Ducks Unlimited

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The Scientific Foundations of the Clean Water Act
Scott C. Yaich, Ph.D. Director of Conservation
Operations National Headquarters, Memphis
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Clean Water ActPurpose

• to restore and maintain the
• chemical, physical, and biologic
• integrity of the Nations waters

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Context
Over 53 of the nations wetlands had been lost
by the 1980s
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Solid Waste Agency of Northern Cook County
(SWANCC)

• January 2001 U.S. Supreme Court decision
• Ruling Use of wetlands by migratory birds
• could not be used as the sole basis
• for exerting federal CWA jurisdiction

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DU Estimates of Wetlands No Longer Protected by
the CWA
Numbers Acres
Prairie Potholes 96 76 Gulf Coast
96 86 Great Lakes
90 33 Mid-Atlantic Coast
88 12 Lower Miss. Valley 63
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Rapanos/Carabell Supreme Court Case

• 40-80 of remaining wetlands in
• the U.S., or 40-80 million acres

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Some of Kennedys Key Points Wetlands possess
the requisite nexus if the wetlands, either
alone or in combination with similarly
situated lands in the region, significantly
affect the chemical, physical and biological
integrity of other covered waters more readily
understood as navigable.
the Corps jurisdiction depends upon the
existence of a significant nexus between the
wetlands in question and navigable waters in
the traditional sense. Includes ecological
factors such as flood control, water filtration
and habitat
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Justice Kennedy Given the role wetlands
play in pollutant filtering, and runoff
storage, it may well be the absence of
hydrologic connection (in the sense of
interchange of waters) that shows the
wetlands significance for the aquatic
system.
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Science.
must be the foundation for resolution
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Clean Water Act,Wetlands and Nexuses

• Linkages of wetlands and waters of the U.S.
• Direct surface flow to navigable waters
• Surface connections via tributaries
• Groundwater connections
• Ecological connections

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Surface Water Storage and Flood Abatement
Abatement of flooding by lowering and moderating
the peaks of flood stages, thereby reducing flood
damages
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Wetland Functions
Flood Water Storage flood damage 3.7
billion/year in U.S.
1988-97 National Disaster Education Coalition
Losing 1 of a watersheds wetlands can increase
total flood volume by almost 7
More flood for less rain
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Wetland Loss
(percent of original wetlands)
-27
-49
-42
-46
-35
-38
-89
-35
-90
-85
-87
-24
-50
-48
-87
-81
-59
-67
-72
-59
-46
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Wetland Loss
(million acres)
0.31
2.44
6.40
4.47
0.96
0.75
3.58
1.01
4.52
6.96
4.85
0.03
1.00
0.43
4.20
1.27
1.15
1.89
7.09
5.80
7.40
Total gt60 million acres
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Wetland Functions Water Storage
1993 Midwest Floods

• Largest flood disaster in U.S
• history
• 16B damages

• IL, IA MO had 75 of damage
• (11.8B)
• Wetland losses of 89, 85, 87

Galloway Report 1994 GAO 1995 Myers and White
1993
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Over 75 of flood damage worldwide is caused by
less than one foot of water
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Surface Water Storage and Flood Abatement

• Presence of wetlands were a significant
• factor in reduction of 50 and 100-year
• floods
• MN watersheds annual floods were
• inversely related to percentage of lakes
• and wetlands

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Surface Water Storage and Flood Abatement

• Significant increase in peak stream
• flows for all size streams as wetlands
• removed from the watershed
• Presence of many GI wetlands decreased
• runoff velocity and volume extended
• release of water

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Prairie Pothole Region
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Red River Basin1

• 74 converted to agricultural use
• 75 of wetlands drained
• Thousands of miles of drainage

1 Manale et al 2006 EERC-Univ. of ND
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Red River Basin1

• Major floods every 4-6 years
• Devastating flood every 10 yrs
• 95 probability of flood within 12
• years of last flood event

1 Manale et al 2006 EERC-Univ. of ND
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• gt95 of the potholes in MN and IA
• have been drained or filled
• Originally 7.6M acres in IA
• Reduced to lt30,000 acres by 1980

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Groundwater Connections

• Prairie potholes serve as groundwater
• recharge sites
• Recharge from small PPR depressions
• constitutes large proportion of total
• recharge in many areas
• Smallest potholes proportionately
• more important to groundwater
• connectivity

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Groundwater Connections
CA vernal pools have high rate of seepage
and contributions to subsurface flow
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Groundwater Connections

• NE sandhill wetlands important to
• High Plains aquifer recharge (shared
• by 8 states critical irrigation source)

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Groundwater Connections

• TX, OK playa lakes are foci for High
• Plains aquifer recharge
• Karst terrains efficient groundwater
• recharge

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Groundwater Connections
Maintain Base Stream Flows

• MN wetlands act as reservoirs that
• regulate stream flows during dry periods
• ND lateral movement of groundwater
• from potholes to flowing stream 27 km
• away
• High Plains aquifer discharges into
• Platte, Republican, and Arkansas Rivers

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Platte and South Platte Rivers
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South Platte River, Colorado
Wetland basin
South Platte River
One Mile

• Significant nexus?
• Intrastate, geographically isolated?

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Tamarack Project
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At High River Stages Winter/Spring
Wetland recharge basin
River
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At Low River Stages Summer/Fall
Wetland recharge basin
River
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Adjudicated Recharge Distances/Times

• Brush Prairie Wetlands/Ponds
• 5-7 miles from the river
• 5 years

• Little Bijou Reservoir
• 8 miles from the river
• 4,500 days, i.e., 12 years

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Biological Nexus

• Threatened and endangered species (state
  fed.)

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7,800 basins pre-settlement 374 basins today

• 5-7 million waterfowl use annually
• 90 of mid-continent white-fronted
• geese
• 50 of mid-continent mallards

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Groundwater Connections
12 of tested wells around the country had
harmful levels of at least one pesticide
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Groundwater Connections

• GH Superfund site, Macomb Co., MI,
• (same county as Carabell wetlands)
• 100-acre site geog. isolated
• Waste oil reclamation facility
• Contaminated surface water,
• ground water, soils
• VOCs detected in nearby wells
• Fish in nearby Clinton River
• contaminated

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Water Quality Maintenance
Positive impact on water quality by trapping,
precipitating, transforming, recycling and/or
exporting chemical and other waterborne
constituents
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Water Quality Maintenance
Water filtering through Delmarva bays to
Ches- apeake Bay has lower N than water
circumvented through drainage canals
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Water Quality Maintenance

• Higher playa lake water quality relative
• to water entering the wetlands
• Playas improve High Plains
• groundwater, flowing waters into which
• aquifer discharges

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Water Quality Maintenance

• CA wetlands removed an average of
• 69 of the selenium in agricultural
• runoff
• FL changes in chemistry of GI wetlands
• easily transported and reflected in
• quality of groundwater
• Increased flood flows (associated with
• loss of wetlands in watershed)
• increases streambank erosion and
• sediment loads

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Wetland Functions
Waterfowl and fish and wildlife habitat
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• 1.6 million waterfowl hunters in U.S.
• 15 million hunter-days afield

Waterfowl Hunting Economics

• 935 million total expenditures
• 2.3 billion total economic output
• 21,415 jobs
• 725 million in employment income
• 130 in state tax revenue
• 202 million in federal tax revenue

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20 million waterfowl and shorebird viewers in
U.S. Total economic output of 9.8 billion1
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Ecological Linkages and Interstate Commerce

• Migratory Waterfowl
• 1,589,000 duck hunters in 2001
• 17.5 hunted out-of-state

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Ecological Linkages

• Migratory Waterfowl
• 56 of all banded waterfowl are
• recovered outside the political
• jurisdiction of banding
• Michigan
• 57 outside MI 11 outside U.S.

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Ecological Linkages

• Migratory Waterfowl
• Prairie Pothole States of ND, SD, MT
• 73 outside the states
• 9.4 outside the U.S.

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Ecological Linkages and Interstate Commerce

• Migratory Waterfowl
• NOT just wetlands
• IL largest number of wood ducks
• associated with smallest streams
• NE adults and broods on many
• unfloatable streams

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Science.
in fulfillment of the purpose of the Clean Water
Act must be the foundation for jurisdiction
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Thank you for your time!