil. The dozer will not harm the liner as long as 

it rides on top of soil that it is pushing over the liner. Avoid turning the dozer while on top of the liner. 

Turns will tear the liner. The soil protects the liner from being punctured by deer and horse hooves. It also 

protects the liner from sunlight deterioration and provides a substrate for plant growth. Amphibians and 

insects may spend the winter on the bottom of the wetland in the soil placed over the liner. Seed and mulch 

the exposed soil to reduce erosion.

It is possible to dig a vernal pond by hand with a shovel. This may be a tempting option if you have access 

to inexpensive labor such as students or relatives. However, a hand-dug wetland may not hold water due 

to low compaction. Consider using a liner in a hand-dug wetland to insure success. To make a large vernal 

pond with a liner, use a dozer or backhoe to move the greater quantity of soil.

27

This group of Boy Scouts hand-dug two 

10-foot diameter vernal ponds in one day.

They removed sharp sticks and rocks.

After placing the liner, they covered it with soil. They seeded and mulched the exposed soil.

Four months later...

cover the liner with soil

using hand tools to install a liner
You may hear a suggestion to place a layer of clay or bentonite in the bottom of a leaking constructed 

wetland to make it hold water. This technique rarely works. Wetlands leak for a variety of reasons. The most 

common is that water from the wetland is going under the dam. Placing clay in the bottom of a wetland 

where water is seeping under the dam may provide a short-term fix; however, all it takes is one crayfish 

or muskrat to dig a hole in the clay and the wetland will leak again. A synthetic liner sandwiched between 

two geo-textile pads and covered with 6 inches of soil provides a more permanent fix for a leaky wetland. 

However, a layer of clay may repair a leaky wetland built from sandy soils where burrowing crayfish are not 

present.

28

plastic tubs

clay liners

Small vernal pond hand-dug in clay soil by iron ore 

miners in 1850. (Teresa Brasfield photo)

Waterfowl find valuable food in this 6-year- old 

ephemeral wetland where annual plants are 

inundated by fall rain.

• • • • • • • • • • High Water Table Sites • • • • • • • • • •

Preformed molded plastic tubs used for landscaping can be used to make a very small vernal pond. A plastic 

tub may be the only way to make a vernal pond on a site with sharp, rocky soil. Most of these tubs are made 

with vertical sides that should not be used. Only tubs with gradually sloped sides should be used to make 

vernal ponds. Tubs with vertical sides can become deathtraps for amphibians, reptiles, and mammals as water 

levels drop. It is possible to use rocks, soil, or galvanized wire mesh to make an escape ramp for animals to 

climb out of the water. However, these escape ramps require regular maintenance to keep them functional.

Making a shallow depression in the soil that fills with ground water often results in a vernal pond on a 

location with a high water table. Working in saturated soils takes some ingenuity. It is easy for an operator 

to get heavy equipment hopelessly stuck on these sites. There are two proven techniques for building vernal 

ponds on areas with water near the surface. The first involves heavy equipment, the second explosives.
 A track-hoe is an effective way to make a small ephemeral wetland on an area with saturated soil. An 

experienced operator can move the track-hoe into and out of soft areas where a dozer would get stuck. A 

contractor needs a somewhat open area for operating the track-hoe as the large boom and bucket swing 

widely, making it difficult to avoid hitting adjacent trees.

Here are some steps to follow when using a track-hoe to make an ephemeral wetland: 

29

(A) Determine how deep you would like the vernal pond.

(B) Mark the perimeter of the vernal pond with plastic ribbon or wire flags.

(C) Use a track-hoe to dig a hole for the vernal pond.

(D) Slope the sides of the depression so that the wetland appears natural.

(E) Seed and mulch exposed soil to reduce erosion.

Track-hoe making a vernal pond in a wooded area. This vernal pond was built with a track-hoe on a 

site with a high water table.

the kentucky experience

A track-hoe can make over 20 small 

wetlands a day if sites are near one 

another. a

Two-year-old vernal pond 

constructed with a track-hoe. 

track-hoe method
Explosives have been used to make ephemeral and permanent water wetlands for years. The technique can 

be used successfully in areas that cannot be reached by heavy equipment. Blasting is relatively inexpensive and 

results in a natural appearing ephemeral wetland.

Contact a licensed blaster if you are interested in using this technique. A licensed blaster may legally purchase, 

transport, store, and use the explosives needed to make an ephemeral wetland. You may find the name 

of a licensed blaster by looking in the Yellow Pages under “explosives.” You may also phone an explosives 

distributor and ask for the name(s) of licensed blasters who work in your area. The International Society of 

Explosives Engineers (http://www.isee.org/) is also a good place to ask for help. The USDA Forest Service 

maintains a cadre of certified blasters who are available to help on National Forest System land. The forest 

blaster or regional blasting examiner would direct the use of blasting to establish wetlands in a national forest.

The explosives method may be safely used if a site is more than one-quarter mile from people, homes, utility 

lines, and other improvements. The actual blast may launch rocks and debris a considerable distance.Individuals 

with the Missouri Department of Conservation found that it takes a much greater quantity of explosives to 

make a wetland when the ground is frozen.

Water gel explosive works well to make a vernal pond in wet areas. Water gel explosive is readily available 

from companies that distribute explosives. A commercial mix of ammonium nitrate fertilizer and fuel oil (AN/

FO) may also be used. AN/FO is more difficult to use than water gel as it must be kept dry up to detonation, 

but is the lowest priced explosive available for making a vernal pond.

Here are steps to follow when using explosives to establish a vernal pond:

30

(A) Determine how deep you would like the wetland.

(B) Mark the perimeter of the future wetland with plastic ribbon or wire flags.

(C) Enlist the help of a licensed blaster to design and implement the project.

(D) When blasting, make sure people and structures are a safe distance away from your 

activities.

(E) Set the AN/FO in hand-dug holes where you would like the vernal pond. Place 

the AN/FO in plastic bags. The top of the bag should be even with the surface of 

the ground.

(F) Seed and mulch exposed soil after detonation. There is no need to slope the sides of 

the new wetland. The loose soil will settle and appear natural in a few years. 

blasting method
Constructed ephemeral wetlands should be inspected at least once a year. Visiting them more often will tell 

you if they contain water as planned. Examine the dam to see if water has been flowing over it, which can 

cause erosion. You may need to clean branches and logs from the spillway so that excess water may continue 

to flow around the dam.

Muskrats, dogs, and woodchucks can dig holes in a 

dam. Holes that cause the wetland to leak are best 

repaired with a backhoe. The dam itself should be 

mowed once a year to control trees and shrubs, as 

their roots can weaken the dam and cause it to leak.

 

An inspection will identify whether or not all 

terrain vehicles or livestock are damaging the 

wetland. An inspection may also identify dense 

cattail growth that you may want to reduce. 

Muskrats may eventually control 

cattails in ephemeral wetlands over one-half acre in 

size. Should cattails grow too thick in a small vernal 

pond, you should be able to control them by simply 

hand-pulling. Cattails may be controlled in a larger 

wetlands by removing the water for two consecutive summers or by mowing when the site is dry. 

31

AN/FO is placed in a shallow hole.

Site immediately after blasting. Site six years later.

A licensed blaster detonated the AN/FO.

• • • • • • • • • • Maintenance • • • • • • • • • •

Dense growth of cattails in a 3-year-old vernal pond.
Sources of information

Here are some sources of 

information about constructing 

vernal ponds, the species that 

use them, and how to teach 

students about wetlands:

32

chapter four • • • • • • • • • • Reference Material

This vernal pond is 8 years old.

Kenney, Leo P. and Matthew R. Burne. 2000. A Field Guide to the Animals of Vernal Ponds. Massachusetts 

Division of Fisheries and Wildlife, Natural Heritage & Endangered Species Program & Vernal Pool Association, 

Route 135, Westborough, MA 01581. (508) 792-7270 ext. 200. 

http://ww.state.ma.us/dfwele/dfw/dfwnhes.htm or http://www.vernalpool.org/. 

Kenney, Leo P. Diving Into Wicked Big Puddles, An Educator’s Resource Kit for the Study and Teaching of Vernal 

Pool Ecology. The Vernal Pool Association, Reading Memorial High School, 62 Oakland Road, Reading, MA 01867. 

http://www.vernalpool.org.

Kingsbury, Bruce and Joanna Gibson. 2002. Habitat Management Guidelines for Amphibians and Reptiles of the 

Midwest. Partners in Amphibian and Reptile Conservation (PARC), 57 pp. 

http://wwww.parcplace.org. A web-based version of this guide is available at:

http://herpcenter.ipfw.edu/.

Maine Citizen’s Guide To Locating and Documenting Vernal Pools. August 1999. Maine Audubon Society, 

P.O. Box 6009, Falmouth, ME 04105 (207) 781-2330.

Midwestern Ephemeral Wetlands. Environmental Protection Agency

http:/herps.ipfw.edu/wetlands/ephemeral/.

Project WET. 1995. K-12 Curriculum and Activity Guide. The Watercourse and the Council For Environmental 

Education, 201 Culbertson Hall, Montana State University, Bozeman, Montana 59717-0570. http://

www.montana.edu/wwwwet.

Ripple, Karen L. and Edgar W. Garbisch. 2000. POW! The Planning of Wetlands, An Educator’s Guide. 

Environmental Concern Inc., P.O. Box P., 201 Boundary Lane, St. Michaels, Maryland 21663.

http://www.wetland.org. 

Szafoni, R.E., C.A. Phillips, S.R. Ballard, R.A. Brandon, and G. Kruse. 2002. Illinois landowner’s guide to 

amphibian conservation. Illinois Natural History Survey Special Publication 22. iv + 26pp.

Thompson, Alice L. and Charles S. Luthin. 2000. Wetland Restoration Handbook for Wisconsin Landowners. 

Wisconsin Department of Natural Resources, P.O. Box 7921, Madison, WI 53707.

USDA 1997. Ponds-Planning, Design, Construction. Agriculture Handbook Number 590. Natural Resource 

Conservation Service. 85pp.

USDA 2000. Guide for using, storing, and transporting explosives and blasting materials. Forest Service. Technology 

and Development Program, 6700 Safety and Health, Chapter 10: Specialty Blasting. August 2000. 0067-2803-

MTDC.

WOW! The Wonders of Wetlands, An Educator’s Guide. 1995. Environmental Concerns Inc. and The 

Water Course, P.O. Box P, St. Michaels, MD 21663-0480. 
33

Vernal Pond Construction, Supply, & Budget Needs

(as of 2002)

• • • • • • • • • •

Vernal Pond, 60-foot diameter, dozer method:

A) Dozer contract (5 hours @ $60/hour) $300.00

B) Grass seed for exposed slopes (20 lbs. @ $1.20/lb) 24.00

C) Winter wheat for exposed slopes (1-50lb. bag @ $6.50/bag) 6.50

D) Straw for mulch (15 bales @ $3.75/bale) 56.25

 Total: $386.75

Vernal Pond, 30 by 40 feet, liner method:

A) Dozer contract (5 hours @ $60/hour) $300.00

B) Synthetic liner (PVC, 30 mil): 1,200 square feet @ $0.38/square foot 456.00

C) Geo-textile fabric to place above and below synthetic liner:

 2(1,200 square feet @ $0.25/square foot) 600.00

D) Wire stakes to anchor top edge of liner (50 @ $0.25/each) 12.50

E) Grass seed for exposed slopes (20 lbs. @ $1.20/lb) 24.00

F) Winter wheat for exposed slopes (1-50lb. Bag @ $6.50/bag) 6.50

G) Straw for mulch (15 bales @ $3.75/bale) 56.25

 Total: $1,455.25

Vernal Pond, 60-foot diameter, track-hoe method:

A) Track-hoe contract (5 hours @ $90/hour) $450.00

B) Grass seed for exposed slopes (20 lbs. @ $1.20/lb) 24.00

C) Winter wheat for exposed slopes (1-50lb. bag @ $6.50/bag) 6.50

D) Straw for mulch (4 bales @ $3.75/bale) 15.00

 Total: $495.00

Vernal Pond, 30-foot diameter, explosives method:

A) AN/FO, boosters and cord $250.00

B) Licensed blaster fee 250.00

B) Grass seed for exposed slopes (15 lbs. @ $1.20/lb) 18.00

C) Winter wheat for exposed slopes (0.5-50lb. bag @ $6.50/bag) 3.25

D) Straw for mulch (3 bales @ $3.75/bale) 11.25

 Total: $532.50

Vernal Pond, 2-acre size, dozer method:

A) Dozer contract (40 hours @ $60/hour) $2,400.00

B) Grass seed for exposed slopes (50 lbs. @ $1.20/lb) 60.00

C) Winter wheat for exposed slopes (3-50lb. bags @ $6.50/bag) 19.50

D) Straw for mulch (50 bales @ $3.75/bale) 187.50

E) Fertilizer for dam (4-50lb. bags @ $6.50/bag) 26.00

F) Lime for dam (20-50lb bags @ $1.20/bag) 24.00

G) Drainpipe (52 feet @ $1.10/foot) 57.20

H) 90 degree elbow for water control structure 4.50

 Total: $2,778.70
Two-year-old constructed vernal pond.

Natural vernal pond. 

(Teresa Brasfield photo)

Discover how to make an ephemeral wetland 

that looks and functions like a natural wetland.