Freshwater Wetlands - Hydro-Environmental Analysis: Freshwater Environments - page 518

Washington

Red Lake

Maine

Montana

North Dakota Erie

Canal

Oregon Vermont

New
Hampshire
Massachusetts
Rhode Island
Connecticut
New
Jersey
Delaware
Maryland

Lake
Ontario

Minnesota

Idaho

Wisconsin
Horicon
Marsh

South Dakota

New York

Michigan

Wyoming

Pennsylvania

Iowa

Nebraska

Nevada

Ohio

Explanation
Percent of wetlands
lost, 1780s to mid-1980s
Less than 50

Indiana

Utah

Illinois

Mississipi River River West

Virginia

Colorado

Kansas

California

Missouri Virginia

Kentucky

North
Carolina

50-85 (16 states)
More than 85 (6 states)

Tennessee

Arizona

Oklahoma Arkansas

South
Carolina

New Mexico

Mississippi

Georgia

Alabama

Okefenokee
Swamp Louisiana

Texas

Florida

0 500 miles

“e
Everglades

0 500 kilometers

FIGURE 19.8 States with notable wetland loss, 1780s to mid-1980s. (From Dahl, T.E., Status and trends of
wetlands in the conterminous United States 1986 to 1997. U.S. Department of the Interior, Fish and Wildlife
Service, Washington, DC, 1990; From Dahl, T.E. and Allord, G.J., National Water Summary on Wetland
Resources , U.S. Geological Survey, Washington, DC, 1996.)

During the period from the early 1600s to the 1800s, a period of colonial development, relatively
few records existed to document the extent and change in wetlands. It was not until 1785 that the
Land Ordinance Act established the U.S. Public Land Survey, which required that in surveying
land, some quantitative information was available on the extent of wetlands. During this period of
extensive agricultural development, wetlands were considered an impediment to development, and
were often converted to farmland, particularly in the most southern of the original colonies (Dahl
and Allord 1996).
The period from 1800 to 1860 was a period of growth and westward expansion. This period
included the Louisiana Purchase (1803) and the annexation of Texas (1845). It also included exten-
sive agricultural development and the drainage of wetlands. The Swamp Land Acts in 1849, later
modiied in 1850, granted all swamp and overlow lands to states for “reclamation,” irst in Louisiana
and then in 12 additional states (Shaw and Fredine 1956; Dahl and Allord 1996), establishing the
prevailing tone and policy for land use trends for the next century.
During 1860-1900, westward migration continued and, with technological advances, the con-
version of wetlands to farmlands rapidly increased. This rapid conversion continued during the
1900s to 1950, and by the 1920s about 70% of the original wetland acreage had been modiied by
levees, drainage, and water diversion projects (Frayer et al. 1989, cited in Dahl and Allord 1996).
The development of mechanical tractors allowed large areas of wetlands and prairie potholes to
be drained. By the 1930s, large portions of the Florida Everglades had been drained. Flooding in
Florida prompted the Corps to build the Central and Southern Florida Project for lood control,
which resulted in very substantial losses of wetlands. This period also included the proliferation
of organized drainage districts throughout the country that coordinated efforts to remove surface
water from wetlands (Wooten and Jones 1955, cited in Dahl and Allord 1996). During the 1930s,
the U.S. government basically provided free engineering services to farmers to drain wetlands and,
by the 1940s, it shared the cost of drainage projects (Burwell and Sugden 1964, cited in Dahl and
Allord 1996).
In addition to the dewatering of large portions of the Florida Everglades, one other particularly
notable effort that resulted in enormous losses of wetlands was that targeted at the control of the