Freshwater Wetlands - Hydro-Environmental Analysis: Freshwater Environments - page 519

looding of the Mississippi River. The control of the mighty Mississippi remains a problem today,
as noted by Mark Twain in his Life on the Mississippi :

One who knows the Mississippi will promptly aver … that ten thousand River Commissions, with the
mines of the world at their back, cannot tame the lawless stream, cannot curb it or conine it, cannot say
to it Go here or Go there, and make it obey; cannot save a shore that it has sentenced.

The attempted control of the Mississippi River was initiated early in U.S. history, such as the ini-
tial construction of a man-made levee system by Bienville, the founder of the city of New Orleans,
in 1717. The responsibility of the Mississippi levee system was ultimately delegated to the Corps
and since 1882, the Corps in conjunction with the Mississippi River Commission has maintained
and extended the levee system. The levee system, while providing lood control, also isolated the
bottomland hardwood wetlands that were common along the Mississippi River valley. More than
75% of the historic bottomland hardwood wetlands in the lower Mississippi valley have been lost
(Dahl 1990; Dahl and Allord 1996). As stated frequently elsewhere in this text, it is often common
that “one generation's solution is the next generation's problem,” or for engineers “one generation's
solution is the next generation's job.” For example, currently, there are a variety of wetland restora-
tion activities along the Mississippi River corridor and elsewhere for the purposes of lood control,
nutrient management, habitat enhancement, and other beneicial uses.
By the 1960s, a variety of political, inancial, and institutional incentives to drain or destroy wet-
lands was in place (Dahl and Allord 1996). During this time, an increasing awareness of the values
of wetlands resulted in increasing efforts at their protection and restoration. Federal policies have
shifted to eliminate many of the incentives for the destruction of wetlands, and new laws, such as
the CWA in 1972 and the Emergency Wetland Resources Act of 1986, have further protected and
curtailed wetland losses. In 1974, the U.S. Fish and Wildlife Service initiated an inventory of the
nation's wetlands. The 1986 act also required that the Fish and Wildlife Service update the initial
wetlands status and trends information every 10 years and provide a report to Congress.

• The “Status and trends of wetlands and deep-water habitats in the conterminous United

States, 1950's to 1970's” (Frayer et al. 1983) reported: “Total acreage of wetlands and deep-
water habitats in the 48 conterminous United States in the 1950's was 179.5 million acres.
In the 1970's it was 171.9 million acres, a net loss of 7.6 million acres. Average annual net
loss for the 20-year period was 380 thousand acres.”

• The “Status and trends of wetlands in the conterminous United States, mid-1970's to mid-

1980's” (Dahl and Johnson 1991) reported that: “there were an estimated 105.9 million
acres of wetlands in tile conterminous United States in the mid·1970's. In the mid-1980's,
there were 103.3 million acres of wetlands. This translates into a net loss of over 2.6 mil-
lion acres over the study period. Freshwater wetlands experienced 98.0 percent of the losses
that occurred during the study period. By the mid-1980s, an estimated 97.8 million acres
of freshwater wetlands and 5.5 million acres of estuarine (coastal) wetlands remained.”

• The “Status and trends of wetlands in the conterminous United States 1986 to 1997” (Dahl

2000) reported that: “An estimated 105.5 million acres of wetlands remained in the con-
terminous United States in 1997. Between 1986 and 1997, the net loss of wetlands was
644,000 acres. The annual loss rate during this period was 58,500 acres, which represents
an eighty percent reduction in the average annual rate of wetland loss as compared to the
last wetlands status and trends report” (Dahl and Johnson 1991).

• The “Status and trends of wetlands in the conterminous United States 1998 to 2004” (Dahl

2006) reported that: “there were an estimated 107.7 million acres of wetlands in the conter-
minous United States in 2004.” “Wetland area increased by an average 32,000 acres annu-
ally” and that “agricultural conservation programs were responsible for most of the gross
wetland restoration.” Additionally, “despite the net gains realized from restoration and