Wetland Alterations

Water Level

draining

channeling

construction of dams

filling

water extraction

highway construction

Nutrient Level

sewage

agricultural runoff

sediments

Man Made Disturbances

discharge of toxic substances

acid mine drainage

mineral extraction (phosphates, gravel, sand)

peat extraction

Natural Disturbances

subsidence

drought

hurricanes

erosion

biotic effects - "eat-outs"

Return to Week 6 - Lecture 1
Return to overhead index

Trend of Drained Agriculture Land

Fig. 16-3. Trend of drained farmland in the U.S. from 1900 to 1980 (Gosselink and Maltby, 1990, based on data from Office of Technology Assessment, 1984)

Return to Week 6 - Lecture 1
Return to overhead index

Historical Wetland Loss

Fig.30. Historical losses of wetlands in Iowa and California.(from Bishop 1981 and U.S. Fish and Wildlife Service 1977).

Return to Week 6 - Lecture 1
Return to overhead index

Historical Wetland Loss - Coastal

Fig 31.Rate of coastal wetland loss in the conterminous U.S. (from Gosselink and Bauman 1990). Estimates include both estuarine and tidal freshwater wetland losses.

Return to Week 6 - Lecture 1
Return to overhead index

Coastal Wetland Conversions

Fig 6. Fate of converted estuarine emergent(coastal) wetlands, min-1970's to mid-1980's.

Return to Week 6 - Lecture 1
Return to overhead index

Palestrine Wetland Loss / Gain

Fig.7. Palustrine wetland gains and losses, mid-1970's to mid-1980's.

Return to Week 6 - Lecture 1
Return to overhead index

Non-Federal Wetland Loss 1982- 1987

Table 2. NRI-based estimates of wetland area in 1982 and 1987 (in 100's of ha)

Region	Total Area '82....................'87	Area lost........gained	Retained(%)	Net Change (1987-1982)	Change(%)
West	2628.3.........2476.7	157.3........5.7	94.0	-151.6	-5.77
Midwest	10347.3......10314.0	51.6........18.3	99.5	-33.3	-0.32
Southwest	14983.7......14847.6	140.2........4.1	99.1	-136.1	-0.91
Northeast	5531.8..........5489.6	43.8..........1.6	99.2	-42.2	-0.76
Total	33491.1......33127.9	393.9......29.7	98.8	-363.2	-1.08

*Wetlands that were involved in a transfer of ownership between federal and nonfederal land are not included in these estimates.

Return to Week 6 - Lecture 1
Return to overhead index

Wetland Loss in U.S.

Fig 1.States that lost more than 50% of their wetlands between the 1780's and mid-1980's (listed states shaded)(after Dahl 1990)

State	% Lost	State	% Lost
Alabama	50	Maryland	73
Arkansas	72	Michigan	50
California	91	Mississippi	59
Colorado	50	Missouri	87
Connecticut	74	Nevada	52
Deleware	54	New York	60
Idaho	56	Ohio	90
Illinois	85	Oklahoma	67
Indiana	87	Pennsylvania	56
Iowa	89	Tennessee	59
Kentucky	81	Texas	52

Return to Week 6 - Lecture 1
Return to overhead index

Total Wetland Loss

Fig 27. Original and remaining acreages of wetlands in the counterminous U.S. (from Roe and Ayres 1954; Frayer,et al., 1983).

Return to Week 6 - Lecture 1
Return to overhead index

Wetland Conversions

Uses	1950-1970	1970-1980	1980-1990
Agriculture	87%	54%	37%
Urban	8	5	48
Open Water/Barren	-	-	15
Forest	-	-	-
Other	5	41	-

Return to Week 6 - Lecture 1
Return to overhead index

History of Wetland Regulations

1849 - Swamp Land Act (Amended in 1850,1860).

1890 - Rivers and Harbors Act (Amended in 1899).

1960 - Supreme Court broadly construes RHA to include industrial waste.

1967 - Fish and Wildlife Coordination Act.

1968 - MOU between DOI and ACOE.

1970 - Supreme Court upheld denial of RHA permit for ecological reasons.

1970 - Executive Order 11574.

1972 - Federal Water Pollution Control Act.

1975 - Court Cases expand CWA into wetlands.

1975 - ACOE Regulations in Phase.

I } 1975 - Tidal and Waters used for commercial navigation.

II} 1976 - Tributaries to Phase I and lakes > 5 acres.

III} 1977 - All waters of U.S.

1977 - CWA Amended.

1977 - Executive Order 11990.

1977 - ACOE Amends Regulations.

1979 - U.S. Attorney General - EPA Authority of Jurisdictional Issues.

1980 - EPA -404 - (b)(1) Guidelines.

1981 - Executive Order 12291

1983 - ACOE Proposed Reforms.

1983 - EPA Resists.

1984 Court Case - ACOE Concedes.

1986 - ACOE Amends Regulations.

1989 - MOU Between ACOE and EPA - jurisdiction.

1990 - MOU Between ACOE and EPA - mitigation.

1992 - Court Cases - Isolated Wetlands.

1993 - Court Case - CWA regulates excavation.

1995 - Amendment to Nationwide Permits

Return to Week 6 - Lecture 1
Return to overhead index