REGULATORY PLANNING FOR
NEBRASKA'S RAINWATER BASIN WETLANDS
ADVANCED IDENTIFICATION OF DISPOSAL AREAS
by
U. S. Evironmental Protection Agency
Region VII
Kansas City, Kansas
U. S. Fish and Wildlife Service
Grand Island, Nebraska
Denver, Colorado
U. S. Army Engineer District, Omaha
Corps of Engineers
Omaha, Nebraska
Nebraska Game and Parks Commission
Lincoln, Nebraska
October 1990
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Regulatory Planning for Nebraska's Rainwater Basin Wetlands
(Advanced Identification of Disposal Areas)
A Cooperative Effort
by
U.S. Environmental Protection Agency
Region VII
Kansas City, Kansas i
U.S. Army Engineer District, Omaha
Corps of Engineers
Omaha, Nebraska
U.S. Fish and Wildlife Service
Grand Island, Nebraska
Denver, Colorado
Nebraska Game and Parks Comnission
Lincoln, Nebraska
October 1990
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This report should be cited as follows:
Raines, Richard R., M.C. Gilbert, R.A. Gersib, W.S. Rosier, and K.F.
Dinan. 1990. Regulatory planning for Nebraska's Rainwater Basin wet-
lands (Advanced Identification of Disposal Areas). Prepared for the
Rainwater Basin Advanced Identification Study. U.S. Environmental
Protection Agency, Region VII, Kansas City, Kansas and U.S. Army
Engineer District, Omaha, Omaha, Nebraska. 46 pp. plus appendices.
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FOREWORD
In 1986, the U.S. Environmental Protection Agency (EPA) initiated
an Advanced Identification of Disposal Areas program (40 CFR § 230.80)
for the Rainwater Basin wetlands complex in southcentral Nebraska. EPA,
working jointly with the U.S. Army Corps of Engineers, the U.S. Fish and
Wildlife Service, and the Nebraska Game and Parks Commission, with
assistance from the Nebraska Department of Environmental Control and the
USDA Soil Conservation Service, established five objectives: (1) desig-
nate wetlands potentially regulated under Section 404 of the Clean Water
Act and those that may be suitable or unsuitable for fill under the
review requirements contained in EPA's Section 404(b)(l) Guidelines;
(2) increase the wetland information data base to support future
regulatory policy and wetlands management initiatives; (3) collect
information necessary for making wetlands jurisdictional and delineation
determinations; (4) increase public awareness of the Section 404 permit
process; and (5) increase public awareness of wetland values/functions.
This report provides the basis for site designations under the
Advanced Identification of Disposal Areas program. The first part of
this report provides a discussion of project purpose and need based upon
a review of resource literature and prior administration of the Section
404 program. An overview of technical studies conducted in response to
public and interagency scoping efforts also is provided. Results of the
technical studies conducted (including economic assessment, waterfowl
studies, functional assessment evaluation, and vegetation/mapping stud-
ies) are presented. These studies were conducted to provide a rationale
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for designation in consideration of both potential Corps of Engineers'
jurisdiction and documented wetland values/functions. Results of these
studies are integrated into the last part of this document for advanced
identification determinations. The view of the participating agencies
on categories of discharges (activities) and options for future Section
404 program administration and wetland protection in the Rainwater Basin
also are provided.
Morris'Kay, Regional Administrator
U.S. Environmental Protection Agency
Region VII
/Donald E. Ha^rT
Colonel, Corns j/f Engineers
District Engft
JOHN L SPINKS-JR<
Gal en/L. Buterbaughr
al Director
U.S. Fish and Wildlife Service
Region 6
W. Rex Amack
Director
Nebraska Game and Parks
Commission
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EXECUTIVE SUMMARY
The Rainwater Basin is an area covering parts of 17 counties and
some 4,200 square miles south of the Platte River in central Nebraska.
In 1986 the Environmental Protection Agency (EPA) and the Corps of
Engineers initiated the Rainwater Basin Advanced Identification Study.
The public was informed that the study would identify wetlands poten-
tially regulated under Section 404 of the Clean Water Act and designate
those that may be suitable or unsuitable for fill based upon the review
requirements contained in the Section 404(b)(l) Guidelines.
The technical rationale for considering designation of disposal
areas (sites) as generally suitable or unsuitable for fill was based on
the findings of the supporting technical appendices and analysis
presented in this report. Major study findings are outlined as follows:
1. Most Rainwater Basin wetlands are subject to the Section 404
provisions of the Clean Water ,Act.
2. All Rainwater Basin wetlands have HIGH values for waterfowl
use.
3. All Rainwater Basin wetlands have the potential to provide HIGH
functional values.
To apply study findings to site designations, U.S. Fish and
Wildlife Service National Wetlands Inventory data were utilized. A
total of 54,630 acres of wetlands were identified within the study area
boundaries.
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Of these wetlands, a total of 34,103 acres of Palustrine
System wetlands were identified as the "traditional depressional
rainwater basins." These wetlands were subsequently identified as Class
I wetlands. The remaining Palustrine. System wetlands were examined to
determine if important similar or support functions to the "traditional
depressional rainwater basins" were potentially being provided. A total
of 3,125 acres of these areas were identified and grouped into the
category Class II wetlands. All remaining wetlands of the Palustrine,
Riverine, and Lacustrine Systems were identified as Class III wetlands,
totaling 17,402 acres. These wetlands were viewed as providing impor-
tant functional values, but not in a similar capacity as the Class I and
II categories.
The wetlands exhibiting or potentially providing the highest degree
of value were viewed as areas where the discharge of dredged or fill
material would not likely be in compliance with the Section 404(b)(l)
Guidelines (Class I and Class II wetlands). For Class III wetlands,
compliance with the Section 404(b)(l) Guidelines was recommended to be
determined on a case-by-case basis pending a review of functional value
impacts. Based on the conclusions of the technical appendices, analyses
presented in this report, and review of mapping data, the following
designations were recommended:
Class I
Wetlands generally unsuitable for fill based on docu-
mented high functional values (traditional depressional
rainwater basins).
Class II
Wetlands generally unsuitable for fill based upon
the probability of providing high functional values
(other Palustrine System wetland types providing
similar or supportive functions as Class I wetlands).
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Class III
Wetlands generally subject to Department of the Army
permitting requirements (all remaining Palustrine,
Riverine, and Lacustrine System wetlands not contained
in Classes I and II). Evaluated on a case-by-case basis
for suitability determinations.
To supplement the Class designations, a review of fill activities
potentially affecting the regional resource was conducted. High, moder-
ate and low probability ratings of compliance with the Section 404(b)(l)
Guidelines were assigned for common categories of discharge. A high
probability of compliance for an activity was considered as suitable for
disposal of dredged or fill material in Class I and Class II wetlands.
Moderate or a low probability of compliance for an activity was consid-
ered as generally unsuitable for fill in all Class I and Class II wet-
lands. Activities affecting Class III wetlands were recommended to
be evaluated on a case-by-case basis for suitability and compliance
determinations.
Post-Advanced Identifiation Study options were identified for
future Section 404 program administration. Protection options address
areas of wetland regulation, acquisition, management and enhancement,
public outreach, and identification of information needs.
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TABLE OF CONTENTS
Page
FOREWORD
EXECUTIVE SUMMARY i
FIGURES vi
TABLES vi i
ACKNOWLEDGEMENTS vi i i
INTRODUCTION -. 1
PURPOSE AND NEED 1
Resource Background 1
Regulatory Background 4
Economic Considerations 8
Ecological Considerations 9
RESOURCE CHARACTERIZATION 10
METHODS 13
STUDY SITE SELECTION AND GENERAL METHODOLOGY 13
VALUE-BASED ASSESSMENT ,. 16
Waterfowl Values 16
Wet!and Functi ons 17
JURISDICTIONAL ASSESSMENT 17
Mapping Data 18
Vegetati on Data 18
RESULTS AND DISCUSSION 20
VALUE-BASED ASSESSMENT 20
Waterfowl Values 20
Wetland Functi ons 25
JURISDICTIONAL ASSESSMENT 28
Mapping Data 28
Vegetation Data 29
CONCLUSIONS 32
RECOMMENDATIONS 34
RATIONALE FOR DESIGNATION 34
RECOMMENDED DESIGNATION 37
CATEGORIES OF DISCHARGE (ACTIVITIES) 37
OPTIONS FOR FUTURE WETLAND PROTECTION 40
Regul ati on 41
Wetland Management 42
Pub!ic Outreach 42
Informati on Needs 43
LITERATURE CITED 44
APPENDICES v
IV
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APPENDICES
A. The Profitability of Wetland Drainage in the Rainwater
Basin of Nebraska (Swanson 1986).
B. Waterfowl Values by Wetland, Type within Rainwater Basin
Wetlands with Special Emphasis on Activity Time Budget
and Census Data (Gersib et al. 1989a).
C. A Functional Assessment of Selected Wetlands within the
Rainwater Basin Area of Nebraska (Gersib et al, 1989b).
D. Ordination and Mapping of Wetland Communities in Nebraska's
Rainwater Basin Region (Gilbert 1989).
E. Rainwater Basin Wetland Map Atlas (U.S. Environmental Protection
Agency 1990).
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FIGURES
Page
1. Nebraska's Rainwater Basin wetland region 2
2. Rainwater Basin Advanced Identification of Disposal Areas
Study boundaries 11
VI
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TABLES
Page
1. Profitability of wetland conversion 9
2. Rainwater Basin wetland study sites by county 14
3. Waterfowl values for individual study sites 21
4. Overall waterfowl value , '. 23
5. Wetland functional values ! 26
6. Overall wetland functional values 27
7. Intersection of Cowardin et al,; (1979) water regimes with
hydric/non-hydric soils 28
8. Assessment of vegetation, soils, and hydrology criteria from
survey data 29
9. Summary of technical analyses and potential future threats to
Rainwater Basin wetlands : '.. 33
10. Class I, II, and III wetland acreages for the Rainwater Basin
Advanced Identification Study.. 35
11. General probabilities of compliance with the Section 404(b)(l)
Guidelines for common discharge activities in the Rainwater
Basin region 39
vn
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ACKNOWLEDGEMENTS
The authors wish to recognize the Rainwater Basin Advanced
Identification technical work team members, past and present, who iden-
tified a need and then committed the time to ensure project completion.
The efforts and dedication of J. Brabander, B. Elder, F. Furst, T. Hupf,
J. Klott, and J.G. Yager are sincerely appreciated. Special recognition
to C. Elliott for his significant input and assistance throughout this
study. A special thank you goes to V. Hale and other staff of the U.S.
Environmental Protection Agency, Office of Integrated Environmental
Analysis, for their assistance in providing data and preparing the maps
for Appendix E of this report. We wish to thank the many reviewers of
this document for their contributions.
Funding and/or personnel time for the preparation of this report
was provided by the U.S. Environmental Protection Agency, U.S. Army
Corps of Engineers, Omaha District, Nebraska Game and Parks Commission,
and the U.S. Fish and Wildlife Service.
vm
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INTRODUCTION
PURPOSE AND NEED
Resource Background ...:..
The conversion of wetlands to agricultural land is the major
factor contributing to wetland loss and degradation in the United States
(Tiner 1984). In few other areas is this loss more apparent than in the
Rainwater Basin of Nebraska (The Conservation Foundation 1988).
The Rainwater Basin is an area covering parts of 17 counties and
some 4,200 square miles south of the Platte River in central Nebraska
(Figure 1). Wetlands range in size from less than one acre to over
1,000 acres. Soil survey maps from early in this century indicated that
the Rainwater Basin area once contained nearly 4,000 individually iden-
tified wetland basins totaling 94,000 acres. Nebraska Game and Parks
Commission (1984) estimates indicated that less than 10 percent (approx-
imately 375) of these original mapped wetland basins and 22 percent of
their acreage (20,000 acres) remained. Over 10,000 acres are owned and
managed by State or Federal wildlife agencies.
Destruction of the Rainwater Basin wetlands began in the early
1900's but proceeded slowly because of inadequate technology and
equipment. Following World War II, as earth-moving equipment became
available, wetland destruction rapidly accelerated. The primary objec-
tives of wetland conversions have either been to gain additional agri-
cultural land or to achieve more efficient farming practices by elimi-
nating wetlands interfering with irrigation systems. Nearly 90 percent
of this wetland destruction was accomplished by combining drainage
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ditches with deepened roadside ditches or dugouts (Nebraska Game and
Parks Commission 1984). Depositing excavated material from the dugouts
further degraded the wetlands. Land leveling associated with gravity
irrigation and dugout construction has accounted for additional destruc-
tion. Since the 1960's, economic conditions have spurred agricultural
intensification and deep well irrigation in south-central Nebraska
(Swanson 1986). During this time, drainage ditches, dugouts and associ-
ated filling activities have accounted for the vast majority of wetland
losses. Wetland degradation also has resulted from upland farming
practices which have accelerated basin siltation. In recent years,
wetland conversion to cropland has been strongly correlated with natural
dry cycles in the Rainwater Basin area (Nebraska Game and Parks Commis-
sion 1984; U.S. Fish and Wildlife Service and Nebraska Game and Parks
Commission 1986).
A major implication of wetland destruction is the loss of wildlife
habitat for millions of waterfowl and other wildlife that use the Rain-
water Basin area. This wetland complex serves as essential waterfowl
spring staging habitat for five to seven million waterfowl. Waterfowl
utilize this area for courtship, for pair formation, and most signifi-
cantly as spring staging habitat where birds buildup fat reserves needed
for the remaining migration and successful initiation of nesting on
northern production grounds. Over 92 species of birds are' known to
breed and rear offspring in the Rainwater Basin with ducks alone produc-
ing over 10,000 young to flight stage in an average water year (U.S.
Fish and Wildlife Service and Nebraska Game and Parks Commission 1986).
The Rainwater Basin area also provides significant values to fall
migrants.
The loss of wetland habitat in the Rainwater Basin area has caused
waterfowl to be crowded into fewer suitable roosting, loafing, and feed-
ing sites during spring migration. This crowding has increased the
susceptibility of these birds to catastrophic losses from natural envi-
ronmental disasters such as severe spring storms, drought, and disease.
Avian cholera outbreaks, which have occurred annually in the Rainwater.
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Basin since 1975 (Schildman and Hurt 1984), are symptomatic of habitat
loss and are now considered to be enzootic to the region (R. Winding-
stad; pers. comm.). Approximately 200,000 ducks and geese died from
avian cholera in the Rainwater Basin between 1975 and 1984 (Schildman
and Hurt 1984). Mortality has been highest for mallards, northern
pintails, greater white-fronted geese and Canada geese. The loss of
greater white-fronted geese is of special concern as nearly the entire
mid-continent population stages in the Rainwater Basin area each spring
(Benning 1987). In 1980, five percent of this population died from
avian cholera. Mallard and northern pintail mortality is also of
concern because of their declining populations in the Central Flyway.
This wetland area also serves as important migration habitat for
endangered species and other migratory water birds. The Rainwater Basin
area is recognized as important migration habitat for whooping cranes
and sandhill cranes. Further, geographic location and limited occur-
rence records suggest that the Rainwater Basin area has the potential to
provide migration values for shorebirds and wading birds that approach
the known habitat values provided by waterfowl (Gersib et al. 1990).
This area also provides essential habitat for resident wildlife species
(e.g., pheasant, deer, rabbit).
Regulatory Background
The Department of the Army's regulatory program is one of the
oldest in the Federal government. The initial mission of the program
was to protect the navigational servitude of the Nation's waterways.
Changing public needs, new statutory mandates, and increased stress on
natural resources have changed the complexion of the program. In no
area have the changes been greater or more controversial than in the
regulation of wetlands.
The Federal Water Pollution Control Act Amendments of 1972 added
what is commonly called Section 404 authority (33 U.S.C. 1344) to the
Department of the Army's regulatory program. The Secretary of the Army,
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acting through the Chief of Engineers may issue permits, after notice
and opportunity for public hearings, for the discharge of dredged or
fill material into waters of the United States at specified disposal
sites. The selection of such sites must be in accordance with evalua-
tion criteria developed by the Environmental Protection Agency (EPA) in
conjunction with the Secretary of the Army. These regulations are known
as the Section 404(b)(l) Guidelines (Federal Register 1980).
The Section 404(b)(l) Guidelines (Guidelines) evaluation criteria
contain several provisions which prohibit issuance of a permit for
activities which have avoidable or significant impacts to wetlands. For
"non-water dependent projects", i.e., those that do not need to be
located in or near water to fulfill their basic purpose, the Guidelines
presume that less environmentally damaging practicable alternatives to
filling wetlands exist. The purpose of the "water dependency test" is
to recognize special aquatic sites (i.e., wetlands), and to avoid their
unnecessary destruction, particularly when practicable alternatives are
available in non-aquatic areas to achieve the basic purposes of a
project. The Guidelines also prohibit projects which would jeopardize
the continued existence of a federally threatened or endangered species,
violate State water quality standards, or involve significant environ-
mental degradation. In addition, the Guidelines require that unavoid-
able impacts be mitigated to the maximum extent possible. These Guide-
lines, in effect, provide the standard criteria for evaluation of Clean
Water Act Section 404 permits. In addition to complying with the Guide-
lines, in order for a Clean Water Act Section 404 permit to be issued,
the project must not be contrary to the public interest.
The Corps of Engineers (COE) assumed jurisdiction over isolated
wetlands including many Rainwater Basin wetlands, in 1977 (Federal
Register 1977). The majority of fill activities have included land-use
alteration for irrigation system development, incorporating drainage,
land leveling, and water reuse pit construction. The Omaha District COE
assumed discretionary authority to determine, on a case-by-case basis,
the need for individual Section 404 permit reviews in the Rainwater
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Basin. From 1978 to 1982, there were an estimated forty-five Section
404 activities. In July 1982, significant changes occurred in the
regulatory program relative to evaluating wetland fill activities. A
nationwide permit was issued authorizing discharges of dredged or fill
material into isolated waters (Federal Register 1982). During the
administration of this nationwide permit between 1982 and 1984, filling
of Rainwater Basin wetlands may have accelerated, although no conclusive
data are available.
Additional modifications to the COE permitting process occurred
in October 1984, including a revision of the nationwide permit for
isolated wetlands (Federal Register 1984). Revised regulations defined
criteria to determine whether individual or nationwide permitting was
appropriate for isolated wetlands. Under these revisions, any dis-
charge that would cause the loss or substantial adverse modification of
10 acres or more of wetlands required authorization by an individual
permit. For those fill activities affecting up to 10 acres, predis-
charge notification and interagency review requirements were established
to permit the COE to determine' whether to require an individual permit
for the discharge.
Since 1984, twenty-four Section 404 actions have been evaluated in
the Rainwater Basin. Although the total number of permit actions for
this time period is not inordinate, because of the value of the wetland
resource involved and its comparative scarcity, the number of permit
actions has elicited concern for significant cumulative impacts. These
numbers do not reflect unreported activities or those not requiring
Department of the Army authorization that may ultimately affect wetland
quality or quantity.
Of those activities evaluated under the individual permit
process, few would have been in compliance with the Guidelines unless
mitigation for adverse wetland impacts was provided or wetland enhance-
ment was a project purpose. In some cases however, permit decisions
were affected by conflicting wetland boundary determinations and varying
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opinions of wetland values between the permitting and reviewing
agencies. In other cases, the conversion of wetlands to standing crop-
lands has been so rapid that the presence or absence of a wetland was
difficult to determine. For some Section 404 actions, where mitigation
was required for permit issuance,, fulfillment of mitigation goals or
their success were not always verified.
In lieu of this case-by-case permit review, an opportunity for
more responsive regional regulatory management is found in Subpart I
"Planning to Shorten Permit Processing Time" in the Guidelines, Section
230.80 "Advanced Identification of Disposal Areas." Under this section,
the EPA Regional Administrator and the COE District Engineer may identi-
fy specific areas for advanced identification determinations. This
section establishes general procedures by which advanced identifica-
tions of dredged or fill material disposal sites can be made. The
purpose of advanced identification is to determine the suitability or
unsuitability of a site/area for the future disposal of dredged or fill
material. The specification of any given site/area as either suitable
or unsuitable for discharges of dredged or fill material neither consti-
tutes a permit nor prohibits application for a permit. Either type of
identification constitutes information that can be used to facilitate
individual or general permit application and processing. During this
process, environmental information that is normally reviewed during a
Section 404 permit application is collected and analyzed.
Requirements in the Guidelines state that appropriate public
notice of the identified areas shall be issued and that the permitting
authority shall maintain a public record of all identified areas. A
written statement of the basis for identification is also required. The
following sections provide an overview of technical studies conducted to
develop the basis for advanced identification determinations in the
Rainwater Basin.
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Economic Considerations
Evaluation of existing information regarding causes of wetland
loss and deterioration in the Rainwater Basin confirmed that most wet-
land loss or deterioration was directly related to intensified or
expanded agricultural production (Office of Technology Assessment 1984).
Economic conditions in agriculture provide an opportunity to assess
whether converting Rainwater Basin wetlands to agricultural use has been
in the past, is now, or will be in the future actually a profitable
investment.
A very general economic assessment of profitability was contained
in the Office of Technology Assessment report of 1984. More detailed
Basin specific information was considered necessary to address the
profitability of wetland conversion. An economic study (Swanson 1986)
was completed to gather the data and information necessary to determine
profitability and potential future threats to Rainwater Basin wetlands
(Appendix A). The framework for this analysis was a cash flow model.
The model related production and cash receipts from a wetland conversion
on an annual basis to expenditures between 1980 and 1985. From this
analysis, a determination was made as to the projected profitability of
drainage through 1990 for selected soil and wetland types. This study
concluded that: (1) there has been a general decline in the profitabil-
ity of draining and cropping wetlands in the region; (2) temporarily and
seasonally flooded wetland basins have the greatest vulnerability
from filling/draining activities; and (3) drainage of semipermanently
flooded wetlands has been generally unprofitable in the past and will be
increasingly so in the future. Summarization of profitability and
earthwork requirements for converting wetlands to agricultural produc-
tion is shown in Table 1.
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Table 1. Profitability of wetland conversion (Swanson 1986).
Wetland
Water Regime
Earthwork
Necessary for
Filling Basin3
Profitability
of Drainage
Semipermanently Flooded > 1,600 yd3
Seasonally Flooded
Temporarily Flooded
Not Profitable
800 yd3-1600 yd3 Possibly Profitable
300 yd3-800 yd3
Profitable
aBreak-even point ("profitability":) for 1980-1984 == 1,025 yd3/acre,
1985-1989 = 950 yd3/acre, and 1990 = 812 yd3/acre.
Ecological Considerations
Initial evaluation of existing information regarding Rainwater.
Basin resources confirmed that little ecological data had been collected
in a systematic manner. Wetland inventory data (Nebraska Game and Parks
Commission 1972, 1984) were the primary source of information. Esti-
mates on total waterfowl use and avian cholera deaths since 1975 also
were available from the U.S. Fish and Wildlife Service and the Nebraska
Game and Parks Commission. Only sparse data were available on
vegetation characteristics, wetlands functions, and specific waterfowl
activities during spring migration!
Prior to recent wetland inventory efforts by the U.S. Fish and
Wildlife Service (Service), the most useful data were from the Nebraska
Game and Parks Commission (NGPC) inventories of the 1960's and early
1980's. Wetlands were classified in accordance with Martin et al.
(1953). A purpose of the 1960's survey was to provide baseline informa-
tion regarding Nebraska's wetland areas overlooked by nationwide inven-
tory works conducted in the 1950's (U.S. Department of the Interior
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1954). Wetland inventory work in the early 1980's by the NGPC was
conducted to determine the changes that had occurred during the approxi-
mate 20-year interval since earlier survey efforts.
Such data have been of limited utility from a regulatory stand-
point since detailed vegetational community composition information and
potential non-waterfowl functions were not addressed. These inventories
do, however, provide a significant record of the historic numbers and
distribution of Rainwater Basin wetlands and their general waterfowl
values.
In order to document the potential scientific and environmental
significance of the wetlands in the Rainwater Basin, additional baseline
data were needed. An updated inventory using the Service's National
Wetland Inventory (NWI) conventions was initiated to document wetlands
within^the Rainwater Basin region. Mapping was based on photo interpre-
tation of 1981 aerial photography with wetlands classified according to
Cowardin et al. (1979). The area illustrated in Figure 2 represents
study boundaries for this report. The NWI classified wetlands within
this area constitute the "population" for consideration in the Advanced
Identification program.
RESOURCE CHARACTERIZATION
Maintenance of habitat values for waterfowl and other migratory
birds was recognized as a prime motivating factor for multiagency coop-
erative efforts in 'the Rainwater Basin. In recognition of this resource
need and information derived from interagency/public scoping efforts,
three major technical resource characterization studies were identified.
Documentation of waterfowl use, assessment of wetland functions, and
characterization of Rainwater Basin plant communities were the principal
studies initiated to fulfill the Advanced Identification of Disposal
Areas program requirements. Palustrine System wetlands, comprised of
temporarily flooded, seasonally flooded, and semipermanently flooded
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water regimes, served as the categories of interest for resource
characterization studies.
Information on the diurnal behavior of waterfowl species during
1 /'
spring staging was collected using activity time budget analyses.
Concurrently, census data were obtained to provide estimates on
the numbers of waterfowl using wetlands. These data, in conjunction
with an extensive literature review, are presented in Appendix B to
provide a continental perspective of the Rainwater Basin wetland values
to waterfowl. Application of the Federal Highway Administration func-
tional assessment methodology (Adamus and Stockwell 1983) provided the
opportunity to objectively assess non-waterfowl functions (Appendix C).
Vegetation-soil characteristics were evaluated through field surveys and
mapping of individual study sites (Appendix D). This investigation also
provides descriptive information on species composition and plant
communities.
Extracted results of these studies were applied to the development
of the technical rationale for designation under Section 230.80 of the
Guidelines. Demonstration of Rainwater Basin wetlands as jurisdictional
"waters of the United States" and as areas providing significant values
were determined to be the two criteria necessary for candidacy under the
advanced identification process.
The assumption of jurisdiction under the Section 404 program also
is activity based. Therefore, a "categories of discharge" review was
conducted to address generic types of fill activities. This analysis
was initiated to provide a preliminary determination of compliance of a
proposed discharge with the Guidelines in light of the environmental
data collected. Additionally, this application can be used as an indi-
cation of permit predictability for the affected public and as an oppor-
tunity for procedural modifications within the authorities of the Clean
Water Act.
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METHODS
STUDY SITE SELECTION AND GENERAL METHODOLOGY
Study site selection was based on a stratified-random sample from
NGPC (1984) wetlands inventory data. Wetlands were stratified, propor-
tionate to those remaining, on an east-west distributional basis and by
wetland type (Martin et al. 1953). Agricultural Stabilization and
Conservation Service's aerial photographs, soil surveys, draft NWI
maps1, historic site documentation, and 1986 aerial photography were
reviewed to derive the study sites for investigation. The final deter-
mination of an individual wetland for study was based on the prerogative
of the principal investigator for each of the technical resource inves-
tigations. Sites analyzed and the type of study conducted are provided
in Table 2. A total of fifty-seven study sites were selected for water-
fowl, Adamus, and vegetation/mapping studies. Overlap of all studies at
all sites was not achieved due to the varying site selection criteria
and experimental design requirements for each investigation. Time
allocated for completion of each work component, limited access, and
adverse site conditions at the time of investigation also proved to be
limiting factors. Sufficient sampling overlap was achieved to allow
inference regarding the Rainwater Basin wetland characteristics by
Cowardin et al. (1979) water regimes.
Wetland value assessment data were consolidated by site and water
regime through matrix construction or tabular format for purposes of
-'-Final NWI maps were not available at the time of study site
selection.
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analysis. Wetland mapping and vegetational survey data served as the
basis for evaluating Federal jurisdiction. These data were aggregated
for all study sites and grouped by water regime for analysis.
VALUE-BASED ASSESSMENT
Waterfowl Values
Waterfowl data were considered to be the primary component of the
value-based evaluation process. For this analysis, results were ex-
tracted from project waterfowl studies (Gersib et al. 1989a), known
habitat needs of waterfowl available from the literature, best profes-
sional judgments, and study site characteristics derived from project
mapping. A "determinant" water regime was assigned to each study site
based on mapping data from Gilbert (1989). The determinant regime
accounted for greater than 25 percent of a study sites' area and was
considered to be the water regime most likely to influence waterfowl
use.
A study site's potential to fulfill identified waterfowl needs
was evaluated. High, moderate, or low probability ratings to seasonal
habitat categories were assigned. Seasonal habitat categories used in
this analysis consisted of spring staging, production, and fall migra-
tion. Assignment of ratings was conducted separately for ducks and
geese for spring staging. Functional categories used in this analysis
for spring staging consisted of feeding, loafing, and courtship behav-
ior. The NGPC (1984) inventory data and NWI data were used to assess
each study site's opportunity to function as part of a wetland complex.
In consideration of all seasonal habitat and functional catego-
ries, a site's value to waterfowl was determined. Methodology for this
assignment was consistent with Adamus and Stockwell (1983). These
authors state that if an overall rating must be assigned, the highest
rating should be used. These functional category values were then
consolidated into an overall spring staging value. These data were
16
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further grouped by determinant water regime and seasonal habitat catego-
ry. Finally, an overall value for a water regime was then assigned
based upon the highest rating within each seasonal habitat category.
Wetland Functions
Non-waterfowl functional assessment data were considered to be a
second component of the value-based evaluation process. Data for this
analysis were extracted from the functional assessment portion of this
study, known functional values of Rainwater Basin wetlands available
from the literature, and best professional opinion. The determinant
water regime also was assigned in this analysis for grouping of sites.
Results of the application indicated a composite high probability
that overall wetland functions and values are occurring at each study
site (Gersib et al. 1989b). This 'allowed the analysis of water regimes
by individual functional category (e.g., ground water recharge, sediment
trapping). Functional categories were further consolidated to an analy-
sis of general wetland functions (physical, chemical, biological, and
social significance) for each water regime. An overall value for a
water regime was then assigned based upon the highest rating within
each general wetland functional category.
OURISDICTIONAL ASSESSMENT !
Jurisdictional assessments reflect a reasonable probability that
the temporarily flooded, seasonally flooded, and semipermanently flooded
water regimes are "waters of the United States." Assessment of poten-
tial jurisdiction was based upon vegetation, soils, and hydrology crite-
ria derived from data in Gilbert (1989). Both wetland mapping and
vegetation survey data were used in this application to describe cases
where one, two, or all three criteria of the Federal Manual for Identi-
fying and Delineating Jurisdictional Wetlands (Federal Interagency
Committee for Wetland Delineation 1989) were met. Jurisdictional assess-
ments were not considered to constitute final delineations.
17
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Both mapping and vegetation survey data were summarized by water
regimes and observations where criteria were negative or positive.
These data also provided the opportunity to identify discrepancies
between criteria.
t'
Mapping Data
For wetlands/soils mapping data, the aggregated cross-tabulation
results for 47 study sites were used to evaluate potential jurisdiction.
Cowardin et al. (1979) mapping types intersecting soil mapping units
were grouped to compare water regimes versus non-hydric or hydric soil
series.
In this application, water regimes were treated as positive
indicators for both hydrology and vegetation. Hydric soil series were
considered a positive indicator for the soils criteria. An "upland"
designation was considered as a negative indicator for hydrology and
vegetation. A non-hydric soil mapping unit was considered a negative
indicator for the soils criteria.
Veqetati on Data
Corollary data for jurisdictional assessments were derived from the
vegetation study's survey data sets. The most probable Cowardin et al.
(1979) water regime was assigned to each vegetation sample. Determina-
tion of a water regime assignment was based upon the hydric value2,
percent composition of indicator species, species composition, and the
professional judgments of the interagency work team. A water regime
assignment was considered to be a positive indicator for the hydrology
criteria. A generic designation as upland (U) for a sample was consid-
ered a negative indicator. Water regimes assigned consisted of
*•* *
2A prevalence index utilized prior to the development
and adoption of the Federal. Manual for Identifying and
Delineating Jurisdictional Wetlands (Federal Interagency
Committee for Wetland Delineation 1989).
18
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temporarily flooded, seasonally flooded, and semipermanently flooded. A
positive indicator of soils was based upon USDA Soil Conservation
Service (SCS) hydric soils criteria (U.S. Department of Agriculture
1987). The hydric value was used to determine the vegetation criteria.
These three criteria were summarized in spreadsheet format for each of
272 samples.
19
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RESULTS AND DISCUSSION
Matrices in this section are the result of the Advanced
Identification technical studies, existing literature, and best profes-
sional judgments. The value-based and jurisdictional assessments form
the technical rationale for designation. Complete economic study
results are presented in Appendix A.
VALUE-BASED ASSESSMENT
Waterfowl Values
The results of detailed field studies compared the relative
importance of three Palustrine System emergent wetland types (temporari-
ly, seasonally, and semipermanently flooded) by examining waterfowl
occurrence and use. Activity time budget results are presented in
Appendix B.
Each major wetland type provides unique waterfowl spring
staging, production, and fall migration values. The following
results are from Table 3: (1) most temporarily flooded wetlands pro-
vide HIGH spring staging values, LOW to MODERATE production values, LOW
fall migration values with a HIGH overall site value for waterfowl; (2)
most seasonally flooded wetlands provide MODERATE to HIGH spring stag-
ing, production, and fall migration values with a HIGH overall site
value for waterfowl; and (3) most semipermanently flooded wetlands
provide LOW to HIGH spring staging values, and HIGH production and fall
migration values with a HIGH overall site value for waterfowl.
20
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In an attempt to further simplify the waterfowl site value
results identified above, a summary of water regime by seasonal
habitat category is provided in Table 4. An overall waterfowl value
was assigned corresponding to the highest rating associated with each
water regime. All three wetland water regimes (temporarily, season-
ally, and semipermanently flooded) have an overall HIGH value for
waterfowl. i
Table 4. Overall waterfowl value.
OVERALL WATERFOWL VALUE
.
Seasonal Habitat Category Value
Determinant
Water Regime
Temporarily
Flooded
(A)
Seasonally
Flooded
(C)
Semipermanently
Flooded
(F)
Spring Staging
High
High
High
Production
Moderate
, High
High
Fall
Migration
Low
Moderate
High
High
High
High
Cowardin et al. (1979).
Results summarized in Tables 3 and 4 suggest that each Rainwater
Basin wetland has the potential to provide a broad spectrum of values to
waterfowl. As discussed in Gersib et al. (1989a), the actual values
that each wetland provides are dependent upon the ecological factors and
human activities which dictate vegetative composition and diversity.
23
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The Rainwater Basin wetlands are known to serve as a major water-
fowl spring staging area in North America, providing critical habitat
for five to seven million ducks and geese annually. This wetland area
provides spring staging habitat for 90 percent of the mid-continent
population of greater white-fronted geese, 50 percent of the continental
breeding population of mallards, and 30 percent of the continental
northern pintail breeding population. This wetland area has the poten-
tial to provide all essential food and cover necessary for spring stag-
ing waterfowl. These requirements are met through the availability of
temporarily, seasonally, and semipermanently flooded wetlands along with
waste corn from adjacent agricultural fields.
Each major wetland water regime provides unique waterfowl feeding
and resting values necessary for efficient fat deposition during spring
staging. Temporarily and seasonally flooded wetlands provide higher
feeding values than semipermanently flooded wetlands when water is abun-
dant. However, when precipitation is limited, semipermanents may be the
only wetlands with water to provide food values. Semipermanents provide
greater values for loafing and comfort regardless of water conditions.
Rainwater Basin wetlands function as a dynamic system. Changes in
vegetative character and the resulting change in functional values in
response to natural hydrologic cycles, result in an integrated system
that functions as a continuum. This continuum insures 'a broad range of
wetland types without regard to wet or dry cycles, further supporting
the need for protection of all water regimes to maintain functional
values. The high overall value of each wetland water regime (Table 4)
reflects these unique spring staging, production, and fall migration
values. The loss or accelerated degradation of any one of the three
water regimes would break this continuum and reduce the overall values
of the entire wetland complex.
24
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Wetland Functions :
Detailed functional assessment ratings and results for the 20
study sites are presented in Appendix C. This study showed that
Rainwater Basin wetlands appear to have functional ratings that are
generally consistent for all study sites regardless of size, vegetation
type, and hydroperiod.
Results for this application are summarized by water regime in
-Table 5. The following results can be drawn: (1) nearly all water
regimes of Rainwater Basin wetlands can be expected to have a HIGH
probability of providing flood storage, shoreline anchoring, sediment
trapping, nutrient retention — long-term and seasonal, food chain
support--in-basin, wildlife habitat, active recreation, and passive
recreation and heritage values; (2) some Rainwater Basin temporarily
flooded wetlands can be expected to have a MODERATE probability of
providing active recreation, and passive recreation and heritage values;
and (3) nearly all water regimes of Rainwater Basin wetlands can be
expected to have a LOW probability of providing groundwater recharge,
groundwater discharge, food chain support—downstream, and warmwater
fishery habitat values.
To further simplify the results identified above, a summary by
water regime is provided in Table 6. General wetland functions/values,
represented by physical, chemical, biological, and social components,
are presented. An overall wetland functional value rating was assigned
corresponding to the highest rating associated with the value of inter-
est. All three wetland water regimes have an overall HIGH value for
wetland functions.
These functional assessment results, the consistency of results
documented by Gersib et al. (1989b), and the consistency shown in
Table 5, provided the opportunity to more reliably expand the wetland
functional assessment to all Rainwater Basin wetlands.
25
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I
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|
Passive |
Recreation |
and Heritage |
1 1
Active
Recreation
1 1
£ -
11
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5 Is
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Food Chain
Support
Downstream
il|
3 W W
SC DC CO
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Anchoring
t>
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Groundwater
Discharge
Groundwater
Recharge
1 1
Determinant
Water Regine8
x
i = =
-
_i _i -i
=
_i -i -i
=
3= = a=
= =c z
= =c =e
=
_i -j -i
_I —I — *
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26
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Table 6. Overall wetland functional values.
Overall Wetland Functional Value
Determinant
Water Regime8
Temporari ly
Flooded
(A)
Seasonally
Flooded
(C)
Semipermanently
Flooded
(F)
Physical
High
High
High
Chemical
High
High
High
;
Biological
.
High
High
High
1
Social
Moderate
High
High
High
High
High
Cowardin et al. (1979).
The Adamus and Stockwell (1983) wetland evaluation procedure was
designed to objectively assess potential wetland functional values based
on simple physical, chemical and biological indicators along with socio-
economic trends. The methodology was originally intended to measure the
potential impacts of highways upon the functional values of wetlands and
to aide in the mitigation of lost wetland values. The application of
this methodology was expanded by Odum et al. (1986) and Jensen (1987) to
support enhanced wetland protection measures. The use of this methodol-
ogy within Nebraska's Rainwater Basin wetlands extends this application
further.by aiding in the general characterization of the overall values
provided by this wetland complex.
27
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JURISDICTIONAL ASSESSMENT
Complete study results providing basic information on species
compositions and associations, vegetation/soils relationships, and
wetland community characteristics are presented in Appendix D. Results
presented in this section are derived from Gilbert (1989), and evaluated
criteria of vegetation, soils, and hydrology from both mapping and
vegetational survey data.
Mapping Data
Summary results on the intersection of water regimes with soils
data are presented in Table 7. These data indicate the following: (1)
83 percent of the temporarily flooded wetlands occurred on hydric soils;
(2) 90 percent of the seasonally flooded wetlands occurred on hydric
soils; (3) 95 percent of the semipermanently flooded wetlands occurred
on hydric soils; and (4) for all data, 89 percent of the wetlands mapped
occurred on hydric soils; 11 percent of the wetlands occurred on non-
hydric soils.
Table 7. Intersection of Cowardin et at. (1979) water regimes with hydric/non-hydric
soils (mapping data only).
WATER REGIME
Temporarily
Flooded (A)
Seasonally
Flooded (C)
Semipermanently
Flooded (F)
Totals
HYDRIC SOILS
Acres Percent
1210.19 83
1796.18 90
1180.08 95
4186.45 89
SOILS DATA
HON-HYDRIC SOILS
Acres Percent
247.60 17
.
203.22 10
57.10 5
507.92 11
TOTALS
Acres Percent
1457.79 100
1999.40 100
1237.18 100
4694.37 100
28
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Vegetation Data -', •
Results of the jurisdictional assessment conducted for the vegeta-
tional survey data are presented in Table 8. Similar to the mapping
data, cases where all three or less than three of the criteria were met
are presented.
Table 8. Assessment of vegetation, soils, and hydrology criteria from survey data
.
VEGETATION/SOILS INDICATORS
HYDROLOGY
INDICATOR:
-Upland
(n=65)
+Temporarily
Flooded
(n=65)
+Seasonally
Flooded
(n=97)
+Semi -
permanently
Flooded
-------
for both vegetation and soils; (b) 15 percent of the samples have a
positive indicator for vegetation and a negative indicator for soils;
and (c) 2 percent have a positive indicator for soils, but not vegeta-
tion.
(3) All seasonally and semipermanently flooded samples (positive
indicators for hydrology) have positive indicators for both vegetation
and soils.
Mapping data from Gilbert (1989) indicates a highly disturbed
environment based upon the common occurrence of Cowardin et al. (1979)
modifiers describing hydrologic alterations, the calculated Correspond-
ence Index, the large percentage of uplands on hydric soils, and the
occurrence of wetland types on non-hydric soils. Additionally, although
vegetation survey results indicated wetland status for Fill more, Scott,
and Massie soils, the large percentage of uplands associated with the
former two series determined from mapping data would indicate caution
in generalizing wetland-hydric soil relationships in Rainwater Basin
wetlands.
The mapping data used in the jurisdictional assessment study does
not reflect the large percentage of hydric soils not supporting
Cowardin et al. (1979) wetland types. It is estimated that 33 percent
of the hydric soils within the mapping data base do not support wet-
lands. Nonetheless, a high percentage of all water regimes meet all
three criteria.
This analysis only addresses hydric soils associated with existing
wetlands. Sampling design for vegetation/mapping studies did not (and
could not) account for large areas of hydric soils currently incapable
of supporting hydrophytic vegetation-due to hydrological modifications,
filling or land-use practices (historic wetlands).
Gilbert (1989) suggested that low vegetation/soil correlations
may indicate more reliance on vegetation for wetland delineation pur-
poses. He also cautioned that a one-time delineation does not account
30
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for wetland dynamics. Delineations of Rainwater Basin wetlands within
the framework of the Federal Manual for Identifying and Delineating
Jurisdictional Wetlands (Federal Interagency Committee for Wetland
Delineation 1989) would require consideration of successional changes,
vegetation response to disturbance or varying wet-dry cycles. Integra-
tion of existing inventories (Nebraska Game and Parks Commission 1972,
1984; NWI data; and SCS soils and wetlands data), archives of historical
aerial photography, and long-term monitoring are required to support
wetland delineations in future program applications.
31
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CONCLUSIONS
A major goal of the Advanced Identification study was to
identify and protect wetlands, with a strong emphasis on identification
of the most valuable and vulnerable tracts. This report was developed
to document the probability of jurisdiction and to document wetland
functions and values. The following statements summarize the preceding
analyses.
1. Most Rainwater Basin wetlands were determined to be subject to the
provisions of the Clean Water Act.
2. All Rainwater Basin wetlands have HIGH values for waterfowl use.
3. All Rainwater Basin wetlands have the potential to provide HIGH
functional values (e.g., flood storage, sediment trapping, food
chain support—in basin).
Swanson (1986) examined economics to determine existing or future
threats. His analysis suggests that most temporarily and some seasonal-
ly flooded wetlands are still susceptible to conversion. A summary of
technical analyses and economic considerations for future program
management are presented in Table 9.
32
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Table 9. Summary of technical analyses and potential future threats to Rainwater Basin wetlands.
Determinant
Water Regime
Temporarily
Flooded
(A)
Seasonally
Flooded
(C)
Semipermanently
Flooded
(F)
I
Probability
of Meeting All
Three Wetland
Criteria3
Moderate
High
High
1 :
Overall
Waterfowl Value
]
High
High .
High
I . .
Overall
Functional Value
High
High
High
1
Profitability
of
Future
Conversions
High
Moderate
Low
Probability of meeting all three criteria of hydrophytic vegetation, hydric soils, and wetland
hydrology (growing season conditions-average year).
Break-even point ("profitability") for 1990 = 812 yd3/acre (Swanson 1986).
33
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RECOMMENDATIONS
RATIONALE FOR DESIGNATION
Implications of resource characterization findings to the Advanced
Identification process and Section 404 program administration can best
be evaluated while viewing the ecoregion as a whole. NWI mapping pro-
vided the opportunity to apply these study results. NWI digital tape
data were transferred to the EPA Region VII Office of Integrated
Environmental Assessment (OIEA) for conversion and incorporation into
the Region's Geographical Information System (GIS) database. The GIS
database then was used to generate customized wetland maps (Appendix
E). One-hundred nine (109) 7.5 minute USGS quadrangles are contained
within the study boundaries (see Figure 2). A total of 54,630 acres of
wetlands were identified within these boundaries.
To define "traditional depressional rainwater basin" Palustrine
System wetlands, the interagency work group team overlaid the wetland
maps onto SCS soil survey maps. Each individual Palustrine System
polygon occurring on Butler, Fillmore, Massie, Olbut, and Scott depres-
sional soil units was recorded. This set of wetlands, totaling 34,103
acres, were classified as the "traditional depressional rainwater basin"
wetlands. These wetlands were grouped into a category identified as
Class I wetlands to distinguish them from other Palustrine System wet-
lands.
Discrepancies between earlier estimates of wetland numbers
and acreage and those in this report are apparent. The NGPC (1972)
inventory data documented 3,907 wetlands and 94,060 wetland acres based
on hydric soils identified from original U.S. Department of Agriculture
34
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soil survey maps of the early 1900's. Updated soil surveys in the
1960's through 1980's identified significantly more hydric soil acres
than originally identified, resulting in NGPC data underestimating the
total population and acres of wetlands (Nebraska Game and Parks Commis-
sion 1984). Further, the Cowardin et al. (1979) classification system
and NWI mapping conventions allow the identification of wetlands based
on soil signature even though tillage operations may periodically
destroy the dominance of wetland plants. These wetland basins were also
likely not included in earlier inventory efforts (Nebraska Game and
Parks Commission (1984), but are reflected in the Class I category.
Trend analysis data developed during NGPC surveys in the 1960's and
1980's are still considered accurate however, whether based on a survey
of the total wetland population as originally thought, or on a large
sample of the total population of wetlands as is known today.
i
Other Palustrine System polygons not occurring on the identified
depressional soil units were also reviewed. These polygons, categorized
as Class II wetlands, were viewed as potentially providing important or
similar support functions as Class I wetlands due to similarities in
water permanence and vegetation composition. The identification of
these wetlands in addition to the "traditional depressional rainwater
basin" wetlands was based on field experience and professional judgments
of the interagency work team. A total of 3,125 acres were identified
and grouped into the Class II wetlands category. This acreage data does
not necessarily reflect individual basins, but rather specific Cowardin
et al. (1979) wetland types.
All remaining Palustrine, Riverine, and Lacustrine System wetlands
were grouped into a category identified as Class III wetlands (17,402
acres). These wetlands were viewed as potentially providing important
values but not in a similar capacity as Class I and II wetlands. Acre-
age figures for all Classes are summarized by system and water regime in
Table 10. Appendix E provides a summary of Class acreage data by
individual Cowardin et al. (1979) wetland types and additional discus-
sion of methodology.
35
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The wetland habitats exhibiting the highest degree of value,
primarily for waterfowl, were determined to be areas where the discharge
of dredged or fill material would not likely be in compliance with the
Guidelines (Class I wetlands). Wetlands that potentially provide impor-
tant functions also were viewed as generally unsuitable for dredged
or fill activities from the standpoint of significant environmental
degradation that would be caused by the loss of, or degradation to,
habitat (Class II wetlands). Wetlands not identified as exhibiting
the highest degree of value or providing similar or support functions
were still viewed as being important, but were unclassified as to the
probability of compliance with the Guidelines (Class III wetlands).
RECOMMENDED DESIGNATION
Based on the conclusions of the technical appendices, analyses
presented in this report, and wetlands mapping data, the following
designations are recommended:
Class I
Wetlands generally unsuitable for fill based on documented high
functional values (traditional depressional rainwater basins).
Class II
Wetlands generally unsuitable for fill based upon the probability
of providing high functional values (other Palustrine System wetland
types providing similar or supportive functions as Class I wetlands).
Class III
Wetlands generally subject to Department of the Army permitting
requirements (all remaining Palustrine, Riverine and Lacustrine System
wetlands not contained in Classes I and II). Evaluated on a case-by-
case basis for suitability determinations.
CATEGORIES OF DISCHARGE (ACTIVITIES)
As the assumption of Section 404 jurisdiction is two-part; estab-
lishing "waters of the United States" and an activity requiring Depart-
ment of the Army authorization, a categories of discharge review was
37
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conducted to supplement the Class designations. Table 11 presents the
views of regulatory and review agencies that participated in this study
regarding the acceptability of identified categories of discharge/activ-
ities as generally suitable/unsuitable for the disposal of dredged or
fill material into wetlands of the Rainwater Basin. The identified
activities and those requiring multiple project features will be
critically reviewed for the project purpose, alternatives available,
methods of construction, and impacts to wetlands for a final determina-
tion of compliance with the Guidelines.
Based upon the views presented, categories of discharge/activities
with HIGH probabilities of compliance with the Guidelines will be
considered as generally suitable for the disposal of dredged or fill
material into Class I and II wetlands in the Rainwater Basin.
All other categories of discharge/activities evaluated in this
report (MODERATE and LOW), are designated as generally unsuitable for
the disposal of dredged or fill material in all Class I and II wetlands.
A discharge activity receiving a MODERATE rating indicates that the
final determination of compliance depends on the purpose of the project
or construction methods. For example, if the purpose of a water control
structure or diking is for wetland enhancement/restoration, then it
would likely receive a HIGH rating. If the purpose is to redirect water
away from the wetland, then the activity would likely receive a LOW
rating. Other factors influencing a final determination would include a
sites' determinant water regime and the relationship of the disposal
site to the surrounding wetlands complex. Class III wetlands in the
Rainwater Basin area will be evaluated on a case-by-case basis for
functional value impacts.
For the categories of discharge/activities in Table 11, the
following general criteria will be considered to facilitate future
permit decisions.
38
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I
Table 11. General probabilities of compliance with the Section
404(b)(l) Guidelines for common discharge activities
in the Rainwater Basin region.3
HIGH probability of compliance
Wetland restoration/enhancement :
Repair, rehabilitation, replacement of previously authorized
structures
Survey activities
Return water from an upland contained dredged disposal area
Oil and hazardous substances cleanup
MODERATE probability of compliance
Center pivot wheel tracks
Water control structures/earthen plugs
Diking
Duck blinds
Loafing/nesting islands
Outfall/intake structures
Backfill, bedding for utility lines, outfall/intake structures
Bank stabilization
Road crossings !
Bridges
LOW probability of compliance
Stockponds
Water reuse pits
Water concentration pits
Dugouts i
Land leveling ;
Ditching
Channelization
aSee text for examples and further clarification on probabilities
of compliance.
39
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a. Minor water dependent discharge activities are generally
suitable pending demonstration of minimal impacts to affected wetland
Classes and compliance with the Guidelines.
b. Non-water dependent activities are generally unsuitable.
Non-water dependent discharges are those associated with activities
which do not require access or proximity to or siting within a special
aquatic site to fulfill their basic purpose. Practicable alternatives
that do not involve special aquatic sites are presumed to be available,
unless clearly demonstrated otherwise.
c. Proponents of an activity, which would have an impact on
wetland values and functions, will be required to comply with the
Guidelines and other program directives so that "no overall net loss of
wetlands" will be achieved in the Rainwater Basin ecoregion.
d. Fill associated with wetland enhancement/restoration projects
which improve the primary functions and values of these wetlands
will generally receive favorable consideration (e.g., water control
structures, diking).
OPTIONS FOR FUTURE WETLAND PROTECTION
The interagency work group team identified the following list of
options for consideration following completion of the Advanced Identifi-
cation Study for protection, restoration, and preservation of the
remaining wetland 'resources in the Rainwater Basin of Nebraska. The
options presented are not an exhaustive list, but summarize the more
important options for consideration for future Section 404 program
administration. The agencies involved with the Advanced Identification
Study will consider and prioritize these options for possible implemen-
tation.
40
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Regulation
- Development of an administrative procedures document/agreement to
implement the findings of the Advanced Identification Study and
to describe how future permit application reviews will be processed
in the Rainwater Basin.
- Development of standardized review criteria to be used in permit
application acceptance, review, impact analysis, permit issuance/
denial, and site inspections for permit compliance.
- Development of General Permits for certain types of minor discharges
and wetland enhancement/restoration activities.
Evaluation of nationwide permits to determine whether they should
be revised, modified, or even rescinded.
- Maintainence of a joint agency team approach to field evalua-
tion, permit review, and enforcement activities.
Development and implementation of a monitoring program to ensure
that mitigation requirements of Section 404 permits adequately
replace Rainwater Basin wetland functions and values.
- Determine the feasibility of prohibiting the specification or use
of Rainwater Basin wetlands as disposal sites under Section 404(c)
of the Clean Water Act and develop criteria for assumption of
"Special Cases" in light of vegetation study results.
- Improvements in the system for detection of illegal wetland
fill activities which fall under Federal jurisdiction by establish-
ing an annual aerial photo reconnaissance of Rainwater Basin wet-
lands and by encouraging public reporting of apparent illegal fill
activities.
41
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Enforcement of appropriate laws regulating activities in wetlands to
encourage compliance with these laws.
Wetland Management
- Additional acquisition and management of Rainwater Basin wetlands by
Federal, State, and private agencies/organizations.
Provision of support for the implementation of the Rainwater Basin
Joint Venture Project under the North American Waterfowl Management
Plan by promoting information exchange and mutual technical assis-
tance between Federal, State, and local agencies involved in wet-
lands regulation, protection, and enhancement.
Establishment of a program to acknowledge private individuals,
organizations, and corporations that demonstrate leadership in the
protection, enhancement, or restoration of Rainwater Basin wetlands.
- Development of a private lands extension program that provides
technical and financial assistance to landowners who wish to consid-
er enhancement or restoration of Rainwater Basin wetlands.
Public Outreach
- Development of additional programs or publications to increase
public awareness and appreciation of the value of Rainwater Basin
wetlands.
- Distribution of customized wetland maps and information that identi-
fy and describe the Rainwater Basin wetlands to private landowners,
developers, civic organizations and government agencies so they can
avoid inadvertent destruction of wetlands by improper development.
These materials could be distributed through the Agricultural Stabi-
lization and Conservation Service, USDA Soil Conservation Service,
42
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Nebraska Natural Resource Districts, U.S. Army Corps of Engineers,
Nebraska Game and Parks Commission, Nebraska Department of Environ-
mental Control, U.S. Environmental Protection Agency, and U.S. Fish
and Wildlife Service. Such materials could include landowner guides
to wetland vegetation, information on technical assistance programs,
and guidance on permit application.
- Development of additional tools to make the public aware of the
U.S. Army Corps of Engineers administered Section 404 Program and
how it affects landowner activities. This could be accomplished by
incorporating Section 404 regulatory information into public infor-
mation/education efforts and by encouraging the U.S. Army Corps of
Engineers and U.S. Environmental Protection Agency to target Rain-
water Basin counties for public information activities.
Information Needs
- Development and implementation of a Rainwater Basin wetland rela-
tional database to centralize permit data and individual wetland
data necessary to support regulatory determinations, justify the use
of "special cases" or Section 404(c), and prioritize acquisition
sites. !
- Development and implementation of a Geographic Information System
(GIS) to provide objective data necessary to prioritize and target
acquisition efforts at a macro scale and analyze permit actions.
Development and implementation of a basic hydrology model to predict
the probability of adequate water inputs necessary to restore
wetland character and values and as a tool for impact analysis.
- Initiation of a system for archiving historical aerial photography
and development of procedures for monitoring wetland trends for
future regulatory/resource management needs.
43
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LITERATURE CITED
Adamus, P. R. and L. T. Stockwell. 1983. A method for wetland func-
tional assessment: Volume I, critical review and evaluation
concepts, 176 pp., and Volume II, FHWA Assessment Method. 134 pp.
Benning, D.S. 1987. Coordinated mid-continent white-fronted goose
survey. U.S. Fish. Wild!. Serv. annual report. 7 pp.
The Conservation Foundation. 1988. Protecting America's wetlands:
an action agenda. The final report of the National Wetlands Policy
Forum. Washington, D.C. 69 pp.
Cowardin, L. M., V. Carter, F. C. Golet, andE. T. Laroe. 1979. Clas-
sification of wetlands and deepwater habitats of the United
States. FWS/OBS-79/31. Fish and Wildlife Service, Washington,
D.C. 103 pp.
Federal Interagency Committee for Wetland Delineation. 1989.
Federal Manual for Identifying and Delineating Jurisdictional
Wetlands. U.S. Army Corps of Engineers, U.S. Environmental
Protection Agency, U.S. Fish and Wildlife Service, and USDA Soil
Conservation Service, Washington, D.C. Cooperative technical
publication. 76 pp. plus appendices.
Federal Register. 1977 (19 July). Title 33: Navigation and
navigable waters; Regulatory program of the Corps of Engi-
neers. Vol. 42 (138), pp. 37122-37164, U.S. Government Print-
ing Office, Washington, D.C.
Federal Register. 1980 (24 December). Title 40; Part 230: Guidelines
for specification of disposal sites for dredged or fill mate-
rial. Vol. 45 (249), pp. 85336-85357, U.S. Government Printing
Office, Washington, D.C.
Federal Register. 1982 (22 July). Title 33; Parts 320-330: Interim
final rule for regulatory programs of the Corps of Engineers.
Vol. 47 (141), pp. 31794-31834, U.S. Government Printing Office,
Washington, D.C.
Federal Register. 1984 (5 October). Title 33; Parts 320, 323, 325,
and 330. Final Regulation for controlling certain activities in
waters of the United States. Vol. 49 (195), pp. 39478-39485, U.S.
Government Printing Office, Washington, D.C.
44
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Folkers, J. C. 1988. Rainwater Basin project boundaries for geo-
graphic information system development. Internal memo, U.S. Army
Corps of Engineers, Omaha District. 2 pp.
Gersib, Richard A., B. Elder, K.F. Dinan, and T.H. Hupf. 1989a.
Waterfowl values by wetland type within Rainwater Basin wetlands
with special emphasis on activity time budget and census data.
Nebraska Game and Parks Commission and U.S. Fish and Wildlife
Service. 105 pp.
Gersib, Richard A., R. Raines, W. Rosier, M. Gilbert. 1989b. A
functional assessment of selected wetlands within the Rainwater
Basin area of Nebraska. .Nebraska Game and Parks Commission,
Lincoln, Nebraska. 20 pp.
Gersib, Richard A., J. Comely., A. Trout, J. Hyland and J. Gabig.
1990. Concept plan for waterfowl habitat protection: Rainwater
Basin area of Nebraska. Nebraska Game and Parks Commission,
Lincoln, Nebraska. 71 pp. ;
Gilbert, Michael C. 1989. Ordination and mapping of wetland commu-
nities in Nebraska's Rainwater Basin region. CEMRO Environmen-
tal Report 89-1, Omaha District, U.S. Army Corps of Engineers,
Omaha, Nebraska.' 105 pp.
Jensen, S.F., M.P.A. 1987. Jordan River wetland advance identifica-
tion study—wetland functional assessment interpretive report,
final draft. Prepared for the U.S. Environmental Protection
Agency, Region VIII, Denver, Colorado. 56 pp.
Martin, A. C., N. Hotchkiss, F. M. Uhler, and W. S. Bourn. 1953.
Classification of wetlands of the United States. Spec. Sci.
Rpt. Wild!. 20. U.S. Fish and Wildlife Service, Washington,
D.C. 14 pp.
Nebraska Game
plan K-71.
and Parks Commission. 1972.
Lincoln, Nebraska. 78 pp.
Survey of habitat work
Nebraska Game and Parks Commission. 1984. Survey of habitat work
plan K-83. Lincoln, Nebraska. 13 pp.
Odum, W.E., J. Harvey, L. Rozas, and R. Chambers. 1986. The func-
tional assessment of selected wetlands of Chincoteague Island,
Virginia. U.S. Fish and Wildlife Service, NWRC Open File Rep. 86-
7. 127 pp. H
Office of Technology Assessment, U.S. Congress
Their use and regulation. Washington, D.C.
1984. Wetlands:
Schildman, G. and J. Hurt. 1984. Wildlife disease and mortality sum-
mary (1950-1983). Nebraska Game and Parks Commission. Lincoln,
Nebraska. 77 pp.
45
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1
Smith, Brian J. and K.F. Higgins. 1990. Avian cholera and temporal
changes in wetland numbers and densities in Nebraska's Rainwater
Basin area. Wetlands 10:1-5.
Swanson, L.D. 1986. The profitability of wetland drainage in the
Rainwater Basin of Nebraska. Prepared for the U.S. Environmental
Protection Agency, Region VII, Kansas City, Kansas. 94 pp.
Tiner, R.W. Jr. 1984. Wetlands of the United States: current status
and recent trends. U.S. Department of the Interior, Fish and
Wildlife Service. U.S. Government Printing Office, Washington,
D.C. 55 pp.
U.S. Department of Agriculture. 1987. Hydric soils of the United
States. Soil Conservation Service, Washington, D.C.
U.S. Department of the Interior. 1954. Wetlands inventory of Nebras-
ka (reissued May, 1955). U.S. Fish and Wildlife Service, Office
of River Basin Studies, Billings, Montana.
U.S. Environmental Protection Agency. 1990. Rainwater Basin wetland
map atlas. Region VII, Kansas City, Kansas.
U.S. Fish and Wildlife Service and Nebraska Game and Parks Commis-
sion. 1986. Rainwater Basin of Nebraska migratory bird habitat
acquisition plan. 30 pp.
46
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