ST9905DR-SY050214 MITIGATION PLAN
FOR THE PROPOSED MODIFICATION
OF TRIBUTARY G-1 NORTH OF WEST
BETHEL ROAD IN COPPELL, DALLAS
COUNTY, TEXAS
USACE Project No.: 200400181
Applicant: City of Coppell, Texas
Prepared by Loretta Mokry
ALAN PLUMMER ASSOCIATES, INC.
February 14, 2005
Mitigation Plan for the Tributary G-l, Coppell, TX
US/iCE Project No.: 200400181
TABLE OF CONTENTS
Page
1
INTRODUCTION
MITIGATION PLAN
la. Avoidance and Minimization 5
lb. Alternatives Analysis 6
Alternative 1 - No Action Alternative 6
Alternative 2 - Upgraded Box Culverts and Concrete Lined Open Channel 6
Alternative 3 - Concrete Lined Open Channel 7
Alternative 4 - Precast Stone Lined Open Channel 8
Alternative 5 - Preferred Alternative - Earthen Channel with Gabion 9
Reinforced Slopes
2. Impacts of the Proposed Project 11
3. Goals and Objectives of the Mitigation Plan 12
4. Description of the Mitigation Area 12
5. Preliminary Jurisdictional Determination 14
6. Compensatory Mitigation Activities 14
7. Liens and Encumbrances 15
8. Protective Actions 15
9. Hydrology 16
9a. Furore Hydrology 16
9b. Flow 17
10. Substrate 19
11. Planting Plan 21
12. Planting Success 23
13. Performance Standards 23
14. Mitigation Plan Benefits vs. Impacts 24
15. T&E Species 26
16. Other Impacts 26
17. Long Term Operation and Management Plan 27
18. Monitoring 28
19. Monitoring Reports 29
20. Mitigation Specialist Info 30
21. Mitigation Plan Schedule 30
22. Deed Restriction 31
APPENDIX A CORRESPONDENCE REGARDING REQUEST FOR
VARIANCE FROM CITY ORDINANCE
APPENDIX B - FIGURES AND EXHIBITS
APPENDIX C - PRELIMINARY JURISDICTIONAL DETERMINATION REPORT
PREPARED BY INTEGRATED ENVIRONMENTAL SOLUTIONS, INC.
DATED 26 NOVEMBER 2003
APPENDIX D - MAPPED SOIL SERIES IN PROJECT AREA
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USACE Project No.: 200400181
LIST OF TABLES
TABLE 1 - MODELED CHANNEL FLOWS AND VELOCITIES 18
TABLE 2 - SOIL DESCRIPTIONS FOR PROJECT AREA 19
TABLE 3 - MITIGATION PLANTING ZONES ALONG MODIFIED
SECTION OF TRIBUTARY G-1 21
TABLE 4 - COMPARISON OF ECOLOGICAL BENEFITS OF MITIGATION
PLAN VS. EXISTING AQUATIC RESOURCES ON PROJECT S1TE 24
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Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
Mitigation Plan for Modifications to Tributary G-1 North of West Bethel Road
within the City of Coppeil, Texas
USACE Project No.: 200400181
INTRODUCTION/BASELINE INFORMATION
Upland drainage channels and box culverts of a storm sewer system convey storm runoff from
the drainage basin for Tributary G-I which parallels the western portion of Bethel Road and
includes approximately 242 acres of Dallas-Fort Worth airport property which discharges into
Bethel Road at Royal Lane. An earthen uplands drainage channel constructed by the City of
Coppell in 1981 within a 60' wide drainage easement conveys drainage from an urban watershed
consisting of Heavy Industrial and Light Industrial to the jurisdictional channel of Tributary G-1
north of Bethel Road. The stream channel continues northward from Bethel Road for about 300
linear feet bordering a older residential area surrounded by newer industrial developments and
some commercial then tums eastward again and continues eastward, crossing under Coppell
Road South. This stream then continues eastward through Huntcrwood Park, a linear park along
the tributary, which is surrounded by established residential developments. The increase in
impervious area resulting from past urban development and collection and discharge of drainage
from culverts has produced a flashy flow resulting from rapid runoff from rooftops and parking
lots. Thc existing drainage channel upstream of Bethel Road, constructed by the City in 1981,
still reflects the 40-foot wide earthen channel that was constructed, which currently lies within a
narrow riparian corridor dominated by black willow (Salix nigra), eastern cottonwood (Populus
deltoides), green ash (Fraxinus pennsylvanica), and giant ragweed (Ambrosia trifida).
Downstream of Bethel Road, two residences bordering the tributary along the west bank are
endangered by severe erosion. Currently, a wooden footbridge crosses the tributary at a third
residence (the City does not plan to replace this footbridge) then the channel turns eastward
toward Coppell Road South. The narrow riparian corridor in this reach is dominated by Eastern
red cedar (Juniperus virginiana), sugar hackberry (Celtis laevigata) with some green ash and an
understory of Chinese ligustmm (Ligustrum sinense) and Japanese honeysuckle (Lonicera
japonica).
The drainage basin for Tributary G-1 above Coppell Road South has been the subject of
numerous studies since the early 1990s. The existing industrial uses are comprised of the Un/ted
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USACE Project No.: 200400181
year frequency storm. Designing for the 100-year fully developed storm is the criteria which has
been utilized, with few exceptions, in the City of Coppell since approximately 1990. However,
the engineering staff at the City of Coppell recognized the potential effect that the design of a
drainage system to accommodate the 100-year ultimate developed nmoff along Bethel Road
would have for downstream portions of tributary G1 and Grapevine Creek. Erosion problems
have already been noted along a portion of the tributary through the residential areas of Big
Cedar and Country Estates and evidence of erosion was noted in Hunterwood Park. The goal of
the drainage design was to detain the increased runoff difference between the undeveloped
airport land as it exists today and the future developed airport land. Meetings and discussions
between the City of Coppell staff and the Dallas-Fort Worth Airport representatives were held
for more than three years regarding the proposed plan for the provision of detention on the
airport property. The City of Coppell was informed in October 2002 that representatives of
Dallas-Fort Worth Airport would not commit to any detention now or in the future. As a result,
the City of Coppell requested that TranSystems evaluate the proposed design for the Bethel Road
drainage system as if no detention was provided by Dallas-Fort Worth Airport when they
developed to determine the capacity of the proposed drainage system as well as with the existing
level of development. Evaluation of the proposed system indicated that the system would
convey approximately 25-year storm flow with ultimate development without detention on the
airport property. City Staff recommended to City Council that a variance to Chapter 13 of the
Code of Ordinances be granted for the proposed project. The variance was approved by the City
Council in December 2002. Copies of correspondence detailing the meetings and conversation
with representatives of Dallas-Fort Worth Airport, the supplemental evaluation of the capacity of
the proposed drainage design, and the request for variance from the City Council is included in
Appendix A. Figures B-1 through B-17 including project location map, vicinity map from the
USGS topographic quadrangle (Grapevine), 2001 aerial photograph of project site, and exhibits
of the proposed design for the modified channel (Plan, profile, and cross-sections) are included in
Appendix B.
The following summarizes the objectives and design constraints for the proposed project.
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Objectives
· Provide protection from flooding and increased traffic safety on Bethel Road
· Provide protection from ongoing erosion and subsequent damage to private residences on
adjacent private property
· Provide conveyance of storm runoff and flood flows from an existing urban watershed
undergoing continuing development while minimizing potential for degradation of
downstream reaches of tributary and Grapevine Creek.
· Provide protection of existing infrastructure within the urban watershed including
roadways, sanitary sewers, water mains, and other utility lines.
· Provide protection of downstream reaches of tributary and Grapevine Creek from
increased erosion potential resulting from high velocity flows from impervious surfaces
within developing watershed.
· Provide water quality improvement of storm flows conveyed through the modified
tributary channel to minimize degradation of habitat quality in downstream reaches.
· Preserve existing riparian trees where possible and increase diversity of vegetative
species with mitigation planting to develop a high-quality riparian area contiguous with
the preserved high-quality riparian area downstream of the project area so that overall
habitat quality is enhanced as well as developing/preserving an aesthetically pleasing
linear green belt for the project area.
Constraints
· No tolerance for movement of channel due to the restricted area (60' wide drainage
easement) in which conveyance of flood flows must be achieved.
· Project design must protect existing infrastructure including a sanitary sewer main along
Bethel Road that cannot be lowered due to the flatness of existing grade within the sewer
main.
· More than one-third of the drainage basin lies outside the City of Coppell's jurisdiction
so City requirements for on-site detention cannot be enforced throughout the drainage
basin.
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Mitigation Plan for the Tributary G-l, Coppell, TX
US~ICE Project No.: 200400181
MITIGATION PLAN
la. Avoidance and Minimization
The proposed modifications to Tributary G-1 north of Bethel Road are needed to accommodate
drainage from developed and developing urban areas upstream of the Bethel Road crossing.
Several detention facilities have been constructed for recent developmems within the drainage
basin, as required by city ordinance, to restrict flows from developed land to pre-development
runoff volumes. However, a significant portion of the drainage area is owned by the Dallas-Fort
Worth Airport and lies outside the City of Coppell's jurisdiction and attempts to get commitment
from Dallas-Fort Worth for installation of detention facilities in conjunction with development of
this area have not been successful. Requesting and being granted a variance to the City's
ordinance requiring drainage capacity to accommodate the 100-year ultimate developed rtmoff
along Bethel Road achieved minimization of impacts that would have resulted from further
increasing the drainage capacity of Tributary G-1 upstream of Bethel Road. The reduction of
design criteria for drainage capacity and requirement for detention within the upstream drainage
area (where possible), results in minimization of impacts to downstream reaches of Tributary G-
l and Grapevine Creek. The reduction in design criteria also reduces the overall width of impact
for the modified channel so that high quality hard mast trees (pecans) within the riparian corridor
may be preserved.
The employment of open channel design for the modified channel reach with bioengineering
techniques enables some replacement of existing functions within this ephemeral drainageway
(including the upland drainage channel and jurisdictional tributary channel) on-site. The
proposed planting of native grasses, legumes, and wildflowers within the modified channel (as
detailed in Section 11) will provide substantial water quality improvement of the storm runoff
from the developed urban drainage basin. The preservation of existing mature trees within the
project area where practicable along with the mature trees adjacent to the project area and
proposed planting of native trees and shrubs and native herbaceous species along the banks of
the stream channel will provide shading of the stream flows to minimize impacts to water
temperature and well as an enhanced contiguous riparian corridor habitat with greater
biodiversity to support local wildlife. The meandering base flow channel (which as designed
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US/iCE Project No.: 200400181
will acconunodate approximately 4% of the bank-full channel volume) will provide additional
detention time and water quality improvement for the typical irrigation runoff flows from the
urban area. The proposed modified channel will also provide protection from flooding and
erosion of adjacent private properties and increased traffic safety on Bethel Road by facilitating
drainage from the roadway.
lb. Alternatives Analysis
The following descriptions of altematives evaluated contain information regarding project
components including improvement or changes to drainage features and structures within the
drainage basin upstream of the jurisdictional waters of the U.S. This information is included to
provide a more complete tmderstanding of the overall scope of the project.
Alternative 1 - No Action Alternative
To accommodate drainage resulting from urban development within the drainage basin of the
headwaters of Tributary G-l, several measures have been employed. These include the
requirement for development of onsite storm water detention facilities for developments that
have occurred since 1991. However, onsite, detention facilities are not sufficient to manage or
convey drainage from this urbanized drainage basin without further degradation of the existing
tributary channel and potential flooding of roadways and private property. Currently, erosion
along the channel downstream of Bethel Road imperils the structural integrity of two private
residences. The City of Coppell has a responsibility to manage storm water appropriately to
protect the safety of its citizens and investments in public and private property. Therefore, the no
action alternative is not considered a viable alternative by the City of Coppell.
Alternative 2 - Upgraded Box Culverts and Concrete Lined Open Channel (from Final
Drainage Report for Regional Detention Analysis/Bethel Road Improvements prepared by
TranSystems Corporation~ December 20~ 2002)
This alternative provides for improvements to accommodate proposed development within
drainage basin G-1 utilizing the existing detention facilities (north of Bethel Road) and detention
storage in the upper reaches of thc drainage basin (Dallas-Fort Worth property) including an
upgrade to the 10' x 5' box culvert along the Minyard property.
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US/iCE Project No.: 200400181
· Construction of two off-channel detention ponds (16.9 ac-ft and 46.3 ac-ft) within the
Dallas-Fort Worth property at a cost of $1,073,000.
· Improved storm drainage system for the proposed Bethel Road widening at a cost of
$377,26O.
· Upgrading the currently undersized 10' x 5' box culvert between Freeport Parkway and
the USPS channel to add 3-2,040 linear feet of 10' x 5' box culverts along with
realigning approximately 140 linear feet of existing culvert at a cost of $2,480,679.
· Re-configuration of the existing earthen drainage channel between Freeport Parkway to
Bethel Road to a 32' wide bottom, 1:1 side slope, 6' deep concrete lined channel, at a
cost of $488,400.
· Upgrade the existing crossing of Bethel Road to accommodate upstream development by
placing 4-10' x 5' box culverts at a cost of $81,477.
· Upgrade and reconfigure approximately 350 linear feet of the existing jurisdictional
tributary channel downstream of Bethel Road (to approximately 275 linear feet upstream
of Coppell Road) to a 32' wide bottom, 1:1 side slope, 6' deep concrete lined channel, at
a cost of $352,930.
The total cost of Alternative 2 (in 2002 dollars) is estimated to be $4,853,746 plus 15%
contingency = $5,581,808. The projected cost were prepared as part of an engineering study and
do not include costs for off-site mitigation. The proposed design of replacement box culverts
followed by concrete-lined trapezoidal channel severely limits opportunity for on-site mitigation.
Alternative 3 - Concrete Lined Open Channel (from Final Draina~,e Reoort for ReRional
Detention Aha ,lysis/Bethel Road Improvements prepared by TranSystems Corporation~
December 20~ 2002)
This alternative provides for improvements to accommodate proposed development within
drainage basin G-1 utilizing the existing detention facilities (north of Bethel Road) and detention
storage in the upper reaches of the drainage basin (Dallas-Fort Worth property) including an
upgrade of the 10' x 5' box culvert along the Minyard property to a trapezoidal concrete lined
channel.
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USACE Project No.: 200400181
· Construction of two off-channel detention ponds (16.9 ac-ft and 46.3 ac-fi) within the
Dallas-Fort Worth property at a cost of $1,073,000 (identical to alternative 2).
· Improved storm drainage system for the proposed Bethel Road widening at a cost of
$377,260 (identical to alternative 2).
· Upgrading the currently undersized 10' x 5' box culvert between Freeport Parkway and
the USPS channel to a 32' wide bottom, 3"1 side slope, 6' deep concrete lined channel at
a cost of $1,333,306.
· Reconfiguration of the existing earthen drainage channel between Freeport Parkway to
Bethel Road to a 32' wide bottom, 1:1 side slope, 6' deep concrete lined channel at a cost
of $488,400.
· Upgrade the existing crossing of Bethel Road to accommodate upstream development by
placing 4-I0' x 5' box culverts at a cost of $81,477.
· Upgrade and reconfigure the existing channel from Bethel Road to approximately 275
linear feet upstream of Coppell Road to a 32' wide bottom, 1:1 side slope, 6' deep
concrete lined channel at a cost of $352,930.
The total cost of alternative 3 is estimated to be $3,706,373 plus 15% contingency ~ $4,262,329.
The projected cost were prepared as part of an engineering study and do not include costs for off-
site mitigation. The proposed design of a concrete-lined trapezoidal channel severely limits
opportunity for on-site mitigation.
Alternative 4 - Precast Stone Lined Open Channel (from Final Drainage Re~ort for
Regional Detention Analysis/Bethel Road Improvements prepared by TranSystems
Corporation~ December 20~ 2002)
This alternative provides for improvements to accommodate proposed development within
drainage basin G-1 utilizing the existing detention facilities (north of Bethel Road) and detention
storage in the upper reaches of the drainage basin (Dallas-Fort Worth property) including an
upgrade of the 10' x 5' box culvert along the Minyard property to a precast stone lined concrete
channel.
· Construction of two off-channel detention ponds (16.9 ac-fl and 46.3 ac-fi) within the
Dallas-Fort Worth property at a cost of $1,073,000 (identical to alternatives 2 and 3).
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Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
· Improved storm drainage system for the proposed Bethel Road widening at a cost of
$377,260 (identical to alternatives 2 and 3).
· Upgrading the currently undersized 10' x 5' box culvert between Freeport Parkway and
the USPS channel to a 40' wide by 7' deep precast stone lined channel at a cost of
$1,214,906.
· Reconfiguration of the existing channel between Freeport Parkway to Bethel Road to a
40' wide by 7' deep precast stone lined channel at a cost of $534,900.
· Upgrade the existing crossing of Bethel Road to accommodate upstream development by
placing 4-10' x 5' box culverts at a cost of $81,477.
· Upgrade and reconfigure the existing channel from Bethel Road to approximately 275
linear feet upstream of Coppell Road to a 40' wide by 7' deep pavestone lined channel at
a cost of $352,430.
The total cost of alternative 4 is estimated to be $3,633,973 plus 15% contingency = $4,179,069.
The projected cost were prepared as part of an engineering study and do not include costs for off-
site mitigation. The proposed design of a stone-lined trapezoidal channel limits opportunity for
on-site mitigation.
Alternative 5 - Preferred Alternative - Earthen Channel with Gabion Reinforced Slopes
This altemative provides for improvements to accommodate proposed development within
drainage basin G-1 utilizing the existing detention facilities (north of Bethel Road) and detention
storage in the upper reaches of the drainage basin (Dallas-Fort Worth property) including an
upgrade of the 10' x 5' box culvert along the Minyard property to a precast stone lined concrete
channel and modification of the approximately 830 linear feet of existing upland earthen
drainage channel from Freeport Parkway through Bethel Road plus 350 linear feet of Tributary
G-1 channel downstream from Bethel Road to a 35'-wide bottom width channel with
meandering 5'-wide and approximately 2'-deep base-flow channel (base flow channel
accommodates approximately 4% of the bank-full channel volume) and constructed gabion
protected slopes at a 1:1 side slope with an overall top width of 50 feet. Native herbaceous
vegetation (as described in Section 11) would be planted in the channel bottom along the base-
flow channel and native canopy trees, small trees and shrubs, and herbaceous vegetation would
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Mitigation Plan for the Tributary G-l, Coppell, TX
US~ICE Project No.: 200400181
be planted along the top of bank within a 5' wide strip between the top of each side of the stream
bank and the 60'-wide drainage fight-of-way boundaries.
· Construction of two off-channel detention ponds (16.9 ac-it and 46.3 ac-fi) within the
Dallas-Fort Worth property at a cost of $1,073,000 (identical to alternatives 2, 3 and 4).
· Improved storm drainage system for the proposed Bethel Road widening at a cost of
$377,260 (identical to alternatives 2, 3 and 4).
· Upgrading the currently undersized 10' x 5' box culvert between Freeport Parkway and
the USPS channel to add 3-2,040 linear feet of 10' x 5' box culverts along with
realigning approximately 140 linear feet of existing culvert at a cost of $2,480,679.
· Reconfigure the existing earthen drainage channel between Freeport Parkway to Bethel
Road to a 6' deep, 35'-wide bottom width channel with meandering 5'-wide base-flow
channel (conveying approximately 4% of bank full volume) and constructed 1:1 stepped
side gabion protected slopes with an overall top width of 50 feet at a cost of $466,420.
· Upgrade the existing crossing of Bethel Road to accommodate upstream development by
placing 4-10' x 5' box culverts (approximately 45 linear feet) at a cost of $81,477.
· Reconfigure approximately 350 linear feet of the existing tributary channel downstream
of Bethel Road (to approximately 275 linear feet upstream of Coppell Road South) to a 6'
deep, 35'-wide bottom width channel with meandering 5'-wide and 1-2 feet deep base-
flow channel and constructed 1:1 stepped side gabion protected slopes with an overall top
width of 50 feet at a cost of $299,842.
· Plant native herbaceous species along the channel bottom and native canopy trees, small
trees and shrubs, and herbaceous species along the banks of the modified upland drainage
channel between Freeport Parkway and Bethel Road and tributary channel downstream of
Bethel Road at a cost of $16,000.
The total cost of alternative 5 is estimated to be $4,794,678 plus 15% contingency = $5,513,880.
The proposed design of gabion-reinforced side slopes with earthen bottom provides opportunity
for on-site mitigation. Plan, profile, and typical cross-section views of the preferred design
alternative are included as Figures 4 through 11 in Appendix B.
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Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
2. Impacts of the Proposed Project
The impacts of the proposed project to jurisdictional waters of the U.S. are limited to the
tributary channel segment north of Bethel Road to be modified which totals approximately 350
linear feet. Since both banks of the stream channel will be stabilized, the project entails
approximately 700 linear feet of bank stabilization. Limiting design criteria for the
modifications to conveyance of the runoff from the 25-year frequency storm event maintains pre-
development runoff volumes and minimizes the potential for increases in flow velocity.
Therefore, the downstream reaches of Tributary G-I and Grapevine Creek will not be subjected
to potential increases in erosion rates as a result of the proposed project.
Within the earthen drainage and tributary channel segments to be modified, existing vegetation
as well as accumulated debris and sediment within the modified channel footprint will be
removed during excavation to enlarge and reshape the channel. However, mature trees that are
located within the riparian corridor outside the limits of required excavation for the proposed
projectwill be protected and preserved (Note: Some trees are on private property outside of the
60-foot drainage easement.). In addition to the preserved mature trees, a mixture of native trees,
shrubs, and herbaceous species (as detailed in Section 11) will be planted along and within the
modified channel reach to increase biodiversity, enhance habitat for wildlife species, and provide
an aesthetically pleasing greenbelt for local residents and workers. The proposed plantings will
also serve to stabilize the soils of the modified channel to minimize sediment loadings to
downstream reaches of the tributary channel. Appropriate use of construction best management
practices and isolation of construction areas from storm flows will be used to control temporary
sediment loadings from disturbed areas during construction. The design of the modified channel
will serve to dissipate storm rtmoff velocities to reduce erosive impacts downstream providing
minimization of long-term impacts to the downstremn receiving waters.
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Mitigation Plan for the Tributary G-l, Coppell, TX
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3. Goals and Objectives of the Mitigation Plan
The goal of the mitigation plan is to replace existing functions (as presented in Sectionl4, Table
3) lost as a result of impacts of the proposed modification and enhance the functions of the
modified drainage and tributary channels so that aquatic resources downstream are protected
from degradation.
A list of qualitatively and/or quantitatively measurable outcomes of the proposed mitigation plan
that can be used to demonstrate that its goal is being achieved includes, but is not limited to the
following:
1. Maintain storm runoff capacity and provide erosion protection to protect public and
private properties along thc tributary channel.
2. Foster continued stream conveyance (both low flows and high flows) within a channel
with a vegetated earthen bottom and contiguous riparian corridor.
3. Increase vegetative species diversity with an increase in species that provide high-quality
wildlife habitat, aesthetics, erosion control, and water quality improvement.
4. Provide a riparian buffer to the extent practicable to filter runoff from the adjacent urban
areas.
5. Maintain detention time and reduce runoff velocities to prevent increased potential for
erosion downstream as a result of the proposed project.
4. Description of the Mitigation Area
The proposed mitigation area is within the 60' drainage right-of-way being purchased by the City
of Coppell through which Tributary G-1 flows from Bethel Road West downstream toward
Coppell Road South. The drainage basin within the proposed project area comprises
approximately 700 acres with several land uses including heavy industrial, light industrial, and
residential. The City of Coppell constructed the earthen drainage ditch upstream of Bethel Road
to Freeport Parkway in 1981 with a 20-foot bottom width and 40-foot overall width earthen
channel with a flow line of +0.30% within a 60-foot drainage easement acquired for the
construction. The 40-foot wide channel with 20-foot wide bottom and 3:1 side slopes of the
constructed channel are still evident throughout the length of the channel based on recent
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topographic survey conducted by TranSystems in 2004 in conjunction with design for the
proposed project. Esters Road was reconstructed with a storm drain system that discharged into
the channel at the same time. The urbanization of the drainage basin and increased storm runoff
flow volumes and velocities prior to the establishment of city ordinance in 1991 requiring
detention facilities to restrict flows from developed land to pre-development runoff volumes
resulted in severe erosion along the reach of the tributary channel downstream of Bethel Road.
The continuing degradation of the eroded stream banks jeopardizes adjacent residential
structures. The natural stream channel is narrower than the upstream drainage channel with
almost vertical side slopes. The existing narrow riparian corridor is dominated by cottonwood,
black willow, hackberry (Celtis laevigata), box elder (Acer negundo), green ash (Fraxinus
pennsylvanica), and cedar elm (Ulmus crassifolia) in the reach upstream of Bethel Road West
and by eastern red cedar, pecan, bitter pecan (Carya aquatica), and hackberry downstream of
Bethel Road West. Dominant understory species upstream of Bethel Road West included annual
ragweed, Johnsongrass (Sorghum halepense), and poison ivy (Toxicodendron radicans), while
dominant understory species between Bethel Road West and Coppell Road South included
Chinese ligustmm, waxleaf ligustrum (Ligustrum quihoui), Japanese honeysuckle, poison ivy,
and mustang grape (Vitis mustangensis).
The stream is characterized as ephemeral due to lack of groundwater inflows. Irrigation runoff
and discharge from detention ponds within the urban drainage basin may produce a more
sustained flow within the channel on occasion but observations of the stream channel six days
after a 2.28" rainfall event found the majority of the channel dry. The location of the drainage
and tributary channel within a highly urbanized landscape as well as contaminants within the
urban runoff and the eroded channel produced by the flashy storm runoff flows have resulted in
minimal wildlife habitat within the drainageway corridor. The project location map and USGS
topographic quadrangle of the project area are included as Figures 1 and 2 of 11 in Appendix B.
The 2003 aerial photograph included as Figure 3 of 17 in Appendix B indicates the project area
and surrounding landscape as well as the two residences most impacted by channel erosion.
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Mitigation Plan for the Tributary G-l, Coppell, TX
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5. Preliminary Jurisdictional Determination
Integrated Environmental Solutions, Inc. conducted a preliminary determination of jurisdictional
waters of the United States (U.S.) for the project site. A report documenting the survey, dated 26
November 2003, is included in Appendix C. The conclusion of the survey was that the only
potential jurisdictional water of the U.S. was the single unnamed ephemeral channel (tributary
G-l) to Grapevine Creek) which was approximately 1,723 linear feet (to Coppell Road South)
and averaged between 2 and 10 feet wide at the ordinary high water mark (OHWM) (0.222 acre
total). Subsequent review of records and historical documentation presented in correspondence
from the City to the USACE, dated October 7, 2004, regarding the construction and use of the
channel south of Bethel Road to Freeport Parkway has led the USACE to determine that the
portion of the channel upstream of Bethel Road is non-jurisdictional uplands drainage.
Therefore, jurisdictional waters of the U.S. within the project site is limited to the tributary
channel downstream of Bethel Road to Coppell Road South consisting of approximately 350
linear feet.
6. Compensatory Mitigation Activities
Several enhancements are proposed along Tributary G-1 downstream of Bethel Road to provide
compensatory mitigation for unavoidable impacts as a result of the proposed project. The
modified channel design includes a meandering base flow channel approximately 5 feet wide and
1-2 feet deep within a 6' deep, 35'-wide bottom width channel constructed with 1:1 stepped side
gabion protected slopes with an overall top width of 50 feet. The base flow channel will convey
approximately 4% of the volume relative to bank full flow conditions. Installation of a rock
gabion mattress between the headwalls downstream of W. Bethel Road will provide both erosion
protection and a riffle zone downstream of the box culverted road crossing to enhance aeration of
storm flows. The enhancements to the channel include the establishment of native herbaceous
species to stabilize the bottom width of the overall modified channel and the meandering base-
flow channel within the channel bottom. The proposed mixture of native grasses, legumes, and
wildflower will also provide filtration of flows for water quality improvement, flow attenuation
and dissipation of erosive storm flow velocities, and some habitat functions for wildlife. In
addition to the herbaceous species to be planted within the channel bottom, a variety of native
Alan Plummer Associates, Inc. Page 14
Mitigation Plan for the Tributary G-l, Coppell, TX
US,4CE Project No.: 200400181
canopy trees, small trees and shrubs, and a mixture of herbaceous species will be planted along
the top of the stream banks which with the preserved mature trees in the project area will provide
a contiguous riparian corridor with increased diversity and quality of food sources for wildlife as
well as provide long-term stability of the stream channel. The established riparian corridor will
also provide an aesthetically pleasing vegetative screen of adjacent industrial areas. A more
detailed discussion of the mitigation vegetation to be planted along the modified segments of
Tributary G-1 can be found in Section 11.
The City proposes to construct channel modifications to approximately 830 LF of non-
jurisdictional upland drainage channel from Freeport Parkway to Bethel Road. The proposed
modifications are the same or similar to those proposed for the jurisdictional section of Tributary
G-I. Enhancement of the modified upland drainage channel with plantings of herbaceous native
species within the channel bottom and a variety of native canopy trees, small trees and shrubs,
with an understory of herbaceous species is included.
7. Liens and Encumbrances
The City of Coppell will purchase a drainage easement with appropriate deed restrictions for the
mitigation area for Tributary G-l, from north of Bethel Road to the end of the proposed
improvements. The uplands drainage channel, from Freeport Parkway to just south of Bethel
Road lies within an existing 60-wide drainage easement to the City of Coppell. The section of
channel south of Bethel Road not currently within a drainage easement is located on a parcel of
land owned by the City. There are no known liens or encumbrances existing that will affect the
proposed mitigation area.
8. Protective Actions
Multiple actions will be taken during construction to protect water quality within tributary G1
and downstream receiving waters including Grapevine Creek and associated buffer zones
adjacent to the project area. These actions include but are not limited to: confining construction
materials and debris to the construction site; stabilizing disturbed areas at the earliest possible
date with the use of permanent or temporary vegetation, blankets, or matting, mulch, or sod;
Alan Plummer Associates, Inc. Page 15
Mitigation Plan for the Tributary G-l, Coppell, TX
USA CE Project No.: 200400181
isolating the project area from downstream segments by using and maintaining sand bag berms,
silt fencing, triangular filter dikes, rock berms, or hay bale dikes below the downstream portion
of the project area; protecting vegetation from unnecessary damage; and performing all proposed
construction activities within the reaches of the stream channel during low flow conditions to
minimize sediment introduction into downstream reaches including Tributary G1 and Grapevine
Creek.
The excavation and construction of the proposed channel will be conducted in two phases. First
excavation of the east/south side of the proposed channel to the subgrade elevation will be
conducted and gabions, box culverts, and headwall installed while conveyance of storm flows is
maintained in the existing undisturbed stream channel to the west/north. The existing stream
channel will be protected from construction activities during this first phase with the use of
appropriate signage and construction fencing to identify protected areas within the construction
work zone. Since the upland drainage channel and Tributary G-1 are both characterized as
ephemeral, the construction activities for the proposed channel modifications will be conducted
during dry conditions (not during or immediately after storm events). After completion of
installation of gabion baskets and box culverts on the east/south side, the modified stream
channel will be planted with the permanent vegetation specified in the mitigation plan. Storm
flows will then be routed to the modified side of the proposed stream channel and phase two
construction will begin on the west/north side of the proposed channel. Excavation of the
west/north side of the proposed channel and construction activities for installation of the gabion
baskets, box culverts, and headwall will be isolated from storm flows in the east/south side of the
modified channel. Following completion of construction, the west/north side of the proposed
channel will also be planted with the permanent vegetation specified in the mitigation plan and
flows will be rcrouted to a meandering base flow channel in the bottom of the modified channel.
9. Hydrology
9a. Future Hydrology
The future hydrology of the modified channel segment within the project area and downstream
reaches of tributary G1 will consist of storm runoff from the approximately 700 acre drainage
Alan Plummer Associates, Inc. Page 16
Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
basin above Coppell Road South. The land uses within the drainage basin currently include
heavy industrial, light industrial, and residential with some undeveloped land areas in the upper
watershed, including approximately 242 acres of Dallas-Fort Worth airport property. Future
development of these areas may include industrial and/or commercial properties. Runoff from
the existing developed and undeveloped portions of the watershed will continue to be conveyed
through the modified channel in a manner similar to existing conditions prior to the modification.
Depending on whether or not construction of additional detention basins is conducted in
conjunction with future development within the Dallas-Fort Worth airport portion of the
watershed, storm runoff flows will either be maintained at existing conditions or increase as the
pement impervious surface area increases.
The elevation drop along the modified channel will remain similar to current conditions. The
center towline of the existing channel slopes from elevation of 501' msl just downstream of the
culverted crossing at Bethel Road to an elevation of 497' msl approximately 350 linear feet
downstream; the 2' elevation drop over the 350 linear feet representing a slope of 0.57%. The
center towline for the proposed modified channel will transition from an elevation of 502.45'
msl to 499' msl approximately 350 linear feet downstream, representing a slope of 0.99%.
9b. Flow
The modified channel for tributary Gl, as designed, will convey the runoff from the existing
drainage basin for resulting flows from up to the 100-year frequency storm. At ultimate build-
out, if Dallas-Fort Worth Airport property is not developed with additional detention facilities,
the designed channel modifications will have the capacity to convey flows resulting from up to
the 25-year frequency storm (Effective storm capacity). The modified channel is designed with
appropriate armoring to convey these storm nmoff flows so that the channel is protected from
erosion and erosive energies within the storm flows are dissipated to minimize adverse erosive
impacts to downstream natural reaches of the channel. Projected 100-year storm event volumes
(Q) and flow velocities within the modified channel at designated stations for the existing
drainage basin and for ultimate build-out conditions without additional detention facilities based
on the hydraulic modeling conducted during design are presented in Table 1.
Alan Plummer Associates, Inc. Page 17
Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
TABLE 1: MODELED CHANNEL FLOWS AND VELOCITIES
Station Development Condition Q Total (cfs) Channel Velocity
(fi/sec)
Freeport Parkway (downstream Existing (2-year 866 7.45
of culvert - approximate Discharges)
drainage area = 406 acres) Ultimate (2-year 1200 8.17
Discharges)
Existing ( 100-year 1580 8.67
Discharges)
Ultimate ( 100-year 2515 11.08
Discharges)
Effective (100-year 2300 9.96
Discharges)
Bethel Road (downsl~eam of Existing (2-year 866 2.84
culvert - approximate drainage Discharges)
area - 464 acres) Ultimate (2-year 1200 3.58
Discharges)
Existing ( 100-year 1924 10.09
Discharges)
Ultimate ( 100-year 2755 l 0.68
Discharges)
Effective (100-year 2300 10.64
Discharges)
Upstream of Coppell Road Existing (2-year 866 1.97
(approximate transition to Discharges)
natural channel - approximate Ultimate (2-year 1200 2.54
drainage area - 676 acres) Discharges)
Existing (100-year 1924 11.21
Discharges)
Ultimate (100-year 2755 10.55
Discharges)
Effective (100-year 2300 11.08
Discharges)
At Coppell Road (approximate Existing (2-year 866 1.44
drainage area 700 acres) Discharges)
Ultimate (2-year 1200 1.84
Discharges)
Existing ( 100-year 1924 4.86
Discharges)
Ultimate (100-year 2755 5.25
Discharges)
Effective ( 100-year 2300 5.23
Discharges)
No groundwater discharge was observed within the stream channel reach where modifications
are proposed.
Alan Plummer Associates, Inc. Page 18
Mitigation Plan for the Tributary G-l, Coppell, TX
USA CE Project No.: 200400181
10. Substrate
According to the information from the Soil Survey for Dallas County, Texas (United States
Department of Agriculture, Soil Conservation Service in cooperation with Texas Agricultural
Experiment Station), the mapped soil units within the project area consist of clay loam and fine
sandy loam. The soil types are listed in Table 1. A complete description of the mapped soil
types encountered within the proposed project area is included in Appendix D.
TABLE 2: SOIL DESCRIPTIONS FOR PROJECT AREA
Map Unit # Soil Series ] Soil Description
79 Wilson Wilson clay loam, 1 to 3 percent slopes
12 Axtell Axtell fine sandy loam, 2 to 5 percent slopes, eroded
Since the proposed project does not involve the use of any supplemental soil and all the
vegetation proposed in the planting plan is native to Dallas Cotmty and/or ecoregion 5 (Cross
Timbers and Prairies) and adapted to the existing soil conditions, it is expected that the existing
soil should support all the proposed vegetation listed in the planting plan. The topsoil from the
project area will be stockpiled and used as the backfill behind the constructed gabions as well as
over the tops of the gabions for establishment of the seeded vegetative species specified in
Section 11.
For an estimate of sediment balance in the earthen channel upstream, between Bethel Road and
Freeport Parkway, the boundary shear stress at mean annual flow was compared to the Shields
criterion, which estimates the critical shear stress necessary for initiation of transport for a bed
sediment of a specific size:
Mean annual flow for the project reach was estimated from data available from several USGS
gage records for small urban streams in the Fort Worth area. Based on this data and the drainage
area for Tributary G-1 above Coppell Road which is 676 acres or just over one square mile, the
mean annual flow for the project reach should be on the order of 1 cfs. The base flow channel
will have approximately 1.5 times the length of the full channel because of the sinuosity that will
Alan Plummer Associates, Inc. Page 19
Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
be created. The slope of the full channel downstream of Bethel Road will be 0.99% and the
slope of the base flow channel will be about 0.65%.
For a mean annual flow of about I cfs, boundary shear stress is on the order of 0.08 lb/fi2.
Theoretically, entrainment of bed material should be expected when boundary shear stress
exceeds critical shear stress (~>~ ¢), but due to packing and particle shape, a more practical
estimate of the threshold for channel bed move is when the ratio of boundary shear stress to
critical shear stress exceeds 2.0. The Shields diagram indicates that the streambed is likely be
stable in normal flows. Movement would occur for particles corresponding to zc < 0.04 lb/ft2,
particles less than about 0.3 mm diameter. Though fine sediments could potentially be entrained
in normal flows, the coarse sands and gravels should be stable.
Shields Diagram
Critical Shear Stress in
Source: North Carolina Stream Restoration Institute
Alan Plurnrner Associates, Inc. Page 20
Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
11. Planting Plan
Various species of native trees, shrubs, and herbaceous vegetation will be planted to establish a
riparian corridor of native vegetation along and within the modified section of Tributary G1
channel. Although the width of the riparian buffer is limited by the existing constraints of the
project area listed before, these plantings will increase the diversity and quality of food sources
within the riparian corridor area as well as provide slope and bank stabilization, water quality
improvement, habitat for wildlife, and an aesthetically pleasing channel to the extent practicable.
The plantings include 178 canopy trees and 340 understory trees and shrubs. A mixture of
herbaceous species including native grasses, legumes, and wildflowers will be planted beneath
the tree and shrub species along the top of the bank. A mixture of selected herbaceous species
will also be planted along the meandering base flow channel within the stream bottom. Tables 2
list the vegetative species to be planted in the identified planting zones.
TABLE 3: MITIGATION PLANTING ZONES ALONG MODIFIED SECTION OF
TRIBUTARY G1
Zone A1 -Stream Channel Bottom Outside of Base Flow Channel and Gabion Baskets--
Herbaceous Vegetation Only
Common Name Scientific Name Seeding Rate
(Pounds/Acre)
Prairie Wildrye Elymus Canadensis 4
Virginia Wildrye Elymus virginicus 3
Grasses Inland Seaoats Chasmanthium latifoHum 4
Lowland Switchgrass Panicum virgatum 4
Indiangrass Sorghastrum nutans 4
Legumes Illinois Bundleflower Desmanthus illinoensis 15
Clasping Coneflower Rudbeckia amplexicaulis 1
Cutleaf or Engelmann Daisy Engelmanniapinnatifida 2
Wildflowers
Obedient Plant Physostegia intermedia 1
Scarlet Sage Salvia coccinea 2
Alan Plummer Associates, Inc. Page 21
Mitigation Plan for the Tributary G-l, Coppeil, TX
USACE Project No.: 200400181
TABLE 3: MITIGATION PLANTING ZONES ALONG MODIFIED SECTION OF
TRIBUTARY G1 (CONT.)
Zone A2 - Top of Bank of Modified Channel - Herbaceous Vegetation with Canopy Trees,
Small Trees, and Shrubs*
Common Name Scientific Name Number
Black Walnut Juglans nigra 20
Slippery Elm Ulmus rubra (~. fulva) 25
Canopy Chinquapin Oak Quercus muhlenbergii 25
Trees Shumard Oak Quercus shumardii 25
Bur Oak Quercus macrocarpa 8
Pecan Carga illinioensis 15 **
*Trees shall be at least 5-gallon container xown size or comparable size harvested from local
area.
**Does not include preservation of several mature pecan trees within existing riparian corridor
(not necessarily within 60 foot easement/future right-of-way).
Common Nan~e Scientific Name Number
Deciduous Holly Ilex deciduas 15
Texas Redbud Cercis texensis 8
Eve's Necklace Sophora af~nis 8
Small Rough-leaf Dogwood Cornus drummondii 30
Trees and Rusty Blackhaw Viburnum rufidulum 10
Shrubs Forestiera pubescens var.
Smoothleaf Elbowbush 60
glabrifolia
Coralberry Symphoricorpos orbiculatus 105
*Shrubs shall be at least 1-3 gallon container grown size or comparable size harvested from the
local area.
Herbaceous Seed Mixture
Common Name Scientific Name Seeding Rate
(Pounds/Acre)
Prairie Wildrye Elymus canadensis 3
Virginia Wildrye Elymus virginicus 4
Inland Seaoats Chasmanthium latifolium 4
Grasses
Little Bluestem $chizachyrium scoparium 3
Indiangrass Sorghastrum nutans 2
Silver Bluestem Bothriochloa laguroides 1
Legumes Illinois Bundleflower Desmanthus illinoensis 15
Alan Plummer Associates, Inc. Page 22
Mitigation Plan for the Tributary G-l, Coppeil, TX
USA CE Project No.: 200400181
Plains Coreopsis Coreopsis tinctoria 1
Lanceleaf Coreopsis Coreopsis lanceolata 2.5
Wildflowers Gayfeather Liatris mucronata 2.5
Huisache Daisy Amblyolepis setigera 2
Lemon mint Monarda citriodora 1
12. Planting Success
The planted mitigation areas will exhibit an 80 percent ground cover of herbaceous species three
consecutive years after planting or the areas will be replanted until an 80 pement ground cover is
achieved for three consecutive years after the most recent remedial planting and none of the three
most dominant species may be non-native, noxious, or invasive species.
The tree and shrub species specified in Section 11 will have a minimum survival of 80 percent of
the total number planted for five consecutive years after planting. Eligible trees will be those
specified in Section 11 and be at least one-inch diameter at breast height or six feet tall. Eligible
shrubs will also be those specified in Section 11 and be at least two feet tall. If the survival is
less than 80 percent within the designated mitigation areas five years after planting, the City will
replant as necessary to achieve the minimum density for five consecutive years after the most
recent remedial planting. Volunteer growth that meets the species and size criteria will be
eligible for counting.
13. Performance Standards
The mitigation area will be maintained until such time as the USACE is satisfied that waters of
the U.S. meet the definition of a water of the U.S. under the Regulatory Program regulations as
of this permit's authorization date and that this water of the U.S. is functioning as intended and at
the ecological level described in the mitigation plan, and buffer and riparian zones and other
areas integral to the enhancement of the aquatic ecosystem are functioning as the intended type
of ecosystem component and at the level of ecological performance described in this mitigation
plan.
Alan Plummer Associates, Inc. Page 23
Mitigation Plan for the Tributary G-l, Coppell, TX
U$.4CE Project No.: 200400181
materials
· Isolated,
intermittent pools
as
breeding/nursery
areas for
amphibians
· Perennial habitat
for fish
· Production of
autochthonous
material
· Diversity of
ecosystem
insects, birds, and small mammals
within this urban environment.
The allochthonous material
supplied to the tributary channel is
an important food source for
invertebrates, primarily insects and
mollusks, and fish that may exist
in downstream reaches of
Tributary G- 1 and Grapevine
Creek. The limited existing
canopy cover provides some
shading of stream channel to
prevent excessive temperatures.
However, the ephemeral nature of
the tributary within the project
reach (including any small pools)
limits habitat functions to
transitory species.
channel bottom along a
meandering base-flow channel
as well as establishing a
buffering riparian corridor to the
extent practicable within the
drainage easement along the
banks of the modified tributary
channel. Canopy trees, small
trees and shrubs and herbaceous
species are included within the
planting plan for the upper banks
of the tributary to provide
diversity and enhanced habitat
structure and substrate for
animals within the surrounding
area. The planted species will
also provide allochthonous and
autochthonous material to
downstream reaches of Tributary
G-1 and Grapevine Creek.
Quality hard-mast producing
trees existing within the riparian
corridor of the proposed project
area will be preserved wherever
possible and incorporated into
the overall design and mitigation
plan.
15. T&E Species
The proposed project is not expected to affect any listed threatened or endangered species.
16. Other Impacts
Due to the location and nature of the proposed project area, the proposed project is not expected
to affect any cultural resources. Correspondence with the Texas Historic Commission regarding
the removal of the existing box culvert at the Bethel Road crossing is included in Appendix E.
There are no ecologically sensitive areas identified within the vicinity of the project area. Finally
as a result of the proposed mitigation, the proposed project is not expected to adversely impact
either the local or regional hydrology.
Alan Plummer Associates, Inc. Page 26
Mitigation Plan for the Tributary G~I, Coppell, TX
USACE Project No.: 200400181
17. Long Term Operation and Management Plan
It is intended by the City of Coppell that the modified channel function with minimal
maintenance to provide designed conveyance of storm flows. The planted riparian area along the
banks of the channel will be allowed to develop as a natural area with minimal disturbance.
Mowing of this area will be limited to no more than 4X per year during the first two years, if
needed, as the planted mitigation species are establishing. Once the mitigation species are well
established, mowing will be limited to no more than IX per year during the dormant season
(December-January) to control woody colonizing species within the modified channel.
Colonization of the modified channel project area by invasive non-native plant species (including
but not limited to Chinese tallow tree (Sapiurn sebiferum), honeysuckle, and wax-leaf ligustrum)
should be inhibited by the extensive proposed plantings of native woody and herbaceous plant
species and annual mowing of the project area. However, any problem areas where non-native
plant species become the dominant plant cover will be treated by appropriate control measures
including but not limited to hand-pulling, cutting, or with an appropriate herbicide registered for
use in aquatic areas.
Trash and debris will be removed from the drainage structures and modified channel by City
personnel as needed to maintain flows and functions of the stream channel. City personnel will
periodically inspect the drainage structures and trash and debris will be removed as needed in a
manner that minimizes disturbance to the vegetation within the channel and along the channel
banks. Any disturbed area will be stabilized with appropriate vegetation as specified in Section
11 as soon as possible. Additional erosion control measures will be employed until vegetative
cover is re-established. Damage to gabion structures resulting from vandalism, erosion, or
failure that is observed during the periodic inspections will be reported to the City of Coppell
Engineering Department. Repairs will be scheduled in a timely manner to ensure the long-term
stability of the modified channel. Remedial measures requiring disturbance of more than 1/10t~
acre will be submitted to the USACE for review prior to implementation.
On January 27, 2004, the City Council approved Ordinance No. 2004-1070 which amended
Chapter 9 of the City of Coppell's Code of Ordinances by adding Sections 9-22-1 through 9-22-
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Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
5. Section 9-22-1 established the Municipal Drainage Utility System. Section 9-22-3 authorized
the City to establish a schedule of drainage charges against all real property within the City.
Section 9-22-5 established the criteria by which all real property within the City of Coppell
would be assessed under the Municipal Drainage Utility System. That section also stated that the
drainage charges shall be adopted by resolution. On March 9, 2004, after three public notices
had been published, the City Council adopted a schedule of drainage fees as follows:
Recommended Fee
(1)
Residential Property
a. Single-Family
b. Multi-Family
$1/per unit
$7/per acre
w/minimum fee of $5 and maximum fee of $75
(2)
Commercial/Industrial
a.
b.
C.
(3)
Day Care Centers/Churches
a.
b.
C.
$8/per acre
$9/per impervious acre
w/minimum fee of $5 and maximum fee of $75
$7/per acre
$9/per impervious acre
w/minimum fee of $5 and maximum fee of $75
The fees collected monthly under the Municipal Drainage Utility System will be used to offset
the City's cost to operate and conduct the Coppell municipal drainage utility system. These
funds will be available to address any maintenance issues arising with the gabion structures
utilized to stabilize the banks and control erosion around road crossing culverts of upland
drainage channel and Tributary G-1.
18. Monitoring
The progress of the mitigation area towards achieving the performance goals stated in the
mitigation plan will be monitored by measuring the development of hydrology, vegetation, soils,
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Mitigation Plan for the Tributary G-l, Coppeli, TX
USACE Project No.: 200400181
and habitat for aquatic and terrestrial wildlife. Monitoring deemed appropriate for the proposed
project and mitigation includes measuring the development of vegetative cover within the
modified stream channel bottom and the riparian corridor along the banks, determining survival
success of the planted trees and shrubs within the riparian cover, and developing a photographic
record of the progress of the mitigation area. Monitoring techniques to be employed for the
proposed project and mitigation may also include conducting plant inventories and noting
problem species.
19. Monitoring Reports
The City of Coppell, acting through its agent Alan Plununer Associates, Inc. will report to the
USACE monitoring results, mitigation success, and general compliance with the terms and
conditions of the permit. The USACE will be notified of the schedule of activities for each
phase of the proposed project and mitigation plan at least 30 days prior to the start of soil-
disturbing activities. Additionally, the USACE will be notified regarding the date of the pre-
construction meeting held by the City for appropriate contractor(s) to explain the terms and
conditions of the permit, provisions of the mitigation plan, and the contractor's responsibility in
ensuring compliance with the permit. Within two weeks following the meeting, the USACE will
receive confirmation that the meeting was held.
In addition to the above-mentioned notifications, the City will submit annual written compliance
reports, due October I each year beginning October 1, 2005 (or first year following issuance of
permit). These reports will be submitted to the USACE even if no work is conducted during the
reporting period until the USACE verifies that the City has successfully completed all mitigation
plan components, the mitigation area has met thc performance standards, including planting
success requirements as previously outlined in Section 12 of this mitigation plan and all
authorized construction activities have either been completed or deleted from the project. Each
report will contain at least a description of construction or mitigation plan schedule changes, a
summary of activities that occurred during the reporting period, documentation that the City is in
compliance with all permit conditions, documentation of the progress and/or completion of all
authorized work including mitigation plan activities in meeting performance standards and
planting success, a description of the project's actual impacts to waters of the U.S.,
Alan Plummer Associates, Inc. Page 29
Mitigation Plan for the Tributary G-l, Coppell, TX
US~ICE Project No.: 200400181
documentation that disturbed areas are revegetating and not suffering erosion damage,
documentation that adjacent aquatic areas are adequately protected from construction activities,
and photographs, maps and drawings to support the written components of the mitigation plan.
In addition to these components, the first annual report will also contain a written description of
the pre-construction conditions of the project area, including the mitigation area.
20. Mitigation Specialist Info
A qualified biologist from Alan Plummer Associates, Inc. 7524 Mosier View Court, Suite 200,
Fort Worth, Texas 76118-7122, Phone 817-806-1700, shall be retained to oversee project
construction, mitigation plan implementation, and reporting provisions for a period of two years.
The City will enter into an agreement with Alan Plummer Associates, Inc. or another qualified
firm for any reporting provisions required beyond this period.
21. Mitigation Plan Schedule
The schedule for the proposed project including past actions pertaining to the proposed project
and actions pertaining to the issuance of General Obligation Bonds for the Bethel Road I project
follows. The City of Coppell is scheduled to issue $8,750,000 in 2004 General Obligation Bonds
for the construction and offsite drainage for the Bethel Road I project. This is part of a larger
bond issue. The tentative bond issuance schedule indicates the City of Coppell will consider an
ordinance authorizing the issuance of said bonds on April 27, 2004. The bond closing and
delivery of funds to the City is scheduled for May 27, 2004
Design and Drainage Study Initiated by City
City Council Approval of Requested Variance
Correspondence with Texas Historic Commission (THC) re:
historic structure (box culvert at Bethel Road crossing)
Response received from THC re: box culvert
Development of information for Preparation of
Official Statements for Bond Counsel
Preparation of Draft Official Statements
February 13, 2001
December 10, 2002
February 2, 2004
February 13, 2004
February 27, 2004
March 5,2004
_ Alan Plummer Associates, Inc. Page 30
Mitigation Plan for the Tributary G-l, Coppell, TX
USACE Project No.: 200400181
specified, livestock grazing, mowing, and similar activities will not be allowed in the mitigation
area. The City will survey the mitigation area, develop an appropriate deed restriction for the
surveyed area, submit the draft deed restriction to the USACE for review and approval, and then
record the USACE-approved deed restriction with the Dallas County Clerk. The City will
provide a copy of the recorded deed restriction to the USACE within four months after receipt of
the 404 permit. The restriction will not be modified or removed from the deed without written
approval of the USACE. The conveyance of any interest in the property shall be subject to this
deed restriction.
The 60' drainage easement for the approximately 830 LF of drainage channel upstream of Bethel
Road was acquired in 1981 and the majority of the easement was dedicated as part of the Coppell
Commerce Center platting. The existing Koll Development and any future development on the
Coppell Commerce Center should not adversely impact the proposed riparian corridor. The City
will advise the owners of the Koll Development of the proposed mitigation and request that the
area not be disturbed by any activities that might affect its intended function. The City owns the
former Carter Crowley and Coppell Conunerce Center parcels located immediately south of
Bethel Road. A portion of the existing drainage easement is located on the parcels. The City
will work with any future development as to the intent of the mitigation area and request that the
area not be adversely impacted. The Camille Juraszek parcel and the City owned parcel
immediately to the east are primarily in the flood plain. The City has an ordinance against
building in the flood plain and it is unlikely that a LOMR will be prepared and the parcels
developed because of their small size. The parcel owners should not have any objections to the
proposed riparian corridor since it will replace an existing narrow riparian corridor that was
allowed to grow around the drainage channel.
Alan Plummer Associates, Inc. Page 32
Mitigation Plan for Modification of Tributary G1
USACE Project No.: 200400181
APPENDIX A
CORRESPONDENCE REGARDING REQUEST FOR
VARIANCE FROM CITY ORDINANCE
Alan Plummer Associates, Inc.
D:\OFFICE\816\02Ol\Tributary Gl Mit Plan_new. doc
AGENDA REQUEST FORM
COPPELL
DEs _; Engineering/Public Works
DATE: December 10, 2002
ITEM #: IO/E
ITEM CAPTION:
Consider approval of a variance to the Coppell Code of Ordinances Chapter 13, Appendix C Design Criteria and
Standards, Section II -
Road. Storm Sewers and Drainage, paragraph B Engineering Design for the construction of Bethel
IIII
GOAL(S): ~
ON ABOVE DATE
EXECUTIVE SUMMARY:
APPROVED BY
CITY COUNCIL
Mo?ion to Approve
' ~ M- Tunnel, - Peters
Vote - 7-0
Approval of this item will allow the design of West Bethel Road, from the west city limits to Freeport Parkway, to
proceed so that we can get back on schedule to bid the project for construction in late 2003.
Staff recommends approval of the variance to Chapter 13 of the Code of Ordinances and-will be ava/lable to
answer any questions at the Council meeting.
FINANCIAL COMMENTS:
DIR. REVIEW:
Ag~nd~ Requ~t Form - R~elsed 09/02
Docannenl Name: #eng2-1AR
MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To'-
From:
Date:
RE:
Mayor and City Council
Kenneth M. Griffin, P.E., Dir. of Engineering/Public Works
December 10, 2002
Consider approval of a variance to Subdivision Ordinance No. 94-643 of the
Code of Ordinances of the City of Coppell Appendix C Design Criteria and
Standards, Section II Storm Sewers and Drainage, paragraph B Engineering
Design.
The referenced section of the Subdivision Ordinance states "The Engineering design shall
generally conform to the criteria set forth in the City of Coppell City-Wide Storm Water
Management Study and the City of Dallas Drainage Design Manual." The Drainage Design
Manual for the City of Dallas states "All drainage systems will be designed to accommodate the
flow fi.om the 100-year frequency storm...". Designing for the 100-year fully developed storm
is a criteria that has been utilized in the City of Coppell since approximately 1990. There are
some drainage systems within the City of Coppell which are not designed onthe 100-year storm.
Most notably, the drainage system along MacArthur Blvd. fi.om Deforest Road south to Sandy
Lake Road is designed on a 5-year frequency storm.
Attached to this agenda item is a memo from myself to Jim Witt and Clay Phillips that goes into
great detail about our attempts to design the drainage system in West Bethel Road on a 100-year
design frequency. However, in designing systems for a 100-year frequency it is important to note
where you are discharging the collected water. In the case of West Bethel Road, if you were to
build a system to efficiently convey the 100-year design storm it would discharge water into the
small creek on the east side of Loch Lane then convey the water through the unimproved portion
of Grapevine Creek north of the Coppell Senior Citizens Center. This creek in tm'n meanders
adjacent to Old Coppell Estates, Big Cedar, Country Estates, Grand Cove, Creekview Addition,
etc. As Council may be aware, there have been several complaints of erosion in Grapevine Creek
adjacent to those subdivisions. To collect all of the water and discharge it into Grapevine Creek
on a 100-year design is not the appropriate design for this drainage system. At best, that would
be an irresponsible design that could create additional drainage problems downstream.
There have been two drainage studies performed on this drainage basin, the first in 1999 and the
second in 2002. Both studies point to the need for detention on the DFW Airport property. The
airport property comprises 242-acres of the 464-acres of drainage basin that drains to the
tributary on the east side of Loch Lane. This is approximately 52% of the entire drainage basin.
As can be seen by the detailed memo, there have been numerous meetings and conversations
with representatives of DFW Airport; however, in the final analysis, I have been told that DFW
"CITY OF COPPELL ENGINEERING ~ EXCELLENCE BY DESIGN"
Airport at this time will not support detention on their property nor acknowledge the concept or
need for detention.
At this time, I have three options conceming the drainage associated with West Bethel Road:
1. Indefinitely Postpone the project;
2. Build an efficient system that collects the 100-year runoff and discharge it into the
unimproved section of Grapevine Creek. This means seven 10'x5' box culverts within
Bethel Road discharging into the small tributary on the north side of Bethel Road east of
Loch Lane; or
3. Design a system that will handle the 100-year storm water runoff before the airport property
develops.
It is my opinion that Option 3 is the correct decision in the design of the drainage system. Option
3 gives us a 100-year ultimate storm drain system until such time as DFW Airport develops the
242-acres of their property that drains through the City of Coppell.
If they develop irresponsibly and discharge all their water into our system, then our drainage
system will still have the future capacity to convey a 25-year storm. If they do the correct thing
when they develop and design detention to detain the increase in runoff on their property, then
our system will continue to have a 100-year capacity in the furore. There are no guarantees on
what the future holds on the development of the airport property or whether or not the airport will
do a responsible development on the property in terms of drainage.
To keep the Bethel Road project moving ahead, my recommendation is that the variance to the
Subdivision Ordinance be approved to allow the construction of a drainage system that conveys
the 100-year runoff as it exists prior to development of the 242-acres of the airport property.
Staffwill be available to answer questions at the Council meeting.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To:
From:
Date:
RE:
Jim Wilt, City Manager
Clay Phillips, Deputy City Manager
Kenneth M. Griff'm, P.E., Dir. of Engineering/Public Works
November 14, 2002
Bethel Road Project ST 99-05
Since 1998, the City of Coppell has been evaluating drainage associated with West Bethel Road. In
1998 the City of Coppell hosted a meeting between the then property owners &the two large tracts
of land on the north side of Bethel Road to discuss the development of their property in regard to
drainage in Bethel Road. Those tracts of land are now referred to as the "Champion" and "Duke-
Weeks" tracts. The drainage basin for this portion of Bethel Road also includes approximately 240
acres of airport property discharging into Bethel Road at Royal Lane. In addition to that, the bulk
postal facility and the Minyards tract also discharge into Bethel Road. In total, there was
approximately 676 acres of land that discharged into Bethel Road near Coppell Road.
Realizing that drainage was going to be the overriding design consideration for the construction of
Bethel Road, a drainage study was commissioned by the City of Coppell called the "Southwest
Coppell Storm Water Management Master Plan". It was a joint venture between the City of
Coppell, NCH and Coppell Industrial NV. The study was prepared by Halffand Associates. The
study pointed to the fact that detention would be required on the land north of Bethel Road and on
the airport property. The detention on the airport property was crucial because of the short distance
from Royal Lane to Freeport Parkway and the fact that there was no available land in that section
for detention.
In 2001, the City of Coppell entered into a design contract with TranSystems Corporation for the
design of Bethel Road from the west city limits to Freeport Parkway. The design contract was
structured so that there would be additional drainage studies to complement the previous drainage
study. TranSystems' drainage study also pointed to the fact that detention would be required. By
this time, the property north of Bethel Road had already been developed by "Champion" and
"Duke-Weeks" and in both cases the City of Coppell required detention that would not allow the
discharge of any additional water from the site than what would normally discharge in an
undeveloped condition. Also, the water from the "Champion" and "Duke-Weeks" property was
conveyed in an easterly direction and discharged into Grapevine Creek north of Loch Lane, not
directly into Bethel Road.
"CITY OF COPPELL ENGINEERING. EXCELLENCE BY DESIGN" Page ! of 4
.The challenge now is to design a draln~o.e system that will convey a lO0-year storm and at thc
.same time not create any downstream erosion problems in Grapevine Creek TranSysterns has
provided two drainage studies for the City of Coppell to accommodate the drainage along Bethel
Road. Both studies show that detention will be required on the airport property. The detention on
the airport property is needed to detain the increase in water runoff when the 242-acres of airport
property develops. The last design by TranSystems shows two detention ponds strategically located
on the airport property generally along the west side of Royal Lane.
The design of a drainage system to accommodate the developed runoff along Bethel Road is not an
overwhelming engineering feat. Simply put, to convey the drainage along Bethel Road, it is only a
matter of installing additional box culverts. Preliminary design estimates arc that there would need
to be seven 10'x5' box culverts along Bethel Road to accommodate the 100-year ultimate
developed runoff. However~ the real challenge in this design is to balance the conveyance of
water with the potential for downstream erosion in Grapevine Creek As you may be aware,
we have had erosion along a portion of Big Cedar' and Country Estates and there is evidence of
erosion in Hunterwood Park. To effectively collect all the ultimate developed stormwater in a
drainage system in Bethel Road i.e., the constraction of seven 10'x5' box culverts, and convey that
water to Coppell Road and discharge it into Grapevine Creek just north of the Senior Citizens
Center would not be the wisest approach to accommodate the drainage associated with Bethel
Road. That approach would very effectively and rapidly convey a large amount of water to an
earthen channel and in effect create the potential for additional downstream erosion problems.
The goal in this drainage design is to detain the increased runoff difference between the
undeveloped airport land as it exists today and the future developed airport land Detention
on thc airport property is a critical component of this design. To that end, I met with
representatives of DFW Airport in July 2002 and presented them a copy of the revised draft
drainage report prepared by TranSystems. That report detailed the necessity for detention on the
airport property. I left a copy of the report for their review and asked them to respond to me
concerning the likelihood of a detention basin on airport property. I was even wi/ling to accept a
letter from the airport stating that if at some point in the future they chose to develop then they
would construct detention at that time.
I have a legal opinion from Pete Smith that states that the City of Coppell cannot require the airport
to abide by our subdivision rules and regulations in regard to the development of their property.
Therefore, unless the airport decides to create detention, the City of Coppell cannot require
detention, even on the section of land that lies within the City of Coppell. However, representatives
of DFW Airport stated that they are bound by EPA and other environmental rules and regulations
the same as any municipality. They also have to obtain all permits and approvals prior to
development of their property.
It was my hope based on the meeting, that I would receive correspondence from DFW Airport
stating that they understood the drainage situation and they would be willing to constxuct detention
on their property at a future date if they decided to develop the 240-acres that drain into the City of
Coppell. After numerous telephone calls, I was told in October 2002 that there would be no letter
forthcoming obligating DFW Airport for any future action.
Page 2 of 4
- "CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"
The situation we find ourselves in today is:
· 1) The airport will not allow us to construct detention on their property;
· 2) The airport will not commit to construct detention in the future; and
· 3) It is my professional opinion that it would not be wise to construct an effleient system to
discharge all the future water into Grapevine Creek knowing that there are downstream erosion
problems that exist today.
I contacted our consultant, TranSystems, and asked them to evaluate the drainage system that was
proposed with Bethel Road to determine what level of capacity we would have in the future if no
detention was constructed on the airport property. In essence, what I was asking is: if we build a
system today in anticipation of detention on the airport property in the future and the airport chose
not to construct detention, but instead chose to discharge all of their water into our "undersized"
drainage system what level of capacity would we have in our drainage system? The reply to that
question is that we would have a drainage system capable of conveying about a 25-year fully
developed storm. If the system only conveys approximately a 25-year storm, then any larger event
that we have i.e., 50 or 100-year storm, creates the potential for street flooding along Bethel Road.
The City of Coppell Subdivision Ordinance requires that drainage systems be designed for a 100-
year fully developed storm event. Without a detention basin, the drainage system cannot be
designed for a 100-year storm without discharging a substantial amount of water into an
unimproved section of Grapevine Creek. At this point, I find myself at a standstill on moving
ahead with this project. One the one side ifI build an efficient system to convey ail the water in the
future, I stand a very strong risk of creating erosion problems in Grapevine Creek. On the other
side, ill authorize the consultant to only design a system that will convey a 25-year storm I run the
risk of having street flooding along Bethel Road in those rare storm events that exceed a 25-year
frequency.
It is my recommendation that we design a drain~.~e system capable of conveying a 25-year
ultimate developed storm and work with the airport at some future date when they chose to
.develop the property in Coppell to tr~ to obtain some type of detention onsi~o It's important
to note that our system will convey the 100-year storm as long as the airport property remains
undeveloped. Also, if the airport constructs detention in the future, our system will still convey the
100-year storm. The only situation that reduces the capacity of our system would be if the airport
fully developed their property and released all the water without detention. With an undersized
system downstream, if and when the airport decides to develop, they will be in a predicament of
how to convey their water because our system would not be adequate to allow the release of all of
their water. So there is a possibility that they would be forced to have some type of onsite detention
just by virtue of the downstream system being undersized. To construct a system not in
conformance with the Subdivision Rule and Regulations requires a variance from City Council.
Therefore, I will take an agenda item on December 10, 2002 to request a variance.
If you have any questions, please feel free to contact me.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN" Page 3 of 4
Summary of Key Dates:
· February4,1999
· March 22, 1999
"Southwest Coppell Storm Water Management Master Plan" by HaIff &
Associates.
Sponsored by: The City ofCoppell, NCH, & Coppell Industrial NV
Legal opinion from Pete Smith that we cannot require DFW Airport to
install detention.
· April 13, 1999
Memo to Curtis Inglis, DFW Airport, providing summary of meeting
between Halff & Assoc., and Tracy Thompson, Doug Bryan & Mike Pyles
of DFW Airport and requesting clarification of drainage requirements on
airport property.
· May 11, 1999
February 13, 2001
Summary of reply from Curtis Inglis of DFW. Mr. Inglis spoke with
Kevin Cox and Gary Keane and Mr. Inglis stated that development of
airport property would be accomplished in responsible manner.
Entered into design con~xact with TranSystems Corporation for Bethel
Road and associated drainage.
· January 18, 2002 Received "Drainage Report Executive Summary" from TranSystems.
Report outlined necessity for detention on DFW Airport property.
· May 30, 2002
Received "Revised Draft Drainage Report for Regional Detention
Analysis / Bethel Road Improvements".
· July 18,2002
Met with representatives of DFW Airport and provided copy of"Revised
Draft Drainage Report for Regional Detention Analysis / Bethel Road
Improvements" for their review.
· October 11, 2002 Was informed that representatives of DFW Airport would not corrmnit to
any detention now or in the future.
· October 14, 2002
· October25, 2002
Requested evaluation of drainage system in Bethel Road if no detention
was provided by DFW Airport when they developed and our s~ystem was
constructed today as if there was no increase in runoff from DFW.
Received letter from TranSystems that system would convey
approximately a 25-year storm with ultimate development without
detention.
"CITY OF COPPELL ENGINEERING. EXCELLENCE BY DESIGN" Page 4 of 4
Mitigation Plan for Modification of Tributary G1
USACE Project No.: 200400181
APPENDIX B
FIGURES AND EXHIBITS
Alan Plummer Associates, Inc.
D:\OFFICE\8I 6\0201\Tributary Gl Mit Plan new.doc
~~ DALLAS COUNTY
~',',~I,,,,~- ~/~~
I Project Locat'°n [ 0/~
FIGURE 1
PROJECT LOCATION MAP
Boundary of Jurisdictional Determination
1,000 500 0 Feet
Figure prepared by: Jason votght
Rev, February 2, 2l~5
FIGURE 2 of 11
FIGURE 2
PROJECT VICINITY MAP
(FROM USGS TOPOGRAPHIC MAPS:
GRAPEVINE & IRVING, TX QUADRANGLES)
IIIII
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IlL
00'~ V.I.S ~INI1 HO.LYR
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avo~
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Mitigation Plan for Modification of Tributary G1
US~4 CE Project No.: 200400181
APPENDIX C
PRELIMINARY JURISDICTIONAL DETERMINATION
REPORT PREPARED BY
INTEGRATED ENVIRONMENTAL SOLUTIONS, INC.
DATED 26 NOVEMBER 2003
Alan Plummer Associates, Inc.
D:\OFFICE\816\0201\Tributary Gl Mil Plma_new.doc
Environmental SOlutions, Inc.
3100 li~lependence Pmkwa,/ I Suite 311 #320 I Plane, Texas 75075
T 972.562.7672 I F 972.562.7673
26 November 2003
Mr. Craig Bond, P.E.
TranSystems Corporation
3010 LBJ Freeway, STE 990
Dallas, Texas 75234
Re:
Waters of the United States Delineation and Section 404 Assessment
Bethel Road Drainage Improvements, City of Coppell, Texas
Tributary to Grapevine Creek Between Freeport Parkway and Coppall Road
N32o57.250' W97°00.543'
Dear Mr. Bond,
integrated Envtr' onmental Solutions, Inc. CIES) performed a survey for potential jurisdictional waters of the United
States on approximately 1,600 feet of a tributary to Grapevine Creek between Freeport Parkway and Coppeli Road
along Bethel Road in the City of Coppell, Dallas County, Texas (Attachment A, Figure 1). The delineation of
waters of the United States along this cmridor is provided in Attachment A, Figure 2. This delineation was
conducted to ensure compliance with Section 404 of the Clean Water Act (CWA) for the proposed improvements to
Bethel Road end associated drainage.
INTRODUCTION
Agencies that regulate impacts to the nation's water resources within Texas include the U.S. Army Corps of
Engineers (USACE), the U.S. Enviromnental Protection Agency, the U.S. Fish and Wildlife Service, and the Texas
Commission on Environmental Quality (TCEQ). Jurisdictional waters of the United States are protected under
guidelines outlined in Sections 401 and 404 of the CWA, in Executive Order 11990 CProtection of Wetlands), end
by the review process of the TCEQ. The USACE has the primary regulatory authority for enforcing Section 404
requirements for waters of the United States, including wetlands.
The definition of waters of the United States, in 33 Code of Federal Regulations (CFR) 328.3, includes waters such
as intrastate lakes, rivers, streams (including intermittent streams), mudflats, wetlands, sloughs, wet meadows, or
natural ponds and all impoundments of waters otherwise defined as waters of the United States. Also included are
wetlands adjacent to waters (other than waters that are themselves wetlands). The term adjacent is defined as
bordering, contiguous, or neighboring. Jurisdictional wetlands are a category of waters of the United States and
have been defined by the USACE as areas that are inundated or saturated by surface or groundwater at a frequency
and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions.
In January 2001, the U.S. Supreme Court in Solid Waste Agency of Northern Cook County (SWANCC) v. USACE,
changed the direction of federal regulation of isolated wetlands under the CWA by disallowing jurisdiction through
the "Migratory Bird Rule". Previously, the USACE assumed jurisdiction over isolated waters of the United States
based on its 1986 preamble stating that migratory birds used these habitats. The "Migratory Bird Rule" provided the
nexus to interstate commerce and thus protection under the CWA.
Mr. Cr~i~ Bo~,
Bethel Ro~d lmprovements
2~ Hovem~er
Page 2
The U§ACE has established guidance for determining between isolated and adjacent wetlands. Wetlands that are
bordering, contiguous, or neighboring another water of the United States (specifically one that flows into a
navigable water) is considered adjacent. Additionally, wetlands that are within the 100-year floodplain of another
water of the United States are also considered adjacent. All other wetlands would be considered isolated, and not
jurisdictional under the CWA.
METHODOLOGY
Prior to conducting fialdwork, the Soil Survey of Dallas County, Texas, the U.S. Geological Survey (USGS)
topographic map, and an aerial photograph of the proposed project corridor were studied to identify possible waters of
the United States and areas prone to wetland development. All potential waters of the United States were delineated in
the field by Rudi Reinecke of IES in accordance with the USACE guidelines on 20 November 2003.
Wetland determinations were performed on location using the methodology outlined in the Corps of Engineers
Wetland Delineation Manual (Environmental Laboratory 1987). The presence of jurisdictional wetlands is
determined by the positive indication of three criteria (i.e., hydrophytic vegetation, hydrology, and hydric soils).
Potential jurisdictional boundaries for non-wetland water resources were delineated in the field at the ordinary nigh
water mark (OHWIVO. The 33 CFR 328.3(e) defines OHWM as the line on the shore/bank established by flowing
and/ur standing water, marked by characteristics such as a clear, natural line impressed on the bank, erosion
shelving, changes in the character of soil, destruction of terrestrial vegetation, presence of litter and debris, or other
appropriate means that consider the characteristics of the surrounding ureas.
The areas of all potential waters of the United States were measured and their locations were noted on a field map of
the site (Attachment A, Figure 2). Photographs were also taken at representative points within the project corridor
(Attachment B).
RESULTS
The existing literature, soil survey and the USGS topographic map, provide conflicting data on where the
headwaters of the channel historically initiated. The soil survey illusa-ates the channel initiating nearly 1,500 feet
east of Coppell Road, which is downs~renm of this project. However, the USGS topographic map illustrates a blue
line for the tributary originating at Bethel Road, which is within the corridor. Additionally, the USGS topographic
map identified topographic relief throughout the corridor. This topographic relief identifies that there were drainage
patterns within the historical context of the map. The soil survey, USGS topographic map, and recent aerial
photographs do not illustrate any other waters of the United States within the corridor.
Soil Survey Map
Mr. Craig Bond P~E.
Bethel Road Improvements
26 November 2003
USGS Topographic Map
Page $
Field investigations focused on an
ephemeral drainage along Bethel Road
between Freeport Parkway and Coppell
Road. On-site surveys focused on
identifying the beginning of the OHWM as
defined by 33 CFR 328.3 (e). Historically,
the creek may have originated within thc
1,600 foot corridor; however, there is a
OHWM present throughout thc corridor.
This may be a result of the land use changes
fi.om prairie or cross timber pristine
communities to farmland to urban
structures. Each of these shifts increase the
runoffand potentially peak flows in streams,
which also result in the development of an
OHWM.
There is no evidence of a channel or
drainage feature west of Freeport Parkway.
Currently there is an OHWM throughout thc
corridor, initiating at Freeport Parkway. It
is lES' professional opinion that the
USACE would have jurisdiction over this
ephemeral drainage duc to the drainage
patterns illustrated on the USGS topographic map, the current OHWM, and thc hydrologic connection to larger
jurisdictional streams.
The limits of the waters of the United States provided in Attachment A, Figure 2 are based on field work conducted
on 20 November 2003. The field surveys included marking the OHWIVl with flagging; however, thc delineation was
recorded on a l-foot contour map. Thc tributary's OHWM ranged fi.om 2 to 10 feet in width throughout the
corridor. The tributary ranged in width depending upon the gradient of the channel. Locations where the tributary
had a steeper gradient, the tributary was between~e. Areas where the gradient was low, which
appeared to be areas associated with plunge pools, were between 6 and 10 feet wide. The ephemeral sfleam was
1,723 feet long (0.222 acre below the OHWM) with the drainage flowing from west to east. No wetlands or other
waters of thc United States were identified within the corridor.
Thc project corridor included a narrow riparian corridor that was no more than 25 feet on either side of the channel.
The riparian corridor was dominated by flees including cottonwood (Populus deltoides), black willow (Salix nigra),
hackberry ( Celtis laevigata), cedar elm ( Ulmus crassifolia), eastern red cedar (Juniperus virginiana), Dccan ( Carya
illinioensis), bitter pecan (Carya aquatica), boxeldar (Acer negundo), and green ash (Fraxinus pennsylvanica). The
riparian corridor tmderstory was dominated by annual ragweed (.4mbrosia trifida), Johnsongrass (Sorghum
halepense), Chinese ligustrum (Ligustrum sinense), waxleaf ligusflum (Ligustrum quihouO, silktree (Albizia
julibrissin), mustang grape (Vitis mustangensis), greenbriar (Smilax bona-nax), Japanese honeysuckle (Lonicera
japonica), and poison ivy (Toxicodendron radicans).
CONCLUSIONS
Thc only potential water of the United States within the project site was a single unnamed ephemeral channel
(u'ibuta~ to Grapevine Creek), which was approximately 1,723 linear feet and averaged between 2 and 10 feet wide
at the OHWM (0.222 acres total). Impacts to this channel would be subject to regulation by the USACE under
Section 404 of the CWA. Impacts to the channel resulting fi.om public road improvements may be authorized under
Nationwide Permit (P/WP) 14 -Linear Transportation Projects. Use of this NWP would require compliance with
all the conditions listed in Attachment C.
Mr. C~ Bom~ P.
26 No.tuber 2005
Page 4
Since the impacts would be greater than 0.1 acre to waters of the United States, the permittec must notify the
USACE under General Condition 13 of NWP 14. The notification should also include a mitigation plan that
includes how the project avoided, minimized, and compensated for impacts. Special consideration must be placed
on condition E, which states, "The width of the fill is limited to the minimum necessary for the crossing." In tho
notification submittal, the permittee will have to demonstrate that the improvements to Bethel Road cannot be
accomplished without impacting the natural channel beyond the footprint of the road improvements. It is also
important to understand that the USACE does have the power to apply discretionary interest in a project and require
the permit~ee to submit for an Individual Permit if they determine that the project does not have minimal impacts to
jurisdictional waters functions or values.
1ES appreciates the opportunity to work with you, TranSystems Corporation, and the City of Coppell on this project,
and hope we may be of assistance to you in the future. If you have any comments, questions, or concerns, please do
not hesitate to contact me at 972/562-7672 (rreinecke~iesolutionsinc.com).
Sincerely,
Integrated Environmental Solutions, Inc.
Rudi K. Reinecke
Wetland Ecologist
Attachments
Continental [
Anderson Gibson I {d
Grove I
Vista Ridge Mall
"~ Deforest Rd
; ¢, '
~-: :~- z. ~'~ ESandyLake~'t
0 1
Mapping Data: ESRI, 2002
Figure 1. Site Location
N
3 Kilometers
2 Miles
I
Wayside Dr
Hackberry Rd
t~°~al Ln
ATTACI-IMENT B
Representative Photographs
Photograph 29 Photograph 30
ATTACHMENT C
Nationwide Permit 14 -Linear Transportation Projects
5. Equipment. Heavy equipment working in wetlands must be placed on mats, or other measures must be taken to
minimize soil disturbance.
6. Regional and Case-By-Case Conditions. The activity must comply with any regional conditions that may have been
added by the Division Engineer (see 33 CFR 330.4(e)) and with any case spedific conditions added by the Corps or by
the state or tribe in its Section 401 Water Quality Certification and Coastal Zone Management Act consistency
determination. Note: Statewide Regional Conditions have been added for acOvifles within Texas.
7. Wild and Scenic Rivers. No activity may occur/n a component of the National Wild and Scenic River System; or in a
fiver officially designated by Congress as a "study fiver" for possible inclusion in the system, while the river is/n an
official study status; unless the appropriate Federal agency, with direct management responsibility for such river, hes
determined/n wfiting that the proposed activity will not adversely affect the Wild and Scenic River designation, or study
status. Information on Wild and Scenic Rivers may be obtained from the appropriate Federal land management agency in
the area (e.g., National Park Service, U.S. Forest Service, Bureau of Land Management, U.S. Fish end Wildlife Service).
8. Tribal Rights. No activity or its operation may impair reserved tribal fights, including, but not limited to, reserved
water fights and treaty fishing and hunting fights.
9. Water Quality. (a) In certain states and tribal lends an individual 401 Water Quality Certification must be obtained or
waived (See 33 CFR 330.4(c)).
(b) For NWPs 12, 14, 17, 18, 32, 39, 40, 42, 43, and 44, where the state or tribal 401 certification (either genetically or
individually) does not require or approve water quality management measures, the permittee must provide water quality
management measures that will ensure that the authorized work does not result in more than minimal degradation of
water quality (or the Corps determines that compliance with state or local standards, where applicable, will eusum no
more than minimal adverse effect on water quality). An important component of water quality management includes
stormwater management that minimizes degradation of thc downstream aquatic system, including water quality (refer to
General Condition 21 for stormwater management requirements). Another important component of water quality
management is the establishment and maintenance of vegetated buffers next to open waters, including streams (refer to
General Condition 19 for vegetated buffer requirements for the NWPs).
This condition is only applieabhi to projects that have the potential to affect water quality. While appropriate measures
must be taken, in most cases it is not necessary to conduct detailed studies to identify suer measures or to require
monitoring.
10. Coastal Zone Management. In certain states, an individual state coastal zone management consistency concurrence
must be obtained or waived (see 33 CFR 330.4(d)).
11. Endangered Speei~. (a) No activity is authorized under any NWP which is likely to jeopardize the continued
existence ora threatenea or endangered species or a species proposed for such designation, as identified under the
Federal Endangered Species Act (ESA), or which will destroy or adversely modify the critical habitat of such species.
Non-federal permittees shall notify the Distfict Engineer if any listed species or designated critical habitat might be
affected or is in the vieiniW of the project, or is located in the designated critical habitat and shall not begin work on the
activity until notified by the Dis~'ict Engineer that the requirements of the ESA have been satisfied and that the activity
is authorized. For activities that may affect Federally-listed endangered or threatened species or designated critical
habitat, the notification must include the name(s) of the endangered or threatened species that may be affected by the
proposed work or that utilize the designated critical habitat that may be affected by the proposed work. As a result of
formal or informal consultation with the FWS or NMFS the Disaict Engineer may add species-specific regional
endangered species conditions to the NWPs.
(b) Authorization of an activity by a NWl' does not authorize the "take" of a threatened or endangered species as
defined under the ESA. In the absence of separate authorization (e.g., an ESA Section 10 Permit, a Biolagieal Opinion
with "incidental take" provisions, etc.) from the USFWS or the NMFS, both lethal and non-lethal "takes" of protected
species are in violation of the ESA. Information on the location of threatensd and endangered species end their critical
2
habitat can be obta/ned directly from the offices of thc USFWS and NMFS or their world wide web pages at
http://www.f~vs.gov/rgendspp/cndspp.html and http://www.nmfs.noaa.gov/prot_res/overview/cs.hOni ruspectivcly.
~No activity which may affect historic properties listed, or eligible for listing, in the National
Keg~star of Historic Places is authorized, until the District Bngineer has complied with the provisions of 33 CFR part 325,
Appendix C. Thc prospective permittee most notify the District Enginecr if the author/zed activity may affect any historic
properties listed, determined to be cligiblc, or which thc prospective permittee has reason to believe may be eligible for
listing on the National Register of Historic Places, and shall not begin the activity until notified by the District Engineer
that the requirements of the National Historic Preservation Act have been satisfied and that thc activity is authorized.
Information on thc location and existence of historic reanurcas can be obtaincd from the State Historic Preservation
Office and the National Register of Historic Places (see 33 CFR 330.4(g)). For activities that may affect historic properties
listed in, or eligible for listing in, the National Register of His/or/c Places, the notification must state which historic
property may be affected by thc proposed work or include a vicinity map indicating the location of the historic property.
13. Notification.
(a) Timing; where required by the terms of the NW'P, the prospective permittee must notify the District Engineer with a
preconstruction notification (PC'N) as early as possible. The District Engineer must determine if the notification is
complete within 30 days of the date of reeaipt and can request additional information necessary to make thc PCN
complete only once. However, if the prospective permittee does not provide all of the requested information, then the
District Engineer will notify the prospective permittec that thc notification is still incomplete and thc PCN review process
will not commence until all of the requested information has been received by the District Engineer. The prospective
permittee shall not begin thc activity:
(1) Until notified in writing by the District Engineer that the activity may proceed under the NWP with any special
conditions imposed by the District or Division Engineer; or
(2) If notified in writing by the District or Division Engineer that an Individual Permit is required; or
(3) Unless 45 days have passed from the District Engineer's receipt of the complete notification and the prospective
permitt~c has not received written notice from the District or Division Engineer. Subsequently, the permittee*s right to
proceed under thc NWP may be modified, suspended, or revoked only in accordance with the procedure set forth in 33
CFR 330.5(o')(2).
· Co) Contents of Notification: The notification must be in writing and include the following information:
(1) Name, address and telephone numbers of the prospective permittce;
(2) Location of the proposed project;
(3) Brief deseription of the proposed project; the project's pmpoee; direct and indirect adverse environmental effects
the project would cause; any other NWP(s), Regional General Permit(s), or Individual Permit(s) used or intended to be
used to authorize any part oftbe proposed project or any related activity. Skctohes should be provided when necessary
to show that thc activity complies with the terms of the NWP (Sketches usually clarify the project and when provided
result in a quicker decision.);
(4) For NWPs 7, 12,{~18, 21, 34, 38, 39, 40, 41, 42, end 43, the PCN must also include a delineation of affected special
aquatic sites, including wetlands, vegetated shallows (e.g., submerged aquatic vegetation, seagrass beds), and riffle and
pool complexes (see paragraph 13(0);
(5) For NWP 7 (Ouffall Stmcturas and Maintenance), the PCN must include information regarding the original design
capacities arid configurations of those areas of the facility where maintenance dredging or excavation is proposed;
(6) For NWP 14 (Linear Transportation Projects), the PCN must include a compensatory mitigation proposal to offset
~_rm anan~t losaes of, .wate, rs,, of,the U,S and a statement dusc, ribingi how temporary losses ~f waters ofth~ US vail
~m~.~..~i.r~, to the ziia.umum Cxh:nt [~'~¢ticable: ..... , -
(7) For NWP 21 (Surt'aee Coal Mining Ac-fivities), the PCN must include an Office of Surface Mining (OSM) or state-
approved mitigation plan, if applicable. To be authorized by this NWl>, the District Engineer must determine that the
activity complies with the terms and conditions of the ~ and that the adverse environmental effects are minimal both
individually and cumulatively and must notify the project sponsor of this determination in writing;
(8) For NWP 27 (Sm=am and Wetland Restoration Activities), the PC'N must include documentation of the prior
condition of the site that will be reverted by the permittec;
(9) For NWP 29 (Single-Family Housing), the PCN must also include:
3
General Condition 13. A letter containing the requisite information may also be used.
(d) Distrct Engineer's Decision: In reviewing the PC'N for the proposed activity, the Distrct Engineer will determine
wh~ther the activity authorized by the NWP will result in more than minimal individual or cumulative adverse
environmental effects or may be contrary to the public interest. The prospective permittee may submit a proposed
mitigation plan with the PCN to expedite the process. The Distrct Engineer will consider any proposed compensatory
mitigation the applicant has included in the proposal in determining whether the net adverse environmental effects to the
aquatic environment of the proposed work are minimal. If the District Engineer determines that the activity complies with
the terms and conditions of the NWP and that the adverse effects on the aquatic environment a~ minimal, aRer
considering mitigation, the District Engineer will notify the permittee and include any conditions the District Engineer
deems necessary. The District Engineer must approve any compensatory mitigation proposal before the permittee
commences work. If the prospective permittee is required to submit a compensatory mitigation proposal with the PC'N,
the proposal may be either conceptual or detailed. If the prospective permittee elects to submit a compensatory
mitigation plan with the PCN, the District Engineer will expeditiously review the proposed compensatory mitigation plan.
The District Engineer must review the plan within 45 days of receiving a complete PCN and determine whether the
conceptual or specific proposed mitigation would ensure no more than minimal adverse effects on the aquatic
environment. If the net adverse effects of the project on the aquatic environment (after consideration of the
compensatory mitigation proposal) are determined by the District Engineer to be minimal, the District Engineer will
provide a timely written response to the applicant. The response will state that the project can proceed under the terms
and conditions of the NWP.
ffthe District Engineer determines that the adverse effects of the proposed work are more than minimal, then the
District Engineer will notify the applicant either:. (1) That the project does not qualify for authorization under the NWP
and instruct the applicant on the procedures to seek authorization under an Inthwdual Permit; (2) that the project is
authorized under the NWP subject to the applicant's submission cfa mitigation proposal that would reduce the adverse
effects on the aquatic environment to the minimal level; or (3) that the project is authorized under the NWP with specific
modifications or conditions. Where the District Engineer determines that mitigation is required to ensure no more than
minimal adverse effects occur to the aquatac environment, the activity will be authorized within the 45-day PCN period;
The authorization will include the necessary conceptual or specific mitigation or a requirement that the applicant submit a
mitigation proposal that would reduce the adverse effects on the aquatic environment to the minimal level. When
eeneeptual mitigation is included, or a mitigation plan is required under item (2) above, no work in waters of the US will
occur until the Distret Engineer has approved a specific mitigation plan.
(e) A~ency Coordination: The District Engineer will consider any comments from Federal and state agencies
concermng the proposed activity's eomplianca with the terms and eonditiuns of the NWPs end the need for mitigation to
reduce the project's adverse environmental effects to a minimal level.
For activities requiring notification to the District Engineer that result in the loss of greater than l/2-acre of waters of
the US, the Distrct Engineer will provide immediately (e.g., via facsimile transmission, overnight mail, or other
expeditious manner) a copy to the appropriate Federal or state ofliees CUSFWS, state natural resource or water quality
agency, EPA, State Historic Preservation Officer (SI/PO), end, if appropriate, the NMFS). With the exception of NWP 37,
these agencies will then have 10 calendar days from the date the material is transmitted to telephone or fax the District
Engineer notice that they intend to provide substantive, site-specific comments. If so contacted by an agency, the
District Engineer will wait an additional 15 calendar days before making a decision on the notification. The District
Engineer will fully consider agency eormnents received within the specified time frame, but will provide no response to
the resource agency, except as provided below. The District Engineer will indicate in the administrative record associated
with each notification that the resource agencies' concerns were ' ' -
considered. As reqrured by section 305(b)(4)(B) of the
Magnusun-Stevens Fishery Conservation and Management Act, the Dis~ct Engineer will provide a response to NMFS
within 30 days cie receipt otany Essential Fish Habitat conservation recommendations. Applicants are encouraged to
provide the Corps multiple copies of notificalions to expedite agency notification.
(f) Wetland Delineations: Wetland delineations must be prepared in accordance with the current method required by
the Corps (For NWP 29 see paragraph Co)(9)(iii) for parcels less than (1/4-acre in size). The permittee may ask the Corps
to delineate the special aquatic site. There may be some delay if the Corps does the delineation. Furthermore, the 4$~lay
period will not start until the wetland delineation has been completed and submitted to the Corps, where appropriate.
14. Compliance Cerflllcaflon. Every permittee who has received NWP verification from the Corps will submit a signed
5
certification regarding the completed work and any required mitigation. The certification will be forwarded by the Corps
with the authorization letter and will include:
(a) A statement that the authorized work was done in accordance with the Corps authorization, including any general
or specific annditions;
(b) A statement that any required mitigation was completed in accordance with the permit conditions; and
(e) The signature of the permittee certifying the completion of the work and mitigation.
15. Use of Multiple Nationwide Permits. The use of more than one NWP for a single and complete project is prohibited,
except when the acreage loss of waters oftha US authorized by the NWPs does not exceed the acreage limit of the NWP
with the highest specified acreage limit (e.g. if a road crossing over tidal waters is constructed under NWP 14, with
associated bank stabilization authorized by NWP 13, the maximum acreage loss of waters of the US for the total project
cannot exceed l/3-acre).
16. Water Supply Intakes. No activity, including structures and work in navigable waters of the US or discharges of
dredged or fill material, may occur in the proximity of a public water supply intake except where the activity is for repair of
the public water supply intake structures or adjacent bank stabilization.
17. Shellfish Bads. No activity, including structures and work in navigable waters oftha US or discharges of'dredged or
fill material, may occur in areas of cuneentrated shellfish populations, unless the activity is dire¢fly related to a shellfish
harvesting activity authorized by NWP 4.
18. Suitable Material. No activity, including structures and work in navigable waters of the US or discharges of dredged
or fill material, may consist of unsuitable material (e.g., lrash, debris, car bodies, asphalt, etc.) and material used for
construction or discharged must be free from toxic pollutants in toxic amounts (see section 307 of the CWA).
19. Mitigation. The District Engineer will ennsider the factors discussed below when determining the acceptability of
appropriate and practicable mitigation necessary to offset adverse effects on the aquatic environment that are more than
minimal
(a) The project must be designed and consiructed to avoid and minimize adverse effects to waters of the US to the
maximum extent practicable at the project site (i.e., on site).
(b) Mitigation in all its forms (avoiding, minimizing, rectifying, reducing or compensating) will be required to the extent
necessary to ensure that the adverse effects to the aquatic environment are minimal.
(e) Compensatory mitigation at a minimum one-for-ona ratio will be required for all wetland impacts requiring a PCN,
unless the District Engineer determines in writing that some other form of mitigatiun would be more environmentally
appropriate and provides a project-specific waiver of this requirement. Consistent with National policy, the District
Engineer will establish a preference for restoration of weflands as compensatory mitigation, with preservation used only
in exceptional cimumstanees.
(d) Compensatory mitigation (i.e., replacement or substitution of aquatic resources for those impacted) will not be used
to increase the acreage losses allowed by the acreage limits of some of the NWPs. For example, l/4-acre of wetlands
cannot be created to change a 3/4-acre loss of wetlands to a I/2-aere loss associated with NWP 39 verification. However,
l/2-acre of created wetlands can be used to Educe the impacts ora 1/2-acre loss of wctlands to the minimum impact level
in order to meet the minimal impact requirement associated with NWPs.
(e) To be practicable, the mitigation must be available and capable of being done eunsidering costs, existing
technology, and logistics in light of the overall project purposes. Examples of mitigation that may be appropriate and
practicable include, but are not limited to: reducing the size of the projsot; establishing and maintaining wetland or
upland vegetated buffers to protect open waters such as streams; and replacing losses of aquatic resource functions and
values by creating, restoring, enhancing, or preserving similar functions and values, preferably in the same watershed.
(f) Compensatory mitigation plans for projects in or near streams or other open waters will normally include a
requirement for the establishment, maintenance, and legal protection (e.g., easements, deed res~ctiuns) of vegetated
buffers to open waters. In many cases, vegetated buffers will be the only compensatory mitigation required. Vegetated
buffers should consist of native species. The width oftbe vegetated buffers required will address documented water
quality or aquatic habitat loss concerns. Normally, the vegetated buffer will be 25 to 50 feet wide on each side of the
6
including wetlands adjacent to such waters. Discharges of dredged or fill materials into waters of the US may be
authorized by the above NWPs in National Wild and Scenic Rivers if the activity complies with General Condition 7.
Further, such discharges may be authorized in designated critical habitat for Federally listed threatened or endangered
species if the activity complies with General Condition 11 and the USFWS or the NMFS has concurred in a determination
of complisuce with this condition.
(b) For NWPs 3, 8, 10, 13, 15, 18, 19, 22, 23, 25, 27, 28, 30, 33, 34, 36, 37, and 38, notification is required in accordance
with General Condition 13, for any activity proposed in the designated critical resource waters including wetlands
adjacent to those waters. The District Engineer may authorize activities under these NWPs only after it is dcterr~med that
~he impacts to the critical resource waters will be no mom than minimal.
26. Fills Within 100-Yeur Floodplains. For purposes of this General Condition, 100-year floodplains will be identified
through the existing Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Maps or FEMA-
approved local floodplain maps.
(a) Discharges in Floodplain; Below Headwaters. Discharges of dredged or fill material into waters of the US within the
mapped 100-year floodplain, below headwaters (i.e. five cfa), resulting in permanem above-grade fills, are not authorized
by NWPs 39, 40, 42, 43, and 44.
(b) Discharges in Floodway; Above Headwaters. Discharges of dredged or fill material into waters of thc US within the
FEMA or locally mapped floodway, resulting in permanent above-grade fills, are not authorized by NWPs 39, 40, 42, and
44.
(c) The permittce must comply with any applicable FEMA-approved state or local floodplain management
requirements.
27. Construction Period. For activities that have not been verified by the Corps and the project was commenced or under
contract to commence by the expiration date of the NWP (or modification or revocation date), the work must be
completed within 12~months after such date (including any modification that affects the project).
For activities that have been verified and the project was commenced or under contract to commence within the
verification period, the work must be completed by the date determined by the Corps.
For projects that have been verified by the Corps, an extension of a Corps approved completion date maybe requested.
This request must be submitted at least one month before the previously approved completion date.
FU~I'HER INFORMATION
1. District Engineers have authority to determine if an activity complies with the terms and conditions of an NWP.
2. NWPs do not obviate the need to obtain other Federal, state, or local permits, approvals, or authorizations required by
law.
3. NWPs do not grant any property rights or exclusive privileges.
4. NWPs do not authorize any injary to the propen'y or rights of others.
5. NWPs do not authorize interference with any exisfing or proposed Federal project.
DEFINITIONS
Best Management Practices (8l~lPs~ BMPs are policies, practices, procedures, or structures implemented to mitigate
thc adverse environmental cffect~ on surface water quality resulting from development. BMPs arc categorized as
structural or non-structural. A BMP policy may affect the limits on a development.
Compematury Mitigation: For purposes of Section 10/404, compensatory mitigation is the restoration, creation,
enhancement, or in exceptional circumstances, preservation of wetlands and/or other aquatic resources for the propose
of compensnting for unavoidable adverse impacts which remain afier all appropriate and practicable avoidance and
minhniza~on has been achieved.
Creation: Thc establishment of a wetland or other aquatic resource where one did not formerly exist.
Enhancement: Activities conducted in existing wetlands or other aquatic resources that increase one or more aquatic
functions.
Ephemeral Stream: An ephemeral stream has flowing water only during and for a short duration afier, precipitation
$
events in a typical year. Ephemeral stream beds are located above the water table year-round. Groundwater is not a
source of water for the stream. Runoff fxom rainfall is the primary source of water for stream flow.
Farm Tract A unit of contiguous land under one ownership that is operated as a farm or part of a farm.
F/ood Fringe: That portion of the 100-year floodplain outside of the floodway (often referred to as "floodway fringe").
Floodway:. The area regulated by Federal, state, or local requirements to provide for the discharge of the base flood so
the cumulative increase in water surface elevation is no more than a designated amount (not to exceed one foot as set by
the National Flood Insurance Program) within the 100-year floodplain.
Independent Utility: A test to determine what constitutes a single and complete project in the Corps regulatory
program. A project is considered to have independent utility if it would be const~ructed absent the construction of other
projects in the project area. Portions of a multi-phase project that depend upon other phases of the project do not have
independent utility. Phases of a project that would be consffucted even if the other phases were not built can be
considered as separate single and complete projects with independent utility.
l~terrmtt~nt S~'eam. An lntermtttent stream has flowing water dunng certain times of the year, when groundwater
provides water for stream flow. During dry periods, intermittent streams may not have flowing water. Rune ff from rainfall
is a supplemental source of water for sffeam flow.
Loss of Watera of the US: Waters of thc US that include thc filled area and other waters that arc permanently
adversely affected by flooding, excavation, or drainage because of the regulated activity. Permanent adverse effects
include permanent above-grade, at-grade, or below-grade fills that change an aquatic area to dry land, increase the
bottom elevation ora waterbody, or change the use ofa waterbody. The acleage of loss of waters of the US is the
threshold measurement of the impact to existing waters for determining whether a project may qualify for an NWP; it is
not a net threshold that is calculated al~er considering compensatory mitigation that may be used to offset losses of
aquatic functions and values. The loss of stream bed includes the hnear feet of stream bed that is filled or excavated.
Impacts to ephemeral streams are not included in thc linear foot measurement of loss of stream bed for the purpose of
determining compliance with the linear foot limits of NWPs 39, 40, 42, and 43. Waters of the US temporarily filled,
flooded, excavated, or drained, but restored to preconstruction contours and elevations after construction, are not
included in the measurement of loss of waters of the US.
Nol~-tidal Wetland: A non-tidal wetland is a wetland (i.e., a water of the IJS) that is not subject to the ebb and flow of
tidal waters. The definition of a wetland can be found at 33 CFR 328.3(b). Non-tidal wetlands contiguous to tidal waters
are located landward of the high tide line (i.e., spring high tide line).
Open Water: An area that, during a year with normal patterns of precipitation, has standing or flowing water for
sufficient duration to establish an ordinary high water mark. Aquatic vegetation within the area of standing or flowing
water is either non-emergent, sparse, or absent. Vegetated shallows are considered to be open waters. The term ·'open
wW~er" includes rivers, streams, lakes, and ponds. For the purposes of the NWPs, this term does not include ephameral
ors.
Perennial Stream: A perennial stream has flowing water year-round during a typical year. Thc water table is located
above the stream bed for most of the year. Groundwater is the primary source of water for stream flow. Runoff bom
rainfall is a supplemental source of water for stream flow.
P~rmanent Above-grade Fill: A discharge of dredged or fill material into waters of the US, including wetlands, that
results in a substantial increase in ground elevation and permanently converts part or all of the waterbody to dry land.
Structural fills authorized by NWI~s 3, 25, 36, etc. are not included.
· Pre~ervalion: The protection of ecologically important wetlands or other aquatic resources in perpetuity through the
implementation of appropriate legal and physical mechanisms. Preservation may include protection of upland ar~as
adjacent to wetlands as necessary to ensure protection and/or enhancement of the overall aquatic ecosystem·
R~teraltion: Re-establishment of wetland and/or other aquatic resource characteristics and function(s) at a site where
they have ceased to exist, or exist in a substantially degraded state.
Riffle and Pool Complea: Riffle and pool complexes arc special aquatic sites under the 404(b)(1 ) Guidelines. Riffle and
pool complexes sometimes characterize steep gradient sections of streams. Such stream sections are recoguizablc by
their hydraulic characteristics. The rapid movement of water over a course substrate in riffles results in a rough flow, a
turbulent surface, and high dissolved oxygen levels in the water. Pools are deeper areas associated with riffles. A sbwer
stream velocity, a streaming flow, a smooth surface, and a finer substrate characterize pools.
Single and Complete Project The term "single and complete project" is defined at 33 CFR 330.2(i) as the total project
proposed or accornplished by one owner/developer or partnership or other association of owners/developers (see
9
definition of independent utility). For linear projects, the "single and complete project" (i.e., a single and complete
crossing) will apply to each crossing of a separate water of the US (i.e., a single waterbody) at that location. An
exception is for linear projects crossing a single waterbody several times at separate and distant locations: each crossing
is considered a single and complete projent. However, individual channels in a braided stream or fiver, or individual arms
cfa large, irregularly shaped wetland or lake, etc., are not separate waterbodies.
Stormwater Management: Stormwater management is the mechanism for controlling stormwater runoff for the
purposes of reducing downstream erosion, water quality degradation, and flooding and mitigating the adverse effects of
changes in land use on the aquatic environment.
Sturmwater Management Facilities: Stormwater management facilities are those facilities, including but not limited to,
stormwater retention and detention ponds and BMY's, which retain water for a period of time to control runoff and/or
improve the quality (i.e., by reducing the concentration of nutriants, sediments, hazardous substances and other
pollutants) of stormwater runoff.
Stream Bed: The substrate of the stream channel between the ordinary high water marks. The substrate may be
bedrock or inorganic particles that range in size from clay to boulders. Wetlands contiguous to the stream bed, but
outside of the ordinary high water marks, are not considered part of the stream bed.
Stream Channelization: The manipulation cfa stream channel to increase the rate of water flow through the stream
channel. Manipulation may include deepening, widening, straightening, armoring, or other activities that change the
stream cross-section or other aspects of stream channel geometry to increase the rate of water flow through the stream
channel. A channelized stream remains a water of the US, despite the modifieatiens to increase the rate of water flow.
Tidal Wetland: A tidal wetland is a wetland (i.e., water of the US) that is inundated by tidal waters. The de fruitions of a
wetland and tidal waters can be found at 33 CFR 328.3(b) and 33 CFR 328.3(f), respectively. Tidal waters rise and fall in a
predictable and measurable rhythm or cycle due to the gravitational pulls of the moon and sun. Tidal waters end where
the rise and fall of the water surface can no longer be practically measured in a predictable rhythm due to masking by
other waters, wind, or other effects. Tidal wetlands are located chanaelward of the high tide line (i.e., spring high tide
line) and are inundated by tidal waters two times per lunar month, during spring high tides.
Vegetated Buffer: A vegetated upland or wetland area next to rivers, streams, lakes, or other open waters which
separates the open water from developed areas, including agricultural land. Vegetated buffers provide a variety of
aquatic habitat functions and values (e.g., aquatic habitat for fish and other aquatic organisms, moderation of water
temperature changes, and detritus for aquatic food webs) and help improve or maintain local water quality. A vegetated
buffer can be established by maintaining an existing vegetated area or planting native trees, shrubs, and herbaceous
plants on land next to open-watars. Mowed lawns are not considered vegetated buffers because they provide little or no
aquatic habitat functions and values. The establishment and maintenance of vegetated buffers is a method of
compensatory mitigation that can be used in conjunction with the restoration, creation, enhancement, or preservation of
aquatic habitats to ensure that activities authorized by NWPs result in minimal adverse effects to the aquatic
anvireament. (See General Condition 19.)
Vegetated Shallows: Vegetated shallows are special aquatic sites under the 404(b)(1) Guidelines. They are areas that
are permanently inundated and under normal circumstances have rooted aquatic vegetation, such as seagrasses in
marine and estuarine systems and a variety of vascular rooted plants in freshwater systems.
Waterbody: A waterbody is any area that in a normal year has water flowing or standing above ground to the extent
that evidence of an ordinary high water mark is established. Wetlands contiguous to the waterbody are considered part
of the watarbody.
l0
Mitigation Plan for Modification of Tributary G1
USA CE Project No.: 200400181
APPENDIX D
MAPPED SOIL TYPES IN PROJECT AREA
Alan Plummer Associates, Inc.
D:\OFFICE\816\0201\Tributary Gl Mit Plan new.doc
SOIL SERIES DATA
WILSON SERIES
The Wilson series consists of very deep, moderately well drained, very slowly permeable
soils that formed in alkaline clayey sediments. These soils are on nearly level to gently
sloping stream terraces or terrace remnants on uplands. Slopes are mainly less than 1
percent but range from 0 to 5 percent.
TAXONOMIC CLASS: Fine, smectitic, thermic Oxyaquic Vertic Haplustalfs
TYPICAL PEDON: Wilson silt loam--cropland. (Colors are for moist soil unless
otherwise stated.)
Ap--0 to 5 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; weak fine
granular structure; massive when dry; very hard, firm, sticky and plastic; common fine
roots; moderately acid; abrupt wavy boundary. (3 to 10 inches thick)
Bt--5 to 20 inches; very dark gray (10YR 3/1) silty clay, gray (10YR 5/1) dry; moderate
medium angular blocky structure; extremely hard, very firm, very sticky and very plastic;
few fine roots; few fine pores; thin continuous clay films 1/2 unit of value darker than
interior of peds; vertical cracks 1/2 inch wide are filled with material from the Ap
horizon; slightly acid; gradual wavy boundary. (10 to 20 inches thick)
Btssgl--20 to 32 inches; grayish brown (2.5Y 5/2) silty clay, light brownish gray (2.5Y
6/2) dry; moderate medium angular blocky structure; extremely hard, very firm, very
sticky and very plastic; few fine roots; few fine pores; few slickensides; few medium
pressure faces; thin continuous clay films on surface of peds; vertical cracks 1/4 inch
wide partly filled with material from above; few fine crystals of gypsum; few fine
calcium carbonate concretions; slightly alkaline; diffuse wavy boundary.
Btssg2--32 to 65 inches; grayish brown (2.5Y 5/2) silty clay, light brownish gray (2.5Y
6/2) dry; weak coarse angular blocky structure; extremely hard, very firm, very sticky
and very plastic; few fine roots; few fine pores; few slickensides; patchy clay films on
surface of peds; common fine crystals of gypsum; few fine masses of calcium carbonate;
slightly alkaline; gradual smooth boundary. (combined Btss subhorizons are 25 to 60
inches thick)
BCkss--65 to 80 inches; olive gray (5Y 5/2) silty clay, light gray (5Y 7/2) dry; weak
coarse angular blocky structure; extremely hard, very firm, very sticky and very plastic;
few fine roots; few fine pores; few slickensides; few coarse masses of calcium carbonate;
few small fragments of clay; very slightly effervescent; moderately alkaline.
TYPE LOCATION: Kaufman County, Texas; 4 miles southeast of the intersection of
Texas Highway 34 and U. S. Highway 175 in Kaufman, 0.15 mile northeast and 0.2 mile
southeast of intersection of county road and U. S. Highway 175, 150 feet south~vest in
field.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80
inches. The weighted average clay content of the upper 20 inches of the argillic horizon
ranges from 35 to 50 percent. When dry, cracks at least 1/4 inch wide extend from the top
of the argillic horizon through a thickness of 12 inches or more within the upper 50
inches of the soil. Slickensides and/or wedged-shaped aggregates and pressure faces
range from few to common and begin at a depth of 14 to 26 inches. Linear extensibility is
greater than 2.5 inches (6 cm) within 40 inches (100 cm) of the soil surface. COLE
ranges from 0.07 to 0.10 in the upper 50 inches of the argillic horizon. The surface layer
is variable in thickness with a series of micro crests and troughs in the Bt horizon that
range from 4 to about 20 feet apart. Redoximorphic features are contemporary in the
upper Btl horizon and are mainly relic in the lower part of the Bt horizon. The soil does
not have aquic soil conditions in the upper 20 inches in most years.
The A horizon is less than 10 inches thick in more than 50 pement of the pedon, but it is
as much as 15 inches thick in some subsoil troughs. It has hue of 10YR or 2.5Y, value of
3 to 5, and chroma of 1 or 2. Texture is loam, silt loam, silty clay loam, clay loam or their
gravelly counterparts. Siliceous pebbles and small cobbles range from 0 to 35 percent. It
is massive and hard or very hard when dry but is soft or friable with structure when
moist. Some pedons have a thin E horizon in subsoil troughs. Reaction ranges from
moderately acid to neutral.
The Bt horizon has hue of 10YR or 2.5Y, value of 2 to 4, and chroma of 1 or less.
Texture is clay loam, silty clay loam, silty clay, or clay. Some pedons have iron
concentrations in shades of brown or yellow that range from few to common. Siliceous
pebbles range from 0 to about 15 percent by volume. Reaction ranges from slightly acid
to slightly alkaline.
The Btss horizon has hue of 10YR to 5Y, value of 3 to 7, and chroma of 2 or less. Iron
concentrations in shades of yellow, brown or olive range from none to common. Texture
is commonly silty clay or clay and less commonly silty clay loam or clay loam. Reaction
ranges from moderately acid to slightly alkaline and is typically noncalcareous.
The BCk or BC horizon has colors in shades of gray or brown. Redoximorphic features
of these colors and in other shades of yellow, red or olive range from few to many.
Texture is clay loam, silty clay loam, silty clay, or clay. Some pedons have fragments or
thin strata of shale or marl. These materials make up less than 35 percent of the matrix.
Reaction ranges from neutral to moderately alkaline. Concretions and masses of calcium
carbonate range from none to common.
The C horizon, where encountered, is shale or marl or stratified layers of shale, marl and
clay.
COMPETING SERIES: There are no competing series. Similar soils are the Dacosta~
Herty, Lufkim Mabank, and Steedham series. Dacosta soils have a mollic epipedon and
are members of the hyperthermic family. Herty, Lufkin and Mabank soils have an abrupt
texture change between the A and Bt horizon. In addition, Herty soils are in the udic
moisture regime. Steedham soils have sola from 20 to 40 inches thick, and are well
drained.
GEOGRAPHIC SETTING: Wilson soils are on nearly level to gently sloping terraces
or remnants of terraces. Slope gradients are 0 to 5 percent but dominantly less than 1
percent. The soil formed in alkaline clayey alluvium. Mean annual temperature ranges
from 64 to 70 degrees F., and mean annual precipitation ranges from 32 to 45 inches.
Frost free days range from 220 to 270 days and elevation ranges from 250 to 700 feet.
Thomthwaite P-E indices from 50 to 70.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonham, Burleson,
Crockett, Houston Black, Lufkin, Mabank, and Normangee series. Bonham soils have
mollic epipedons. Burleson soils are on similar positions. Burleson and Houston Black
soils are clayey to the surface and have slickensides (Vertisols). Crockett and Normangee
soils have Bt horizons with chroma of more than 2. Bonham, Houston Black, Crockett
and Normangee soils are on slightly higher positions above Wilson. Lufkin soils are on
similar or slightly lower concave positions. Mabank soils are on similar positions.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very
slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, and high
on 3 to 5 percent slopes. Very slow internal drainage. The soil is seasonally wet and is
saturated in the surface layer and upper part of the Bt horizon during the winter and
spring seasons for periods of 10 to 30 days.
USE AND VEGETATION: Wilson soils are cropped to cotton, sorghums, small grain,
and corn. Many areas are now idle or are used for unimproved pasture. Original
vegetation was tall prairie grasses, mainly andropogon species, and widely spaced motts
of elm and oak trees. Most areas that are not cropped have few to many mesquite trees.
DISTRIBUTION AND EXTENT: Mainly in the Blackland Prairies of Texas, with
small areas in Oklahoma. The soil is extensive, probably exceeding 1,000,000 acres.
AXTELL SERIES
The Axtell series consists of very deep, moderately well drained, very slowly permeable
soils on Pleistocene terraces. The soil formed in slightly acid to alkaline clayey
sediments. Slopes are dominantly 0 to 5 percent, but range up to 12 percent.
TAXONOMIC CLASS: Fine, smectitic, thermic Udertic Paleustalfs
TYPICAL PEDON: Axtell very fine sandy loam - post oak savannah. (Colors are for
dry soil unless otherwise stated.)
A--0 to 3 inches; brown (10YR 5/3) very fine sandy loam, dark brown (10YR 4/3) moist;
weak fine subangular blocky structure; very hard, very friable; many fine and coarse
roots; common fine pores; slightly acid; clear smooth boundary. (3 to 10 inches thick)
E--3 to 8 inches; very pale brown (10YR 7/3) very fine sandy loam, pale brown (10YR
6/3) moist; weak fine subangular blocky structure; hard, very friable; many fine and
coarse roots; common fine pores; strongly acid; clear smooth boundary. (0 to 9 inches
thick)
Bt--8 to 21 inches; reddish yellow (5YR 6/6) clay loam, yellowish red (5YR 5/6) moist;
weak medium and coarse angular blocky structure; extremely hard, very firm; sticky and
plastic; many fine and coarse roots between peds; few fine pores; few pressure faces;
common medium distinct light brownish gray (10YR 6/2) iron depletions and few
medium distinct strong brown (10YR 5/6) masses of iron accumulation; very strongly
acid; clear wavy boundary. (6 to 15 inches thick)
Btssl--21 to 29 inches; light gray (10YR 7/2) clay, light brownish gray (10YR 6/2)
moist; moderate medium and coarse angular blocky structure; few wedge-shaped peds;
extremely hard, very firm; sticky and plastic; common fine, medium, and few coarse
roots; few fine pores; thin patchy clay films on surface of peds; common pressure faces;
few slickensides; few fine iron-manganese concretions; common medium and coarse
distinct yellowish red (5YR 5/6) and few fine distinct strong brown (7.5YR 5/6) masses
of iron accumulation; strongly acid; gradual wavy boundary.
Btss2--29 to 37 inches; grayish brown (10YR 5/2) clay loam, dark grayish brown (10YR
4/2) moist; moderate medium and coarse angular blocky structure; few wedge-shaped
peds; extremely hard, very firm; sticky and plastic; common fine and medium roots; few
fine pores; common medium pressure faces; few small slickensides; few fine iron~
manganese concretions; few medium faint dark yellowish brown (10YR 4/4) masses of
iron accumulation; moderately acid; clear wavy boundary. (combined thickness of Btss
horizons is 15 t 045 inches)
Btkl--37 to 53 inches; light brownish gray (10YR 6/2) clay loam, grayish brown (10YR
5/2) moist; moderate medium and coarse prismatic structure parting to moderate coarse
angular blocky; extremely hard, very firm; sticky and plastic; conunon fine and medium
roots; nearly continuous clay films along surfaces of prisms; few fine pressure faces; 7
percent coatings and masses of calcium carbonate along surfaces ofpeds; few fine streaks
of gypsum; few fine iron-manganese concretions; common fine distinct yellowish brown
(10YR 5/6) masses of iron accumulation; neutral; gradual wavy boundary. (0 to 20 inches
thick)
Btk2--53 to 75 inches; light gray (2.5Y 7/2) clay loam, light brownish gray (2.5Y 6/2)
moist; moderate medium and coarse prismatic structure parting to moderate coarse
angular blocky; extremely hard, very firm, sticky and plastic; common fine and medium
roots; few pressure faces; about 3 percent coatings and masses of calcium carbonate
along surfaces of peds; few fine streaks of gypsum; few vertical streaks of dark yellowish
brown soil materials; few fine iron-manganese concretions; common medium and coarse
distinct brownish yellow (10YR 6/8) and few fine distinct yellowish brown (10YR 5/6)
masses of iron accumulation; moderately alkaline; gradual wavy boundary. (0 to 26
inches thick)
B't--75 to 80 inches; distinctly and coarsely mottled light gray (2.5Y 7/2), brownish
yellow (10YR 6/8) and yellowish brown (10YR 5/4) clay loam; moderate medium and
coarse prismatic structure parting to moderate medium and coarse angular blocky;
extremely hard, very firm, sticky and platic; few fine roots; few small slickensides; few
coats of calcium carbonate on surfaces of some peds; few streaks of gypsum; few fine
and coarse siliceous pebbles; few fine iron-manganese concretions; slightly alkaline.
TYPE LOCATION: Navarro County, Texas; from the intersection of State Highway 22
and Farm Road 55 in Blooming Grove; 1.1 miles south on Farm Road 55; 3.8 miles west-
southwest 'on county road to flood prevention structure; 250 feet west of the west channel
below flood prevention structure; 100 feet north in post oak timber. Latitude 32 degrees,
02 minutes 33 seconds N, Longitude 96 degrees, 43 minutes 57 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness is more than 80 inches. The
boundary between the A and Bt horizons is abrupt over the subsoil crests and clear over
the subsoil troughs, and the texture change is abrupt. The solum contains 0 to 5 percent
siliceous pebbles, with some pedons containing up to 35 percent pebbles on and in the
surface layer. Depth to secondary carbonates ranges from 30 to 65 inches in most pedons.
The 10- to 40- inch particle size control section is clayey with average clay content
ranging from 35 to 50 percent. COLE ranges from 0.07 to 0.10 in the upper 20 inches of
the Bt horizon and the potential linear extensibility is greater than 2.5 inches in the upper
50 inches of the soil.
The A and E horizons average less than 10 inches thick in more than 50 pement of the
pedon, but they are as much as 15 inches thick over subsoil troughs. The A horizon has
hue of 10YR, value of 4 to 7, and chroma of 2 to 4. The E horizon has value I to 3 units
more than the A horizon. The A and E horizons are fine sandy loam, very fine sandy
loam, loam, or their gravelly counterparts. Reaction ranges from strongly acid to slightly
acid.
The upper part of the Bt horizon has hue of 2.5YR, 5YR or 7.5YR, value of 4 to 6, and
chroma of 3 to 8. Redoximorphic features in shades of red, brown or gray are in most
pedons or the matrix is mottled with these colors. Texture is clay loam or clay. Reaction
is very strongly acid or strongly acid, and the base saturation ranges from 50 to 75
percent.
The lower part of the argillic horizon is mottled in hue of 2.5YR to 10YR and are in
shades of red, brown, yellow, and gray. In some pedons, the lower Bt horizons have hue
of 2.5Y or 5Y. Texture is clay loam or clay. Reaction ranges from strongly acid to
slightly acid.
The Btk horizon, where present, has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of
2 to 6. Redoximorphic features are in shades of brown or yellow. Texture is clay loam or
clay. Reaction ranges from neutral to moderately alkaline. Visible carbonates range from
less than 2 to about 10 percent by volume and are in the form of concretions, masses and
coatings on the surface of peds.
The B't and BCk horizons, where present, have colors mainly in shades of gray or brown.
They are sandy clay loam, clay loam, or clay. Reaction ranges from moderately acid to
moderately alkaline and they are calcareous in some pedons. Calcium carbonate
concretions and gypsum crystals range from none to common.
COMPETING SERIES: These are the Bremond~ Crockett, Crosstell, Kurten, Navo,
Tabor and Zulch series. Similar soils are the Annona, Edge~ Gredge, Normangee, Payne,
Tabor, and Woodtell series. Bremond soils are moderately acid to neutral in the upper Bt
horizon and formed in alkaline clayey sediments. Crockett soils are moderately acid to
neutral in the upper Bt horizon, have base saturation of 75 to 100 percent, and formed in
alkaline marine clays and shales under prairie vegetation. Crosstell soils have solum
thickness of 40 to 60 inches and are underlain by weathered shale and sandstone of the
Cretaceous Woodbine formation. Kurten soils have solum thickness of 40 to 60 inches.
Navo, Normangee and Payne soils do not have an abrupt textural change between the A
and Bt horizon and in addition, Payne soils have COLE of less than 0.07. Tabor soils
have A horizons more than 10 inches thick in more than half the pedon and have matrix
colors in hue yellower than 7.5YR in the Btl horizon. Zulch soils have solum thickness
from 30 to 40 inches and are underlain by weathered shale of the Yegua formation. The
Annona and Woodtell soils are not dry in any part of the moisture control section for 90
cumulative days in most years. The Edge and Gredge soils do not have vertic properties,
have a significant decrease in clay within 35 inches of the surface and Edge soils are less
than 60 inches thick.
GEOGRAPHIC SETTING: Axtell soils are on broad, nearly level to strongly sloping
stream terraces and terrace remnants about 50 to 300 feet above the present streams. Also
included are terrace remnants on stream divides in erosional uplands. These sediments
are mainly of Pleistocene Age. Slopes are mainly between 0 and 5 percent, but range to
12 percent. The soil formed in clayey alluvium. The mean annual temperature ranges
from about 64 to 70 degrees F., and mean annual precipitation ranges from from 32 to 42
inches. Frost free days range from 240 to 270 days and elevation ranges from 200 to 600
feet. Thornthwaite P-E indices ranges from 54 to 66.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Crockett and
Tabor series and the Lufkin, Rader, and Wilson series. Crockett soils are on slightly
higher upland positions. Lufkin and Wilson soils are in similar or slightly lower terrace
positions and are dominated by colors with chroma 2 or less. Tabor soils are on positions
similar Axtell. Rader soils are on similar or slightly lower positions, and have fine-loamy
control sections.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very
slow. Runoff is low on slopes less than 1 percent, medium on 1 to 3 percent slopes, and
high on 3 to 5 percent slopes.
USE AND VEGETATION: Mostly cultivated in the past, but now in pasture. Some
areas are farmed to corn, grain sorghum, or small grains. Native vegetation is post oak,
blackjack oak, hickory, red cedar, greenbriar; grasses include mid and tall grasses such as
little bluestem, big bluestem, indiangrass, panicum and paspalum.
DISTRIBUTION AND EXTENT: Mainly in east-central Texas, but small areas are in
Oklahoma. This soil is of moderate extent.
Mitigation Plan for Modification of Tributary G1
USACE Project No.: 200400181
APPENDIX E
CORRESPONDENCE
WITH
TEXAS HISTORIC COMMISSION
Alan Plummer Associates, Inc.
D:\OFFICE\816\O2Ol\Tributary G1 Mit Plan new doc
T H E · C I T y O ~
February 2, 2004
Mr. Mark Denton
Director of State and Federal Review
Archeological Division
Texas Historical Commission
P.O. Box 12276
Austin, Texas 78711
RE: Bethel Road I
ST 99-05
1937 Culvert
FEB 04 2004
HISTORICAL COt,,tt,,l,l.~,.O.
Dear Mr. Denton:
The City of Coppell is designing construction plans for Bethel Road I. The project will
include channel improvements along 1900 linear feet of Stream Gl. We are in the
process of preparing an individual permit for review by the U.S. Army Corps of
Engineers. Design options for the channel are under evaluation, and the width and depth
of the channel have not been determined. We do know that the existing culvert under
Bethel Road will have to be replaced. The culvert was apparently constructed in ]937
and may have historic significance.
The project is located in the Grapevine Quadrangle and the limits of the project are
shown on the attached USGS map. Photographs of the culvert are enclosed. Please
review these photographs and let me know how we need to proceed with the design of the
channel improvements
Should you have any questions or need any additional information, please contact me at
972-304-7019. Your consideration of this matter is appreciated.
Sincerely,
Taylor
dinator
Enclosures
NO HISTORIC
PROPERTIES AFFECTED
PROJE~ MAY EROCEED
for F. kaweronce Oaks
State Historic PreseIvation Officer ~/
O ,e ......... .......