Stratford Manor-SY 980815WETLAND MITIGATION REPORT
STRATFORD MANOR DEVELOPMENT
U.S. Army Corps of Engineers
Project Number 1997-00423
Prepared for:
Brentwood Builders, Inc.
P.O. Box 702468
Dallas, TX 75370-5492
Prepared by:
Geo-Marine, Inc.
Environmental Engineering Services
550 East Fifteenth Street
Piano, Texas 75074
AUGUST 1998
Table of Contents
1.0 INTRODUCTION ..................................................................................................................................... 1
1.1 Background ...................................................................................................................................... 1
1.2 Site Description ............................................................................................................................... 1
1.2.1 Climate ............................................................................................................................. 1
! .2.2 Soils .................................................................................................................................. !
1.2.3 Plant Communities ........................................................................................................... 2
2.0 JURISDICTIONAL WATERS OF THE U.S .......................................................................................... 3
2.1 Methodology .................................................................................................................................... 3
2.2 Results .............................................................................................................................................. 5
3.0 AVOIDANCE, MINIMIZATION, AND UNAVOIDABLE IMPACTS ............................................... 6
4.0 MITIGATION PLAN ................................................................................................................................ 7
4.1 Description of Existing Wetlands ................................................................................................... 7
4.2 Description 0fWetland Mitigation Site .......................................................................................... 8
4.3 Wetland Site Comparisons .............................................................................................................. 9
4.4 Conceptual Mitigation Design ........................................................................................................ 9
4.4.1 Hydrology ....................................................................................................................... 10
4.4.2 Microtopography ............................................................................................................ 11
4.4.3 Vegetation ...................................................................................................................... 1 l
4.5 Monitoring and Success Criteria ................................................................................................... 12
5.0 PERTINENT NATURAL AND CULTURAL RESOURCES INFORMATION ................................ 13
6.0 LITERATURE CITED ............................................................................................................................ 14
APPENDIX A Figures .................................................................................................................... A-1
APPENDIX B Wetland Delineation Data Forms ............................................................................ B-1
APPENDIX C Threatened and Endangered Species Assessment ................................................... C-1
APPENDIX D Cultural Resources Site Assessment ...................................................................... D-1
List of Tables
1-1 Dallas County Average Climatic Conditions .......................................................................................... 1
2-1 Vegetation Present in the Northern Wetland ..................................................................................... 6
4-1 Species Composition of Herbaceous Vegetation to be Planted ....................................................... 12
111
1.0 INTRODUCTION
1.1 BACKGROUND
This report was developed to ensure compliance with state and federal laws regarding the
mitigation of impacts to waters of the United States (U.S.) during development of a 15-acre
residential development in the city of Coppell, Dallas County, Texas (Appendix A - Figures 1 and
2). Waters of the U.S. are subject to regulation by the U.S. Army Corps of Engineers (USACE) as
designated in Section 404 of the Clean Water Act (CWA). This report primarily serves as a
mitigation report, yet also provides: (1) a complete and accurate description of waters of the U.S.,
including wetlands, within the site; (2) a summary of avoidance and minimization measures, to be
taken where possible, and unavoidable impacts to the waters of the U.S.; and (3) a conceptual
.. mitigation plan designed to produce an on-site wetland that would result in a "net gain" of
functional wetland habitat.
1.2 SITE DESCRIPTION
1.2.1 CLIMATE
The average annual temperature of Dallas County is 66 degrees Fahrenheit (OF) (Table 1). Two
years in I0 will have a maximum temperature higher than 106OF in July and a minimum
temperature lower than 1 lOF in January (Coffee et al. 1980). The average growing season (nine
years in 10) will have 222 days with temperatures higher than 32OF. Precipitation occurs bimodally
- in the spring and fall months. Average annual precipitation is 35 inches with minimal snow in
January and December.
1.2.2 SOILS
Two soil units exist along the project site: Frio silty clay, occasionally flooded, and Trinity clay,
occasionally flooded. The following is a brief description of the soils (Coffee et al. 1980).
Table 1-1
Dallas County Average Climatic Conditions
Temperature (°F) Average
Months Average Average Min. Average Max. Precipitation (in.)
JAN 45.5 35.4 55.6 1.78
FEB 49.6 39.0 60.1 2.05
MAR 56.8 46.0 67.7 2.56
APR 66.4 56.0 76.7 4.81
MAY 74.0 64.1 83.9 4.16
JUN 81.7 71.9 91.4 3.01
JUL 86.0 76.2 95.8 1.94
AUG 85,5 75.3 95.7 2.14
SEP 78.2 68.1 88.2 3.77
OCT 67.9 57.2 78.5 3.88
NOV 55.8 45.4 66.0 2.69
DEC 48.3 38.3 58.3 2.27
YEARLY AVG. 66.3 56.1 76.5 35.06
Note: Ba.scd on 23 years of local records
Source: Coffee et al. 1980
· Frio silty clay is a well-drained, nearly level soil found in floodplains. This
soil is occasionally flooded and has slow permeability, slow runoff, and a low
erosion hazard. The surface layer is a moderately alkaline, dark grayish brown
silty clay. Between 7 and 32 inches, the soil is a moderately alkaline, very
dark grayish brown silty clay.
· Trinity clay soils are deep, poorly drained soils found on floodplains of the
Trinity River. The surface horizon is a dark gray clay approximately 7 inches
deep. Between 7 and 20 inches, the soil is a moderately alkaline, dark grayish
brown clay.
1.2.3 PLANT COMMUNITIES
The project site lies within the Blackland Prairie subregion of the central Texas natural region (U.S.
Fish and Wildlife Service [USFWS] 1979). The dominant plant species of undisturbed Blackland
Prairie is little bluestem (Schizachyrium scoparium), with common associated species that include
big bluestem (.4ndropogon gerardiO, switchgrass (Panicum virgatum), and sideoats grama
(Bouteloua curtipendula). In the cool season, annual forbs may appear dominant due to the low
composition of cool season grasses. While not truly dominant, these forbs are seasonally important
2
to wildlife (USFWS 1979). However, this classification is based on Kiichler's (1966) potential
natural vegetation classification system, which identifies natural climax vegetation communities as
they occurred prior to disturbance and may not accurately identify the vegetation occupying an area
at the present time. The land in this region has been converted to agricultural use and less than one
percent of the area is composed of natural climax vegetation communities COSFWS 1979). Within
the project site, little native vegetation communities were observed primarily due to historical
management and land use.
The plant communities currently present on the site are mixed woodlands and savannas. The
dominant woody species on the site include cedar elm, hackberry, osage orange, bur oak, bumelia,
pecan, American elm, green ash, and chinaberry. Herbaceous vegetation is sparse in the
woodlands, but the savanna communities include buffalograss, bermudagrass, Texas wintergrass,
tall aster, Japanese brome, rescuegrass, osarkgrass, violet ruellia, and nutgrass.
2.0 JURISDICTIONAL WATERS OF THE U.S.
2.1 METHODOLOGY
The Dallas County soil survey (Coffee et al. 1980) and a 1-foot contour interval topographic map of
the project site were studied to identify possible waters of the U.S. and areas prone to wetland
development. The project site was field checked, and the determination of waters of the U.S. was
performed on location in accordance with the Corps of Engineers Wetlands Delineation Manual
(Environmental Laboratory 1987). Field work was conducted on 20 May 1998 by Mr. Rudi
Reinecke, Wetland Ecologist, and Mr. David Pitts, Field Biologist, of Geo-Marine, Inc. (GMI).
Non-wetland waters of the U.S. include lakes, ponds, streams, ~c. Jurisdictional boundaries for
these water resources were defined in the field as the ordinary high water mark (OHWM). The
OHWM is the line on the bank established by the fluctuations of water and indicated by physical
characteristics such as a dear, natural line impressed on the bank, shelving, changes in the character
of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate
means.
Designation of an area as a wetland required positive field indicators of hydrophytie vegetation,
wetland hydrology, and hydrie soils. A routine wetland delineation data form (Appendix B) was
completed for each jurisdictional wetland type. If an area failed to contain positive indicators of all
three parameters, it was not designated as a potential jurisdictional wetland.
The fu'st parameter generally identified at each site was hydrophytic vegetation. The dominant
species in each vegetation layer were recorded at each potential wetland site. Plant species having
an indicator status of facultative (FAC), facultative wetland (FACW), or obligate wetland (OBL),
as listed in National List of Plant Species that Occur in Wetlands: 1988 National Summary (Reed
1988), are considered hydrophytic. Dominance was based on visual estimation of percent
coverage. Areas where hydrophytic plant species comprised greater than 50 percent coverage met
the hydrophytic vegetation parameter.
A site has wetland hydrology if water is present within the upper 12 inches of the soil for two
weeks or longer during the growing season. The determination of wetland hydrology for each
sampling point was based on positive indicators observed during the field investigation. Primary
indicators of wetland hydrology included inundation, saturation in the upper 12 inches, water
marks, drif~ lines, sediment deposits, or drainage patterns. Secondary indicators of hydrology
included oxidized root channels in the upper 12 inches, water-stained leaves, local survey data, and
the FAC-neutral test. At least one primary indicator or two secondary indicators of wetland
hydrology were required as evidence of wetland hydrology.
Soils were determined to be hydric if they met criteria set in the definition of a hydric soil: soils
that are flooded, ponded, or saturated long enough during the growing season to develop anaerobic
conditions in the upper part (National Technical Committee for Hydrie Soils 1991). An aquie
moisture regime develops under the anaerobic conditions of continuous soil inundation or
saturation for 17 to 29 days during the approximate 240-day growing season. Hydric soil
determinations were based on the presence or absence of hydric soil indicators. The presence of
indicators for hydric Soils was determined utilizing soil test pits dug within each potential wetland.
The condition of the soil was assessed for accumulation of organic material in the upper layer, Iow
chroma matrix color, mottling, or the development of an aquic moisture regime. One or more
positive indicators were required to classify the soil at each site as hydric. Soil sample colors were
correlated with Munsell® Soil Color Charts (1994) while in the field.
2.2 RESULTS
The majority of the site has historically been used for agricultural purposes, specifically livestock
grazing. Soils within the project site are mapped as Frio silty clay, occasionally flooded, and Trinity
clay, occasionally flooded. These soils are not listed in the National List of Hydric Soils. Field
surveys were conducted on two different dates - 20 May and 1 July 1998. From these surveys, two
jurisdictional wetlands within the 15-acre site were delineated. The two wetlands were 0.53 acre
and 1.795 acres in size which combined for a total of 2.325 acres.
The first jurisdictional wetland (Wetland A) was restricted to a 0.53-acre wooded area extending,
northeast from the westernmost site boundary (see Appendix A - Figure 3). This wetland appears
to have been a low swale that is now impounded from adjacent developments. The wetland had
positive indicators of all three wetland parameters (see Appendix B). Approximately 88.8 percent
of the vegetation was Faeultative, Faeultative Wet, and Obligate wetland vegetation. Hydrology
was a result of surface runoff within the project site, and positive indicators of hydrology were
present during the survey. The positive hydrie soil indicators were low chroma colors with
mottling.
The second jurisdictional wetland (Wetland B) was delineated during the later field survey (1 July
1998) by Presley Hatcher, Chief of Permits Section, and Mary Flores, Project Manager, with the
USACE, Fort Worth District, Regulatory Branch. This wetland, located north of Wetland A and
extending from the easternmost site boundary) fotal&i'i.795 ;;~:r~,s and included a large level area
with a series of small non-vegetated depressions (see Appendix A - Figure 3). The vegetation in
this area was dominated by the species listed in Table 2-1. Hydrology in this wetland consisted
of three indicators (i.e., water marks, sediment deposits, and water-stained leaves). Soils
consisted of two horizons: 0 to 4 inches was a mixed matrix of 60 percent 10YR 3/1 and 40
percent 10YR 4/6, and; the 4- to 10-inch horizon was a 10YR 4/6 sandy clay.
Table 2-1
Vegetation Present in the Northern Wetland
Dominant Plant Species Indicator Stratum Other Plant Species Present (<1%) Indicator Stratum
1. Ulrnus crassiflolia FAC T 1. Fraxinuspennsylvanica FACW- T
2. Celtis laevigata FAC T/S 2. Cephalanthus occidentalis OBL S
3. Asterpraealtus FACW H 3. Elymus canadensis FAC+ H
4. Opuntia sp. H
5. Stipa leucotricha H
6. Ruellia nudiflora UPL H
7. Bromus unioloides H
8. Bromus japonicus FA(2U H
9. Limnodea arkansana H
10. Cyperus rotundus FAC H
H = Herbaceous
S = Shrub
T = Tree
.Presley Hatcher indicated that hydrology was the primary parameter of the wetland delineation
for this site. He also explained that the vegetation had been altered primarily due to the
extensive agricultural history (i.e., grazing and mowing practices); therefore, the vegetation was
not a good parameter of wetland status on this site. He further indicated that the soils met the
hydric criteria due to two factors - being Trinity clays and their position within the landscape.
3.0 AVOIDANCE, MINIMIZATION, AND UNAVOIDABLE IIVIPACTS
The purpose of the Stratford Manor Development is to construct a residential development and
an adjacent park. The residential development will occupy the majority of the southern portion
of the 15-acre site. The park will be located on the northern section between the residentiak
development and Denton Creek (see Appendix A - Figure 4), The residential development will
provide 29 single family housing units. The proposed park is part of a master plan to develop a
green belt adjacent to Denton Creek. This park will be contiguous to the existing park On the
east and the proposed park on the west. The only improvements to this park will be a nature trail
on the northern boundary of the property which will connect to the existing trail on the eastern
park.
Through the process of designing the residential development, several plans were considered in
order to minimize the impacts to the natural resources. Due to the orientation of the wetlands,
developing the site to completely avoid the wetlands would not be feasible. Minimization of the
impacts to the wetlands was the next approach. The original development consisted of 31 single
family units with large lots. To avoid impacting a portion of Wetland B, two lots were
abandoned and the remaining lots were reduced in size. The second minimization was achieved
by decreasing the depth of the lots to aeeomodate two green belts, oriented north-south, adjacent
to the eastern and western property lines (see Appendix A o Figure 4). Through these
minimization tactics, a total of 0.855 acre of wetlands was avoided. The current development
plan would impact 1.47 acres of wetlands through the development of 12 acres for 29 single
family units.
The next in the process includes compensating or mitigating for the 1.47 acres of wetlands that
will be unavoidably impacted. The following conceptual mitigation plan will create additional
.. wetlands .to compensate for the wetland functions and values lost by the construction of the
residential development, in addition to enhancing 0.5 acre of the existing wetlands, so-that
negative impacts will not occur to local hydrology, upstream and downstream aquatic resources,
and wildlife habitat. The 1.47 acres of created compensatory wetlands and the 0.5-acre wetland/
enhancement area ..will be deed restricted to the home owners association so that the wetland
mitigation project will remain in perpetuity.
4.0 MITIGATION PLAN
To develop an appropriate compensatory mitigation plan, the existing wetland functions and
values need to be addressed so that they can be incorporated into the proposed plan. Secondly,
the plan needs to address the location of the mitigation site and characterization of the land use
history, dominant vegetation, local hydrology, and soils. Then, a conceptual mitigation plan is
developed using this'information. This mitigation plan addresses how the proposed wetlands are
appropriate compensation for adverse impacts to the existing wetland functions and values.
Finally, a monitoring plan is developed so that the mitigation plan will continue to be a success
without future maintenance.
4.1 DESCRIPTION OF EXISTING WETLANDS
The existing wetlands were a result of recent development within the surrounding area. Both the
properties to the east and west have been filled in for development purposes. Due to the adjacent
7
landfilling practices of the past five years, the precipitation that falls onto the site settles to the
low areas, Wetlands A and B, and does not leave the site except under heavy precipitation
events. The limited surface flow drainage, coupled with the low permeability of the clay soils,
permits the existing, wetlands to be saturated for approximately two to three months during
average years. Retaining the hydrology on-site is one of the dominant functions of the wetlands.
This water storage capacity reduces or prevents downstream flooding during heavy precipitation
events.
The vegetation within the existing wetland sites is primarily a function of the land use history.
The entire 15-acre site has been grazed by livestock for more than 50 years. Recently, the site
has been overgrazed by horses which was indicated by the poor species composition, high
browse line, and the high stocking rate present during the surveys. Wetland A was located in the
lowest point of the pasture, thereby being saturated for a longer duration than Wetland B. Due to
the longer saturation period, Wetland A has a more favorable water balance which has created a
more hydric wooded vegetation community, particularly shrubs (see Appendix B). Water levels
fluctuate more ellen in Wetland B, and the vegetation consists of a more open savanna
community (see Table 2-1). The woody component of both wetlands provides an additional
function for wildlife habitat.
The structural composition of the vegetation provides a unique value to the wetlands on this site.
Although the site has been grazed heavily in the past, trees have escaped browsing and have
grown to significant stature. These trees range in size from 4 to 16 inches diameter breast height
(DBH). The tree-age gradient provides greater value to the wildlife habitat function. However,
the tree species are of lower successional value and only provide a low quality food source for
wildlife.
4.2 DESCRIPTION OF WETLAND MITIGATION SITE
The proposed wetland mitigation area (see Appendix A - Figure 4) is very similar to the existing
wetland sites in land use history, vegetation, soils, and hydrology. The land use history, since it
is on the same property and was not cross-fenced, is identical. As mentioned earlier, the entire
15-acre site has been historically heavily grazed by livestock and more recently by horses. This
8
historical land use has had the largest effect on vegetation structure and composition within the
mitigation site. Approximately 50 trees were located on the mitigation site. Trees varied in size
from 4 inches to 32 inches in DBH, with a species composition of bur oak, bumelia, cedar elm,
pecan, American elm, hackberry, osage orange, green ash, and chinaberry. The soils are
identical between the proposed wetland site and the existing wetlands. The source of hydrology
for the proposed wetland mitigation site will be the same as the existing wetlands; hydrology is
supplied from surface runoff from the southern portion of the property.
4.3 WETLAND SITE COMPARISONS
The functions and values of the existing wetlands are primarily site specific as they relate to
location of the compensatory mitigation. Therefore, the proposed wetland mitigation site should
be within the same watershed if mitigation on site is not feasible. To replace the two primary
functions of the existing wetlands, flood storage and wildlife habitat, the location nearest to the
riparian corridor would be the most suitable. The adjacent proposed park is an ideal place for the
mitigation. Mitigation adjacent to a riparian corridor would allow surface flow to filter out
sediments, nutrients, and chemicals prior to discharge into a flowing waterbody (i.e., Denton
Creek). Increased wildlife utilization will occur in larger habitat patches, especially those
adjacent 'to a larger riparian corridor. The proposed wetland mitigation area has several species
of trees that are of substantial stature. These trees vary from 4 inches to 32 inches DBH. The
additional species composition and age stratification of the mitigation area, coupled with other
conceptual wetland parameters, would substantially enhance the wildlife habitat value.
4.4 CONCEPTUAL MITIGATION DESIGN
To develop an appropriate mitigation design for the unavoidable wetland impacts, the functions
and values of the existing wetlands need to be replaced. As described in Section 4.3, the
proposed site offers the majority of the structural components that assist in replacing the
functions and values lost. As indicated in Section 3.0, 0.5 acre of existing wetlands would be
enhanced in addition to 1.47 acres of compensatory wetland creation. The wetland enhancement
area is located adjacent to the wetland creation area; therefore, this mitigation design addresses
the enhancement and creation as the same project. The conceptual mitigation design is
9
comprised of three components - hydrology, microtopography, and vegetation (see Appendix A -
Figure $).
4.4.1 HYDROLOGY
Wetland hydrology is the single-most important component to a successful wetland mitigation
project. Several design strnetures need to be in place to develop a sufficient source of hydrology
on the mitigation site. The first is to get the water on site, second is to retain the water, and third
is to expel the overflow water from the site under heavy precipitation events.
The primary source of hydrology for the proposed wetland, like the existing wetlands, is surface
flow from the southern portion of the site. However, the proposed wetland would receive
surface flow from the new residential lots via the streets. The runoffthen would be focused into
a concrete flume with velocity attenuators as it enters the wetland site. To minimize erosion, 4-
to 8- inch stones for riprap will be placed around the flume; no cement will be used to grout the
stones in place. Over time a natural landscape will be created through vegetation growth among
the riprap structure.
Retaining the hydrology on site is not a difficult issue since the existing soils have very slow
permeability. However, once the water is on site, some structures would need to be in place to
prevent flooding adjacent properties. Therefore, earthen dikes would be constructed on the
eastern and western property boundaries. The soil materials would be retained from the site to
avoid introducing any new vegetative seed sources. The earthen dikes would be constructed to
retain a depth of no greater than 12 inches of water on site. To accomplish this, the dikes will
taper as they go uphill toward the north. Earthen dikes would not be necessary on the northern
and southern boundaries of the mitigation areas. The highest edge of the Denton Creek bank
would act as the northern perimeter of the wetland. The fill for the residential development
would be the southern boundary of the wetland.
The proposed wetland outflow structure has two primary purposes - to control the water level
within the wetland and to prevent water eroding or scouring the wetland. To accomplish these
tasks, a wetland outflow structure will be designed away from the perimeter of the wetland. This
10
outflow structure would consist of a 4.5-foot square drain with a 48-inch by 4-inch horizontal
opening on all sides (see Appendix A - Figure 6). The elevation of the drain structure is
important to control the hydrology elevation. The bottom of the drain will be approximately 6
inches below the top of the Denton Creek bank (northern boundary). Once detailed hydraulic
designs have been' completed, the exact number of wetland drain structures will be determined to
prevent water overflowing the top of the creek bank causing scouring. If multiple wetland
outflow structures are necessary, they will be placed equidistant apart along the proposed
stormwater drainage. The wetland outflow structures will be constructed of concrete with closed
tops to prevent harm to wildlife.
4.4.2 MICROTOPOGRAPHY
The microtopography will be enhanced to improve the wildlife habitat and flood control function
of the proposed wetland. Microtopography would be created by excavating a series of shallow
depressions. Two important concepts need to be addressed in the construction of these
depressions. The first is to avoid the the root systems of large trees, to prevent tree mortality.
The second is to avoid the existing wetlands which will be a seed source. Top soil from these
excavations would be stockpiled and replaced after 6 inches of sub-soil is removed. This would
ensure important nutrients and seed sources present on the site. In addition to creating higher
quality wildlife habitat and flood storage, the microtopography would offer greater vegetation
habitat for increased species diversity.
4.4.3 VEGETATION
The vegetation component of this wetland mitigation plan is one of the most important when
considering the wildlife habitat functions and values to be replaced. The wetland mitigation site
contains a greater variety of tree species and structural composition than the area to be impacted.
However, additional hydric shrubs such as swamp privit (Foresteria acurninata) and buttonbush
(Cephalanthus occidentalis) plugs will be planted at a density of 35 shrubs per acre of each
species. The herbaceous vegetation will be planted using a combination of rhizome and seed
spreading depending upon availability. Approximately 15 pounds of pure live seed of the
herbaceous seed mix should be planted. The preferred species will grow well in low light
I1
conditions, heavy clays, variable water depths, and are local to the north-central Texas area
(Table 4-1). However, a modified species composition may be necessary depending upon the
availability at the time of planting. Planting will not occur until the spring, after all earthmoving
activities are completed.
Table 4-1
Species Composition of Herbaceous Vegetation to be Planted
Species Composition
Paspalum spp. Oeloridanum, plicatulum, setaceurn) 5%
Panicum spp. (virgaturn, dichotomiflorurn) 10%
Setaria spp. (geniculata) 5%
,- Carex spp. ( tribuloides, amphibola, crus-corvi) 15%
Cyperus spp. ( esculentes) 15%
Eleocharis spp. (parvula, microcarpa) 10% ·
Juncus spp. (torreyi, effusus) 15%
Eryngium spp. (hookeri, leavenworthit~ 5%
Sagittaria spp. (latifolia) 20%
Total 100%
Planting trees is not being considered as a part of the mitigation plan due to the abundance of
existing mature trees (greater than 50 trees) in the mitigation site. Numerous trees will rapidly
sprout within the site following the cessation of the heavy grazing that currently exists on the
property.
4.5 MONITORING AND SUCCESS CRITERIA
During the development of the proposed wetland mitigation project, all components need to be
monitored to ensure success of the mitigation site. Secondly, a monitoring plan will also
determine when the wetland is functioning without any further human intervention. The site
should be monitored by qualified biologists for the success of vegetation establishment on an
annual basis for at least five years until the success criteria are met. However, during the two
years after the wetland is planted, the site should be monitored during the dry seasons to
determine the need for irrigation. Irrigation to this site should be performed, as necessary,
during these dry seasons. Detailed annual monitoring reports will be submitted to the USACE
summarizing the events of the mitigation project (i.e., additional planting, grading), mortality of
the vegetation, and proposed future events on the mitigation site (i.e., additional planting). To
12
determine vegetation mortality and whether the success criteria have been met, one permanent
10 meter (m) by 100 m belt transect will be oriented within the wetland. This belt transect will
be used to monitor the survival of the shrubs planted. The two ends of the I00 m belt transect
will be used to establish 1-m point intercept transects to monitor the herbaceous species
composition and cover within the wetland.
The wetland success criteria includes: the wetland must be saturated seasonally at a minimum 5
percent of the year (this may be monitored by presence of hydric indicators and presence of
hydric vegetation), the vegetation present must be greater than 50 percent hydrophytic (i.e., FAC,
FAC+, FACW, OBL), and shrub survival must be greater than 70 percent. Once these criteria
are met, a wetland delineation will be conducted by a qualified wetland biologist and submitted
to the USACE for its records of completion.
5.0 PERTINENT NATURAL AND CULTURAL RESOURCES INFORMATION
In compliance with the Nationwide Permit 26, Notification General Conditions, a threatened and
endangered species survey (Appendix C) and a cultural resources survey (Appendix D) were
conducted on the site to identify potential impacts. These surveys and subsequent reports were
conducted to inform the U.S. Fish and Wildlife Service and State Historic Preservation Officer
of potential impacts to the respective resources.
13
6.0 LITERATURE CITED
Coffee, D.R., R.H. Hill, and D.D. Ressel. 1980. Soil Survey of Dallas County, Texas. U.S.
Department of Agriculture, Soil Conservation Service, in cooperation with Texas
Agricultural Experiment Station.
Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical
Report Y-87-1, U.S. Army Waterways Experiment Station. 100 p.
Kiichler, A.W. 1966. Potential Natural Vegetation of the Conterminous United States. American
Geographical Society, New York. Map.
National Technical Committee for Hydric Soils (NTCHS). 1991. HydHc Soils of the United
States. Miscellaneous Publication 1491. USDA. Soil Conservation Service.
McMahan, C.A., R.G. Frye, and K.L. Brown. 1984. The Vegetation Types of Texas Including
Cropland. Texas Parks and Wildlife Department, Wildlife Division, Austin. 40 p.
Reed, P.B., Jr. 1988. National List of Plant Species that Occur in Wetlands: National Summary.
Modified 1996. U.S. Fish and Wildlife Service. Biol. Rep. 88(24). 244 p.
U.S. Fish and Wildlife Service (USFWS). 1979. Unique Wildlife Ecosystems of Texas. U.S.
Fish and Wildlife Service, Department of the Interior, Region Two. 164 p.
14
APPENDIX A
Figures
'Project Ar~a
! -
DALLAS COUNt[
FORT ~ / z~.c -
_wo_~- ~' _ -~.-~ c~ ~l
_ . _ ~~ ; / (Not to S~e)
Fig~e 1. General project ~cn map.
..'~:.,~
. .. '--~/~ ~ /
~ ~',,
LO~
~ w~~ oo~
Fig~e 2. Specific rasp of~e project site. (~grce: YxDOT cog,~ files)
~ ~ Legend
"'"'-.. *'~ ~"'I z/xxz" Project boundaries
~' '" -- - - / I
Foot
intervals
contour
I
I
~'~ 1 Foot contour intervals
~ Wetland~
!
-.
? .%
t'''~ : Wetland B
!
!
I
!
I
Wetland A 1~
I I
I
I
I
I
I
!
I
I
I
I
I
N
100 0 200 Feet
Deforest Road SCALE
Figure 3. Jurisdictional waters of the U.S., including wetlands within the project site.
Wetland Creation and
Storm Sewer D, rain ~/ ~ Enhancement Area
~: ...... , ~,.'i~),,~ .~/~.,
:"~'~' ""' ";.,'~:.: :-' : f'-.:.'?:i:
[ ! ":. ~ !, ?; Avoided Wetland
I i~..
'i
I
Avoided Wetland
"
I
Figure 4. Lq.cation of avoided wetlands, wetland mitigation site, and proposed residential plat orientation.
Legend
~ Denton Creek Bank ~ Potential Hike and Bike Trail Alignment/
~ Created/Enhanced Wetland ~ Wetland Outflow Structure /'?/'~',
~ Earthen Dike \ j j.,:
Shallow Depression
North ~ ,,{
Tree
{~ Shrub
... . ..,.,~.
· '
t,,/
-' I/ ~ ~ - '" . ~.-" ~':' :~:~
[/ /// / ~ Denton Creek
!i/i //, // , ',,,~ ,,,,/, '~.j~ ~.~
-t l' : ~ Lit i
~.."/ ~'~-~...L / . i ~ · ~1~ ~ ',\ A.~.Z~'~, n, ~,l,' x.~-
~~'~' ~'~'-----.-~'." IX,, i\ ~ \\ ~ ,'
,./.....' ~ //./ . ,x . ..
~'.~ ~~, / ,,,
i .: ~.~ ~
~ ,'t- '"'~ i~' , ' ~-~___~ ",.-~-" ~ ..... ..'"~./ ...-' ~'"~
-"',~ ' - ' 4 ~L--' ~',,. i ~ ~ .(. / .%r- r
I,,.~ ., , ,, ~ ~dl ,.,=.'-~ i ~ t ~x." ~.' ~/-.._ /'
.,~,..~ ~ ~i.~.~lt, ~ 'y.------ ~ .-. ~ ..~", /' / ,. ~, ,
'1 "~.~ ~
I ~ , ....~ ~. · .' t ~ :
q, .:,/z...~ '¢-' , ,i --.I ~,~ ...,. ~'"' , "... .-' .... .,.t.i ~, .. ,,t.~l~-. -~. ~,~'' l.. ~ 1.
~ _-~-""~ ,,' ~ ',' --L>~' '~ '-, ~['-'t !
% .,,. ., "~'g~., ',~./h'---~ ~[ ' ,, ",". ~.~ '. '-':'- ~
. ,,
x.,.: ~ ,~
\
Residence
Residence
Concrete Flume
Figure 5. Conceptual mitigation plan.
Wetland Overflow Drain (4 - 48 X 8 inch Openings)
~'. ~~_~ ~'~tr.. ~, - ' -, ~' ,~ ' ~{~~2 ~,,~w _ Top of E~en,,~ RI/ ,~- Dike / Creek Br ~] -
,'r ' ' Top Water Level
To Horizontal Sto~ Sewer Drain
V
4 - 8 inch Rock Riprap
Concrete Flume
Cul-de-Sac
Figure 6. Typiqal section of wetland outflow structure and schematic of concrete flume structure.
APPENDIX B
Wetland Delineation Data Forms
ROUTINE WETLAND DETERMINATION DATA FORM
Project Site: Stratford Manor Residential Development Date: 20 May 1998
Applicant/Owner. Brentwood Buildem, Inc. County: Collin
Investigator. Rudi Reinecke, David Pitts State: Texas
Do Normal Circumstances exist on the site? v' Yes ~ No Community ID: Forested wetland
Is the site significantly disturbed (Atypical Situation)? ~ Yes v' No Transect ID:
Is the area a potential Problem Area? yes v' No Plot ID: Wetlands
(If needed, explain on reverse.)
VEGETATION
Dominant Plant Species Indicator Stratum Dominant Plant Species Indicator Stratum
1. Celtis laevigata FAC 9. Aster l~reealtus FACW- H
2. Maclure pomifere FACU T 10.
3. Smilax bona-nox FAC S 11.
4. Ulmus crassifolia FAC T 12.
5. Ulmus americana FAC T 13.
6. Fraxinus pennsylvanica FACW T 14.
7. Foresteria accuminata OBL S 15.
8. Cephalanthus occiclentalis OBL S 16.
Percent of Dominant Species that are OBL, FACW, or FAC (excluding FAC-): 8/9 = 88.8%
Remarks: Area is in mowed pasture.
'-' HYDROLOGY
Recorded Data Available (Describe in Remarks): Wetland Hydrology Indicators:
Aerial Photographs Pdmary Indicators:
Other v' Inundated
,,' No Recorded Data Available ~ Saturated in Upper 12 inches
v' Water Marks
Field Observations: ~ Drift Lines
Depth of Surface Water <=12 (in.) ~ Sediment Deposits
Depth to Free Water in Pit: (in.) ~ Drainage Patterns in Wetlands
Depth to Saturated Soil: (in.) Secondary Indicators (2 or more required):
v' Oxidized Root Channels in Upper 12 inches
Remarks: v' Water-Stained Leaves
Local Soil Survey Data
FAC-Neutral Test
~ Other (Explain in Remarks)
SOILS
Map Unit Name: Sedes & Phase: Drainage Class:
Taxonomy Subgroup: Field Observations Confirm Map Type? Yes No
Profile Description:
Depth (in.) Hodzon Matrix Color MotfJe Colors Mottle Abundance/Contrast Texture, Concretions, Structure, etc.
0-3 10 YR 3/1 5 YR 5/8 7% Clay
3-12 Mixed 10YR411 & 10YR4/3 10YR6/2 2% Clay
Hydric Soil Indicators:
Histosol v' Low-Chroma Colors
Hlstic Epipedon Concretions
Sulfidic Odor High Organic Content in Surface Layer in Sandy Soils
Aquic Moisture Regime Organic Streaking in Sandy Soils
Reducing Conditions Listed on Local Hydric Soils List
Gleyed Listed on National Hydric Soils List
Other (Explain in Remarks)
Remarks:
VVETLAND DETERMINATION
Hydrophytic Vegetation Present? v' Yes No
Wetland Hydrology Present? ,,' Yes ~ No Is this Sampling Point within a Wetland? ,,' Yes No
Hydric Soils Present? v' Yes ~ No
Remarks:
,, Signature
APPENDIX C
Threatened and Endangered Species Assessment
THREATENED AND ENDANGERED SPECIES ASSESSMENT
STRATFORD MANOR DEVELOPMENT
Prepared for:
Brentwood Builders, Inc.
P.O. Box 702468
Dallas, TX 75370-5492
Prepared by:
O Geo-Marine, Inc.
Environmental Engineering Services
550 East Fifteenth Street
Plano, Texas 75074
AUGUST 1998
TABLE OF CONTENTS
INTRODUCTION ................................................................................................................................. 1
THREATENED/ENDANGERED SPECIES ....................................................................................... 4
FEDERAL...: ............................................................................................................................. 4
STATE ........................... : ........................................................................................................... 5
RESULTS ................................................................................................................................. 8
SENSITIVE NATURAL COMMUNITIES ......................................................................................... 9
CONCLUSIONS ................................................................................................................................... 9
LITERATURE CITED ....................................................................................................................... 10
ATTACHMENT A Dallas County Species Lists
LIST OF FIGURES
Figure Page
1 General location map of the project area .................................................................................. 2
2 Specific map of the project site ................................................................................................. 3
LIST OF TABLES
Table Page
1 Habitat Requirements and Reasons for Decline of Federal/State Listed
Endangered and Threatened Species Potentially Occurring in Dallas County .................... 6
INTRODUCTION
A 15-acre parcel of land, located within the City of Coppell, Texas, is proposed for residential and
recreational development by Brentwood Builders, Inc. The project site is located in northwest
Dallas County, within Mesquite's southern city limits (Figures 1 and 2). The site is a long, narrow
rectangle in a north-south orientation. The northern boundary is Denton Creek, and the southern
boundary is DeForest Road.
The average annual temperature of Dallas County is 66 degrees Fahrenheit (°F) (Coffee et al. 1980).
The average growing season is 222 days (i.e., above 32°F). Precipitation occurs bimodally, in the
spring and fall months. Average annual p.recipitation is 35 inches with minimal snow in January
and December.
The project site lies within the Blackland Prairie subregion of the central Texas natural region CLI.S.
Fish and Wildlife Service [USFWS] 1979). This classification is based on natural climax
vegetation communities as they occurred prior to disturbance. The dominant plant species of
undisturbed Blackland Prairie is little bluestem (Schizachyrium scoparium), with common
associated species that include big bluestem (Andropogon gerardiO, switchgrass (Panicurn
virgaturn), and sideoats grama (Bouteloua curtipendula). Annual forbs, which are seasonally
important to wildlife, may appear dominant during the cool season. The land in this region has
been converted to agricultural use and less than one percent is composed of natural climax
vegetation COSFWS 1979). Within the project site, few native vegetation communities were
observed, primarily due to past management and land use.
McMahan et al. (1984) conducted more recent and site-specific vegetation mapping of Texas.
According to this classification system, the predominant vegetation types within the project site are
water oak-elm-hackberry forest (i.e., bottomland hardwood) in the floodplain and agriculture crops
in the upland areas.
Project Area
~ ......
DALLAS
DALLAS
~OVE
I
Figure 1. General project area map.
:,-.
0 ~
P~L~S ~E
.. ~ f ~ ~HD~ ~ tP~
~ G~CE J LO~
~ ~ o
Figaro 2. Specific map of~e project site. (~u~: T~OT coun~ files}
The plant communities currently present on the site are mixed woodlands and savannas. The
dominant woody species on the site include cedar elm, haekberry, osage orange, bur oak, bumelia,
pecan, American elm, green ash, and chinaberry. Herbaceous vegetation was sparse in the
woodlands, but the savanna communities included buffalograss, bermudagrass, Texas
wintergrass, tall aster, Japanese brome, rescuegrass, osarkgrass, violet ruellia, and nutgrass.
THREATENED/ENDANGERED SPECIES
FEDERAL
The Endangered Species Act (ESA) of 1973 (P.L. 93-205) and the amendments of 1988 (P.L.
100-578) were enacted to provide a program of preservation for endangered and threatened
species and to provide protection for ecosystems upon which these species depend for their
survival. The ESA requires all federal agencies to implement protection programs for designated
species and to use their authorities to further the purposes of the Act. Responsibility for the
'listing of an endangered or threatened species and for the development of recovery plans lies
with the Secretary of Interior and Secretary of Commerce. The U.S. Fish and Wildlife Service
(USFWS) is responsible for implementing the ESA within the continental United States.
.An endangered species is a species which is in danger of extinction throughout all or a significant
-portion of its range. A threatened species is a species likely to become endangered within the
foreseeable future throughout all or a significant portion of its range. Proposed species are those
which have been formally submitted to Congress for official listing as endangered or threatened.
In addition, the USFWS has identified species which are candidates for possible addition to the
list of Endangered and Threatened Wildlife and Plants (50 CFR Parts 17.11 and 17.12) under the
ESA of 1973, as amended. The USFWS maintains a candidate list to: (1) provide advance
.. knowledge of potential listings that could affect land planning decisions, (2) solicit input to
identify candidates not requiring protection or additional species that may require protection
4
. under the ESA, and (3) solicit information needed to prioritize the order in which species will be
proposed for listing. Candidate species have no legal protection under the ESA.
Only two federally listed endangered species occur or potentially occur within Dallas County
(Attachment A). Information pertaining to the distribution, habitat requiremems, and reason for
decline of these species is listed in Table 1.
Critical habitat is def'med in Section 3 of the ESA as: (1) the specific areas within the
geographical area occupied by a species, at the time it is listed in accordance with the Act, on
which are found those physical or biological features (i) essential to the conservation of the
species and (ii) that may require special management considerations or protection; and (2)
specific areas outside the geographical area occupied by a species at the time it is listed, upon a
determination that such areas are essential for the conservation of the species. "Conservation"
means the use of all methods and procedures needed to bring the species to the point at which
listing under the Act is no longer necessary. Section 4(a)(3) of the Act, as amended, and
implementing regulations (50 CFR Part 424.12) require that, to the maximum extent prudent and
determinable, the Secretary will designate critical habitat at the time a species is determined to be
endangered or threatened. No designated critical habitat was observed within the project site.
STATE
The Texas Parks and Wildlife Department (TPWD), Natural Heritage Program, maintains
computerized records of state-listed threatened and endangered species by county. The State of
Texas does not list threatened and endangered species using the same criteria as the federal
government. When the USFWS lists a plant species, the State of Texas then lists that plant.
Thus, the list of threatened and endangered plants in Texas is the same as the federal list.
Table 1
Habitat Requirements and Reasons for Decline of Federal/State Listed
Endangered and Threatened Species Potentially Occurring in Dallas County
Status Habitat Present In
Common/Scientiric Name Fed. St. Habitat Requirements/Reasons for Decline Project Site
Texas homed lizard T Arid to semi-arid land with sparse vegetation and sandy to rocky No
Phrynosoma comutum soils/pesticides, commercial exploitation
Timber rattlesnake T Dense thickets, open upland woods, second-growth abandoned YES
Crotalus horridus agriculture rields/???
BIRDS
American peregrine falcon T E Rio Grande floodplain and terrace/pesticides, collecting by falconers No
Falco peregrinus anatum
Arctic peregrine falcon T T Rio Grande floodplain and terrace/pesticides, collecting by falconers No
Falco peregrinus tundrius
Black-capped vireo E E Broad-leaved shrublands/habitat destr~tion and modification, No
Vireo atticapillus cowbird brood parasitism
Brown pelican E E Along the Atlantic and Gulf of Mexico coasts, rare inland/pesticides No
Pelecanus occidentalis (DDT)
Golden-cheeked warbler E E Mature juniper woodland/loss of habitat, cowbird nest parasitism No
Dendroica chrysoparia
Interior leasttem E E Inland river sandbars for nesting and shallow water for No
Sterna antiserum thalamus foraging/declining population, riverine alterations
Reddish egret T Shallow open salt pans/??? No
Egretta rufescens
White-faced ibis - T Marshy areas and lakes/pesticides No
Plegadis chihi
Status Habitat Present In
Common/Scientific Name' Fed. St. Habitat Requirements/Reasons For Decline Project Site
Wood stork - T Lakes, ponds, and rivers/habitat loss, altered hydrology YES
Mycteria americana
White-tailed hawk - T Open coastal grasslands and semi-arid inland brush/??? No
Buteo albicaudatus
Whooping crane E E Winters on salt fiats, freshwater marshes, barrier islands/habitat loss No
Grus americana
Red wolf E E Heavily vegetated areas, coastal prairie and marsh/habitat loss, No
Can/s rufus hybridization
Fed = Federal E = Endangered
St. = State T = Threatened
Source: Erlich et. al. 1988; National Geographic Society 1987; Stebbim 1985; Tennant 1985; Texas Parks and Wildlife Departmem (TPWD) 1997; USFWS
1998; World Wildlife Fund 1990, 1992, 1994
The state has separate laws governing the listing of animal species as threatened or endangered.
Threatened and endangered animal species in Texas are those species so designated according to
Chapters 67 and 68 of the Texas Parks and Wildlife Code and Section 65.171 - 65.184 of Title
31 of the Texas Administrative Code. Animals that are not currently listed by the federal
government may be listed as threatened or endangered. The state does not have the authority at
this time to list invertebrates. The state lists seven endangered species and seven threatened
species as occurring or potentially occurring in Dallas County (see Attachment A and Table 1).
RESULTS
On 20 May 1998, two biologists visited the project site to conduct sury. eys for wetlands and
federal or state-liSted endangered/threatened species and their habitat. No federal or state-listed
endangered/threatened species were observed within the project site. Suitable habitat was not
observed within or adjacent to the proposed project site for federally listed
endangered/threatened species (see Table 1).
Suitable habitat exists for the timber rattlesnake, a state-listed threatened species. The hardwood
community in the middle of the property had been continuously inundated for the three months
previous to the site visit, and timber rattlesnakes were not observed. Small areas of suitable
upland habitat (i.e., upland woods) also exist. However, the majority of the upland areas have
been cleared of woody vegetation, and the small, isolated nature of the remaining pockets of
upland thickets would significantly decrease the potential for timber rattlesnakes to occur on the
upland areas. Therefore, there is moderate potential for the timber rattlesnake to occur on the
project site.
The wood stork is a state-listed threatened species and a rare to casual post-nuptial visitor along
the Trinity River watershed. Numerous sightings have been reported for Dallas County (Pulich
1998). Although approximately 300 feet of suitable habitat exists on the northern boundary of
the property along Denton Creek, both upstream and downstream has been cleared for
development. Wood storks were not observed during the surveys, but they do have a moderate to
Iow probability of occurrence along the Denton Creek corridor on the project site.
SENSITIVE NATURAL COMMUNITiES
Three natural communities (Sugarberry-Elm series, Little Bluestem-Indiangrass series, and
Pecan-Sugarberry series) are listed by the TPWD as potentially occurring in Dallas County. The
Sugarberry-Elm series is a broadly defined deciduous forest occurring on floodplains and mesic
slopes primarily in central and south Texas. The Little Bluestem-Indiangrass series is a broadly
... defined upland tallgrass prairie that historically occurred throughout north-central Texas, but is
now restricted to small and isolated relicts. The Pecan-Sugarberry seres is a deciduous forest or
woodland occurring along riverine floodplains with heavy textured and calcareous soils. Field
observations confirmed the presence of the Sugarberry-Elm series as the predominant vegetation
series with in the bottomland hardwood communities on the project site.
CONCLUSIONS
Fourteen state- or federally listed endangered or threatened species are listed as potentially
occurring in Dallas County. No federal or state-listed species were observed on the project site.
Suitable habitat exists for the timber rattlesnake and wood stork, both state-listed threatened
species. Development of the proposed project would preclude these species from the project site.
The timber rattlesnake, if present, would not be significantly impacted by the proposed
development. Few individual timber rattlesnakes would be present (if at all) on the project site,
and development of the site would not significantly affect the species. The wood stork is a
migratory species and, if present, would only use habitat on the project site for brief periods.
Wood storks do not breed in Dallas County. Therefore, this bird species would not be
significantly affected by the proposed development.
LITERATURE CITED
Coffee, D.R., R.H. Hill, and D.D. Ressel. 1980. Soil Survey of Dallas County, Texas.
U.S. Department of Agriculture, Soil Conservation Service, in cooperation with
Texas Agricultural Experiment Station.
Ehrlich, P.R., D.S. Dobkin, and D. Wheye. 1998. The Birder's Handbook. Simon and
Schuster Inc., New York. 785 p.
McMahan, C.A., R.G. Frye, and K.L. Brown. 1984. The Vegetation Types of Texas
Including Cropland. Texas Parks and Wildlife Department, Wildlife Division,
Austin. 40 p.
National Geographic Society. 1987. Field Guide to the Birds of North America.
National Geographic Society, Washington, D.C. 464 p.
Pulieh, W.M. 1988. The Birds of North Central Texas. Texas A&M University Press,
:'- College Station. 439 p.
Stebbins, R.C. 1985. A Field Guide to Western Reptiles and Amphibians. Houghton
Mifflin Company, Boston. 336 p.
Tennant, A. 1985. A Field Guide to Texas Snakes. Lone Star Books, Houston. 260 p.
Texas Parks and Wildlife Department (TPWD). 1997. Special Species List - Dallas
County. Texas Parks and Wildlife Department, Endangered Resources Branch.
January 13.
" U.S. Fish and Wildlife Service (USFWS). 1979. Unique Wildlife Ecosystems of
Texas. U.S. Fish and Wildlife Service, Department of the Interior, Region Two.
164 p.
U.S. Fish and Wildlife Service. 1998. Southwest Region T&E Lists, Dallas County,
Texas. Interact listing at http://ifw2es.fws.gov/endspes/lists/county.efm. U.S.
Department of Interior, Fish and Wildlife Service, Region 2, Division of
Ecological Services. June 2.
Word Wildlife Fund. 1990. The Official World Wildlife Fund Guide to Endangered
Species of North America. Volumes 1 and 2. Beacham Publishing,
Washington, D.C. 467 p.
World Wildlife Fund. 1992. The Official World Wildlife Fund Guide to Endangered
Species of North America. Volume 3. Beacham Publishing, Washington, D.C.
l180p.
World Wildlife Fund. 1994. The Official World Wildlife Fund Guide to Endangered
Species of North America. Volume 4. Beacham Publishing, Washington, D.C.
2319p.
ATTACHMENT A
Dallas County Species Lists
~.ounry Query http://ifw2es.fws.gov/endspcs/lists/county.cfm
The following species are listed for Dallas County, Texas.
Species Common Name Scientific Name Listing Status
Interior least tern Sterna antillarum Endangered
]3lack-capped vireo Vireo atricapillus Endangered
Mountain plover Charadrius montanus Candidate
06/02/98 08:59:28
· TEXAS PARKS AND WILDLIFE DEPARTMENT
ENDANGERED RESOURCES BRANCH Revised:
SPECIAL SPECIES LIST' 97-01-13
DALLAS COUNTY ~
scientific Name Common Name Federal State
Status Status
~** BIRDS
.BUTEO ALBICAUDATUS -' WHITE-TAILED HAWK T
IENDROICA CERULEA CERULEAN WARBLER
DENDROICA CHRYSOPARIA GOLDEN-CHEEKED WARBLER LE E
EGRETTA RUFESCENS REDDISH EGRET T
'ALCO PEREGRINUS PEREGRINE FALCON E/SA
'ALCO PEREGRINUS ANATUM AMERICAN PEREGRINE FALCON LE E
FALCO PEREGRINUS TUNDRIUS ARCTIC PEREGRINE FALCON E/SA T
~RUS AMERICANA WHOOPING CRANE LE E
.YCTERIA AMERICANA WOOD STORK T
FELECANUS OCCIDENTALIS BROWN PELICAN LE E
3~LEGADIS CHIHI .- WHITE-FACED IBIS T
TERRA ANTILLARUM ATHALASSOS INTERIOR LEAST TERN L~ E
.IREO ATRICAPILLUS BLACK-CAPPED VIREO LE E
** INSECTS
ORDITHON NIGER BLACK LORDITHON ROVE BEETLE
~** MAMMALS
ANIS RUFUS (extirpated) RED WOLF SE E
MYOTIS VELIFER CAVE MYOTIS ~
** REPTILES
~ROTALUS HORRIDUS TIMBER RATTLESNAKE T
PHRYNOSOMA CORNITIVJM TEXAS HORNED LIZARD T
.HAMNOPHIS SIRTALIS ANNECTENS TEXAS GARTER SNAKE
*** VASCULAR PLANTS
"%REX HYALINA TISSUE SEDGE
EXALECTRIS NITIDA GLASS MOUNTAINS CORAL-ROOT
HEXALECTRIS WARNOCKII WARNOCK'S CORAL-ROOT
)des. '
LE, LT ' - Federally Listed Endangered/Threatened
PE,PT - Federally Proposed Endangered/Threatened
'SA,T/SA - Federally Endangered/Threatened by Similarity of Appearance
Cl - Federal Candidate, Category 1; information supports proposing to
list as endangered/threatened
DL,PDL - Federally Delisted/Proposed Delisted
E,T - State Endangered/Threatened
~Decies appearing on these lists do not all share the same probability of
:currence within a county. Some species are migrants or wintering residents
~nly. Additionally, a few species may be historic or considered extirpated
;ithin a county. Species considered extirpated within the state are so flagged
t each list. Each county's revised date reflects the last date any changes or
:visions were made for that county, to reflect current listing statuses and
:axonomy.
APPENDIX D
Cultural Resources Site Assessment
LETTER REPORT:
PEDESTRIAN SURVEY AND GEOARCHEOLOGICAL
INVESTIGATIONS OF A PROPOSED STORM DRAIN ALONG
DENTON CREEK, DENTON COUNTY, TEXAS
by
Steven M. Hunt
David Shanabrook
Submitted to
Brentwood Builders, Inc.
4851 Keller Springs Road
Suite 200
Dallas, Texas 75248
Letter Report Number 31
Geo-Marine, Inc.
550 East Fifteenth Street
Piano, Texas 75074
'- August 25, 1998
INTRODUCTION
As part of a proposed housing development, Brentwood Builders, Inc. (BBI), plan on constructing a
storm drain in the flood plain south of Denton Creek (Figures 1 and 2). As part of the application
process for a Corps of Engineers 404 permit, BBI is required to do a cultural resources investigation of
the approximately 2-acre (ca. 60-x-120 m) direct impact area. BBI then contracted with Geo-Marine,
Inc., of Plano, Texas (GM1) to provide the required cultural resources services. The pedestrian survey
of the impact area was accomplished by Steven Hunt of GMI on August 19, 1998. Geoareheolgical
investigations were undertaken on August 22, 1998, by David Shanabrook (Geologist) and Steven Hunt.
Melissa M. Green of GMI served as Principal Investigator for the project.
The survey area is relatively fiat but undulating, rising approximately 1 m toward a natural levee along
Denton Creek. It is dominated by a mature hardwood forest, consisting primarily of oak trees. The
understory is sparse except for along the bank of Denton Creek and consists of greenbriar and grasses.
The grasses have generally been cropped short. The survey area is mapped within the Frio silty clay,
occasionally flooded, a Mollisol found on the deep and nearly level flood plains of major streams. A
typical prof'fle begins with a brown silty clay about 20 cm deep that is underlain by dark grayish brown
silty clay from 20-61 cm below surface. From 61 to 107 cm below surface a very dark grayish brown
silty clay is encountered, beneath which a grayish brown silty clay is found from 107 to 152 cm below
surface (Ford and Pauls 1980:23-24).
The survey area consists of a small area on the south side of the current channel of Denton Creek just
west of where the Denton Creek's valley joins the valley carved by the Elm Fork of the Trinity River. In.
this area, Denton Creek is oriented roughly east-west while the valley of the Elm Fork of the Trinity is
aligned roughly north-south. · The active channel of Denton Creek in this area is deeply entrenched and
very narrow with extremely steep banks. In the survey area, the surrounding flood plain lies
approximately 4 to 5 meters above the base of the Denton Creek channel and is relatively fiat and smooth
with a noticeable natural levee developed along the lip of the active channel. The south end of the survey
area is just north of an east-west oriented low area or slough which appears to be an abandoned former
channel of the creek.
The near surface geology of the survey area consists of Quaternary-age alluvial deposits consisting of
clays, silts, sands, and gravels unconformably overlying Cretaceous-age limestones, marls, and shales.
The Cretaceous units all dip gently to the east and south into the East Texas Basin and have acted as the
source of some the material in the overlying Quaternary units. Within the survey area, these Cretaceous
Area Shown
!
~o
"'" 'Project Area
(Not to Scale)
I
Figure I. General project area map.
..'~::" 'V: '--~// t / ~ /
~O~SONI C~ON
HOOD
LEE P~WAY
LO
· bedrock units are overlain by a blanket of more recent fluvial and alluvial deposits, the upper portion of
which is believed to be late Holocene in age. Just south of the survey area, there appear to be two
distinct fluvial terraces. Based on the topographic map of the area (USGS 7.5' Carrollton quadrangle,
1959, photorevised 1981), the lower terrace rises 7 meters and the higher stands 15 meters above the
current flood plain of Denton Creek. It is thought that these terraces correspond to the Denton Creek
(lower) and Hickory Creek (higher) Terraces of Ferring (1990a, Figure 9). If so, then deposits of earlier
Holocene and late Pleistocene age may be concealed under the more recent late Holoeene flood plain
units or directly adjacent to them. However, no deposits of this type were directly observed, so they
have either been removed by erosion or lie buried at a considerable .depth. Given the sculpted nature of
the edge of the proposed Denton Creek Terrace in this area and the evidence of a relatively recent
abandoned channel of Denton Creek between the current terrace edge and the survey area, it seems very
._ likely that these units have been removed by erosion.
It is felt that all the sediments observed are of late Holocene age and of fluvial or alluvial origin. Several
studies in this area such as the Gateway locality (Ferring 1990a:60-63), the River Bend site (Peter et al.
1987:14-18), the proposed Dallas Floodway Extension in South Dallas (Cliff et al. 1998), and the East
First Street Bridge site (Peter et al. 1998:44-47), all indicate that it is not unusual to encounter 8 to 14
meters of stratified Holocene depositr in this area. Further, it is not unusual for 3 to 4 meters or more of
- · these deposits to be late Holocene or younger in age (Peter et al. 1998:44-47; Ferring 1990b:Figure 15
and Table 10).
METHODS
Prior to the pedestrian survey, the site files maintained by the Texas Archeological Research Laboratory,
The University of Texas (TARL) were consulted to determine if any previously recorded sites were
known within the survey area. The nearest such site, 41DL31, is a Neo-American (Late Prehistoric)
recorded by R. King Harris along DeForest Road, a short distance east of the property. In addition,
several other sites (such as 41DL252, 41DL275, 41DL295, and 41DL296) have been recorded in similar
environment contexts further west along Denton Creek. Two historic maps of Dallas County, Sam
Street's Map of Dallas County (1900) and the map attached to the original Soil Survey of Dallas County,
Texas (Carter et al. 1924), were consulted to determine the locations of potential historic sites. On both
the Carrollton quadrangle (1959, photorevised 1981) and the aerial photos attached to the Soil Survey of
Demon County, Texas (Ford and Pauls 1980), the survey area is shown in Denton County; however, for
some unknown reason the older maps show the survey area within Dallas County. Perhaps the county
line was slightly redrawn in the intervening period. One structure is shown near the survey area on Sam
Street's Map; although the limited accuracy of this map makes the identification of the exact location
impossible, the structure is believed to correspond to the structure shown on the 1924 soil map
approximately 450 m south-southeast of the survey area along DeForest Road.
The pedestrian survey was conducted by traversing the survey area at approximately 20 m intervals.
Three judgmental shovel tests were excavated during the survey; these units were placed on an apparent
natural levee along Denton Creek. Ail shovel tests were approximately 30 cm in diameter an excavated
in 20-em arbitrary levels to about 40 cm below surface. The extremely hot and dry conditions prevalent
during the summer of 1998 made excavation and screening of these units very difficult. The south bank
of Denton Creek was also examined. Much of the creek bank in this area is at a relatively shallow angle
(ca. 450-50') and covered with leaves and vegetation, giving little visibility. Some recent material, such
as concrete fragments, metal office furniture, and a disintegrating old wagon, were found abandoned on
the surface, but no cultural materials were found through shovel testing or the cut bank examination.
The geoareheological investigation was undertaken through backhoe trenching. The backhoe trenches
(BHT) were approximately 5 m long and dug to a depth of 2.1 to 3 m (7-10 ft), below the depth of the
proposed storm drain. The prof'fle of each unit was examined and interpreted by the geologist.
Excavation of two backhoe trenches was originally proposed, one on the levee along Denton Creek and
one in the flood plain deposits immediately south of the levee (Figure 3). The discovery of bone
fragments of BHT-2, however, required the excavation of a third trench, also along the levee, to test
whether the bone was part of a more extensive deposit.
RESULTS
Pedestrian Survey
Thc pedestrian survey was undertaken to determine if there were any near surface cultural deposits within
the survey area. Given the geomorphic, context of the survey area Despite traversing the survey area at
20 m intervals and the excavation of three shovel tests along the natural levee, the only materials noted
consisted of recent artifacts dumped on the ground surface.
Geoarcheologleal Investigation
Sediment Description and Discussion
The deposits revealed by the trenches appear to record an infilling of the Denton Creek's valley during
the Holocene period. This infflling proceeded at different rates over time and was punctuated by at least
~ ~ Le§¢nd
BHT=2 / ~
~ /'xx,," Project boundaries
I ~ 5 Foot contour intervals
! !
, __/ '-' _j /'~/ 1 Foot contour intervals
,
F //r--.._
// / ,~ (( ,,,~
· r/,.--.. ' \ F.?
I /t__l ,, '"'"J J ~ ~.~.
'i~ \ / I
'2~'' \ I '"J,l'
N
Deforest Road SCALE
Figure 3. Locations of the three archeological backhoe trenches on the proposed Stratford Manor Development.
one period of nondeposition or erosion. This has the effect of both retarding soil development if the rate
of deposition is too high or if erosion is taking place and producing thick sedimentary deposits with
multiple stable surfaces, often marked by buried soil horizons, if organic .accumulation can keep pace
with the rate of deposition and the amount of erosion is minimal. It is likely that all of the trenches
excavated encountered only late Holocene-age deposits based on the nature of the sediments, the
development of the soil profiles, and data from other studies in this area (profile descriptions are
presented at the end of this document).
The typical profile from the survey area has a thin, clay-rich, dark brown, modern soil overlying a 50 to
60 cm thick unit of brown and tan silts and yellow sands which abruptly rests on 1.5 meters or more of
very dark gray to black clay. This dark clay unit appears to be the upper portion of a very thick
paleosol. In the two trenches adjacent to the current Denton Creek channel, the modem soil is overlain
by 20 to 40 cm brown sandy silts and clays. The organically enriched A and B zones within the soils
encountered all exhibited a considerable level of bioturbation by plant roots, worms, and insects and the
lower paleosol possessed significant soil structure with clay, silt, and sand coats on all observed ped
faces. Much of the sediment observed was very f'me grained in nature (clay and sil0 and fairly limey,
judging by the number of zones that had been whitened by calcareous deposits. This would seem
reasonable in light of the type of bedrock (limestones and shales) providing the bulk of sediment supplied
to the Trinity River basin in this area. These f'mer grained deposits lack any sedimentary structures and
all of them would seem typical of deposition in the overbank/backswamp portion of a fluvial flood plain
or possibly in abandoned fluvial channel meanders (i.e., oxbow lakes) much like the slough just south of
the survey area. However, there was also a reasonable amount of coarser clastics in the form of sand
that either was being reworked from older fluvial terrace deposits in this immediate area - the presence of
gravel pits just west of the survey area indicate this is a strong possibility (USGS 7.5' Carrollton
quadrangle, 1959, photorevised 1981) - or brought in from further upstream along either the Denton
Creek or the Elm Fork of the Trinity River. The presence of these coarser clastics in f'ming upward
sequences (i.e., zones 3 and 4 of BHT 2), the abrupt nature of the contact between the clasties and the
underlying paleosol, and the very small amount of sand compared to clay in the sediments would all seem
to indicate that the deposits observed were the product of a sinuous, meandering river or stream which
possessed a very narrow active channel belt which periodically changed location by the process of
avulsion (Cant 1982:125-130, Collinson 1978).
The observed soil proFdes of A-C-2Ab-2Bb or C-2A-2C-3Ab-3Bb would also point to a late Holocene
age for these deposits. None of the deposits showed any level of rubification or of the development of Bt
or E soil horizons common to many older deposits. This lack of pedogenic development could be due to
the deposits being of recent age. However, it is also possible that soil development may have been
severely retarded, first by the constant wetting so common to active fluvial systems; second, by the
frequent, periodic erosion and removal of the organic rich upper members of the soil by flood and stream
action; and third, by the periodic deposition of fresh alluvium on portions of the existing ground surface.
In this regard, it is interesting to note both the thickness of the recent alluvium above the paleosol (90 to
130 em) and the unusually great thickness of the developed A soil horizons in the paleosols themselves
(95 to 148 ctu). This would seetu to indicate that in the survey area Denton Creek's flood plain (and by
extension, the Elm Fork of the Trinity which adjoins it) has continued to aggrade for a long period of
time. This aggradation has taken place at differing rates through time and, as previously noted, there
have been periods of nondeposition or even erosion. The rate of deposition has been low enough at some
points so as to allow for the formation of a thick eumulic paleosol and a thinner more recent "modem"
soil. There was probably a period of nondeposition or even erosion after the formation of the cumulic
paleosol which caused the discoloration of the upper 10 or 20 cm of this unit perhaps due to removal of
organic material, oxidation, or introduction of lighter colored materials into this very dark trait. More
recently, sedimentation rates increased sufficiently at times to bury the cumulic paleosol and even the
modem soil in some places. This last increase in sedimentation could have been due to the close
proximity of the current channel of Denton Creek, a view supported by the coarser nature of some of
these uppermost deposits. All of this would tend to indicate that the "youthful~ appearance of much of
the sediment could be due to factors other than just the age of the deposits being very recent.
Nevertheless, it appears certain that none of the sedimentary deposits observed predate the beginning of
the. Holocene based on the characteristics of the sediments themselves and their strong similarity to dated
deposits from other portions of the Trinity River basin as described by Ferring (1990a) at Gateway Park,
Peter et al. (1987) at the River Bend site, and Peter et al. (1998) at the East First Bridge site. It is likely
that many of these sediments are no older than the Late Holocene.
It is very likely that the upper paleosol encountered in all three trenches (2Ab or 3Ab) corresponds with
the West Fork paleosol described by Yates and Ferring (1986:92-95; Ferring 1990b:36-37, 48, and
Tables 9 and 11). Indeed, the paleosol observed here has tunny of the characteristic features of the West
Fork paleosol - overthickened, dark A soil horizon, a f'me grained calcareous nature, and stratigraphically
positioned at or near the surface of the modem flood plain. This paleosol has yielded dates ranging from
1985 yr B.P. to 528 yr B.P. (Ferring 1990b:Table 11; Peter et al 1987:17-18; Peter et al 1998:46)
placing this soil horizon firmly in the Late Holocene. The range of dates is to be expected given that the
deposition of this unit is time transgressive and, as noted by Ferring (1990b), may even still be
accumulating in some portions of the Trinity River basin. Thus, although it is tempting to see the West
Fork paleosol as a time stratigraphic unit whose formation is linked to regional climatic changes or
regional factors of similar scope, care should be taken in claiming anything more than a Late Holocene
date from its presence since local depositional factors (sediment supply, proximity of the stream channel,
REFERENCES CITED
Cant, D.J.
1982 Fluvial Facies Models and Their Application. Ia Sandstone Depositional Environments, edited
by P. A. Scholle and D. Spearing, pp. 115-137. Memoir 31. American Association of
Petroleum Geologists, Tulsa.
'- Carter, I.T., Jr., A.H. Bauer, J.F. Stroud, W.B. Francis, and T.M. Bushnell
1924 Soil Survey of Dallas County, Texas. Government Printing Office, Washington.
Cliff, M.B., S.M. Hunt, M Prior, S. Gaither, and W. Autin
1998 Archeological, Architectural, Archival, and Geoarcheological Investigations of the Proposed
Dallas Floodway Extension Project, Dallas County, Texas. Miscellaneous Report of
Investigations Number 152. Geo-Marine, Inc., Piano, Texas.
Collinson, J.D.
1978 Alluvial Sediments. In Sedimentary Environments and Facies, edited by H.G. Reading, pp.
'- 15-60. Elsevier, New York.
Fcrrin , C.rt.
1990a The 1989 Iavestigationa at the Aubrey Clovis Site, Texas. Current Research in the Pleistocene
7:3-5.
1990b Late Quaternary Geology and Geoarcheology of the Upper Trinity River Basin, Texas. Field
Trip #11 Guidebook, Goologieal Society of America, Dallas.
Ford, A., and E. Pauls
1980 Soil Survey of Denton County, Texas. U.S. Department of Agriculture, Soil Conservation
Service, in cooperation with the Texas Agricultural Experiment Station.
Peter D.E., B. Ellwood, J. Seheiber, and B. Yates
1987 Test Excavations of the River Bend Site (41TR68). Center for Geoarchaeological Studies,
University of Texas, Arlington.
Peter, D.E., F.B. Largent, Jr., and S.M. Hunt
1998 Cultural Resources Impact Assessment of the Proposed Randol Mill Road Extension, Phase 3,
City of Fort Worth, Tarrant County, Texas. Miscellaneous Report of Investigations No. 159. Geo-
Marine, Inc., Piano, Texas.
Yates, B.C., and C.R. Ferring
1986 The Upper Trinity River Basin. In Assessment of the Cultural Resouces in the Trinity River
Basin, Dallas, Tarrant, andDentonCounties, Texas, edited by B.C. Ya~es and C.R. Ferring,
pp. 12-31. Institute of Applied Sciences, North Texas State University, Denton.
Backhoe Trench Descriptions
Depth Soil Description
(cm) Zone
BHT 1 At south edge of survey area, north of axis of old slough
0-23 A Dark grayish brown (10YR 4/2 dry) silty, sandy, clay; very fu'm; fmc blocky
structure with sand on ped faces; few very small pieoes of gastropod shell;
upper part root bound with grass and wild onions; numerous woody roots and
insect burrows; clear, smooth contact
23-90 C Dark grayish brown to brown (10YR 4/2 to 10YR 5/3) very sandy clay to
clayey fmc grained sand; friable to fu'm; weak fmc blocky structure; heavily
bioturbated with many krotovina filled with light yellowish brown (10YR 6/4)
fmc grained sand; abundant woody roots to 2 em ia size; few gastropod shell
fragments; clear to gradual, smooth contact
90-185 2Ab Black to very dark gray (10YR 2/1 to 10YR 3/1) slightly silty clay; very fu'm
but breaks into small clods easily due to lack of moisture; strong medium to
coarse blocky structure with clay skins on ped faces; many small gastropod
shells and shell fragments; few krotovina filled with material from overlying
zone; few small rounded pebbles; boundary is diffuse (note - a sample of this
zone was taken from between the depths of 90 and 95 cm)
185-214 2Bb Dark gray to dark grayish brown (10YR 4/1 to 10YR 4/2) slightly silty clay;
finn to slightly plastic; blocky structure; abundant gastropod shell fragments
that give zone a speckled look
BHT 2 At south edge of present Denton Creek channel, 50 meters north and 1 meter
higher than BHT 1.
0-43 C Brown to yellowish brown (10YR 5/3 to 10YR 5/4) silty, sandy clay; massive
to very weak blocky; very fa'm; many open and sand ftlled krotovina; many
worm burrows filled with yellow (10YR 7/6) fmc grained sand; few gastropod
shells; abundant rootlets and numerous fmc woody roots; clear, sligthly wavy
boundary.
43-71 2Ab Dark grayish brown (10YR 4/2) slightly sandy clay; firm; weak fmc blocky
structure; heavily whitened with calcareous deposits; abundant fine to medium
sized woody roots; abundant open and sand filled krotovina, many of the open
krotovina are lined with white calcareous deposits; gradual to clear boundary
71- 2C1 Yellowish brown to light yellowish brown (10YR 5/4 to 10YR 6/4) clayey,
121/125 sandy silt that grades downward to a very pale brown (10YR 8/4) very fmc
grained sand with yellowish brown (10YR 5/4) silt laminae; slightly firm to
friable; massive; upper 30 em is noticeably whitened with calcareous deposits;
rootlets ia upper part which decrease in number with depth; clear boundary
121- 2C2 Very pale brown (10YR 7/4) fmc grained, well sorted sand; loose; zone
131/135 thickens from 0 cm 1 meter from north end of trench to 10 cm at south end of
trench; faint traces of bedding which dip south at low angle in wall of trench;
abrupt, slightly wavy boundary
131/135- 3Ab Very dark gray to black (10YR 3/1 to 10YR 2/1) slightly silty clay; very firm;
Backhoe Trench Descriptions
Depth Soil Description
(em) Zone
250 strong medium to coarse blocky structure with clay skins on most and tan silt
coats on a few ped faces; upper 10 to 15 em of zone is brown to yellowish
brown (10YR 5/3 to 10YR 5/4) in color with sand coats on pod faces and
some whitening from calcareous deposits but is identical to remainder of the
zone except for the apparent color alteration; common fmc rootlets; few
rotting tree roots and common open rootlet holes; zone becomes less fu'm and
more plastic with depth; common fragments of gastropod shell; few pieces of
mammal bone at 230 em depth; gradual to diffuse boundary (note - zone
sampled between the depths of 130 and 140 cra)
250-300 3Bb Dark grayish brown (10YR 4/2) silty clay; firm; strong blocky structure with
tan silt and sand coats or clay skins on ped faces; white calcareous deposits on
rootlet traces; common fmc krotovina, most flied with dark soil from
-" overlying zone and few with light colored sand; part mottled with faint orange
iron stain
BHT 3 At south edge of current channel of Denton Creek, 15 meters west of BHT 2
0-21 C Brown (10YR 5/3 dry) sandy silt; hard; massive; abundant rootlets and f'me
woody roots; common krotovina Idled with light brownish yellow sand (10YR
6/4) which give zone a mottled look; gradual boundary
21-60 2A Dark grayish brown (10YR 4/2) slightly sandy clay; very firm; weak blocky
structure with sand coats on ped faces; abundant woody roots up to 2 cm in
size; zone visibly whitened with caleareons deposits; common krotovina, some
f'filed with sand and others with white calcareous linings, clear, smooth
boundary.
60- 2C Layered brown to dark grayish brown (10YR 5/3 to 10YR 4/2) sandy silt and
112/117 light yellowish brown to brownish yellow (10YR 6/4 to 10YR 6/6) silty sand;
friable to loose; silty portions exhibit weak blocky structure while sand is
massive; upper 20 cm silty, next 10 em sandy, next 15 em silty with some
clay, basal portion is well sorted, f'me grained sand; silty portions are visibly
whitened with calcareous deposits; zone extensively bioturbated with common
woody roots; zone faintly laminated particularly basal portion; boundary is
abrupt and slightly wavy.
112/117- 3Ab Black to very dark gray (10YR 2/1 to 10YR 3/1) slightly silty clay; very firm;
260 strong medium blocky structure with clay skins on ped faces; upper 20 em
alterted in color as in BHT 2 being dark grayish brown (10YR 4/2) with sand
coats on ped faces, visible whitening from calcareous deposits and several
large sand filled krotovina; common fragment~ of gastropod shells; some
white calcareous deposits along rootlet traces; with depth, soil structure
weakens with common dark orange decaying rootlets and tan silt filled
krotovina; boundary diffuse
260-315 3Bbea Very dark grayish brown (10YR 3/2) slightly silty clay; firm but more plastic
than zone above; weak coarse blocky structure with clay skins on peals; white
calcareous deposits along rootlet traces; few small calcareous concretions;
common dark orange decaying rootlets