Item 6 - Pecan Creek Development Drainage Study - 2023-0214_reducedDRAINAGE STUDY FOR
TIMARRON CREEK IN SUPPORT OF THE PECAN
CREEK DEVELOPMENT IN
Southlake, Texas
February 14, 2023
Prepared by:
KCE Engineering, LLC
TBPE Firm #16940
Dr. Cuneyt Erbatur, PE, CFM, LEED AP
cuneyt@kce‐eng.com
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 2
Introduction
The Project site is an approximately 2.255‐acre site located on the south side of Zena Rucker Rd.
between Byron Nelson Pkwy and Matthews Ct. in Southlake, Texas, as shown in Appendix A –
Figure 1. The Project site is undeveloped but there is an existing retention pond located on the
property that was designed by Pogue Engineering & Development, Inc. in September of 2005.
Per the construction plans provided in Appendix D, this retention pond was designed with a
normal WSEL of 613.50 and a 100‐year WSEL of 617.30 and a weir outfall.
There are commercial sites to the north of Zena Rucker Rd., Rockenbaugh Elementary School to
the south and west, and single‐family residential to the east. According to the current effective
FIRM 48439C0085K, revised September 25, 2009, there is FEMA floodplain (Zone X) within the
property from Timarron Creek. However, the City of Southlake notified KCE that Halff &
Associates has performed an updated study for the North Central Texas Council of Governments
for the FY 14 Risk MAP Project that includes Timarron Creek and is in the process of becoming
the effective models and mapping for the area. The report and models provided by the City of
Southlake as part of that remapping effort were used as the effective models for the area
although they are not yet approved by FEMA.
The Project is planned to be developed as a commercial development with two (2) buildings and
associated parking and other infrastructure designed by Redinger Group, LLC (RG).
The purpose of this drainage study is to determine the hydrologic and hydraulic impacts of the
proposed development to Timarron Creek, and to determine if the proposed project will cause
any adverse impacts to adjacent or downstream property owners. The City of Southlake defines
adverse impacts as:
No new or increased flooding (0.0 feet) of existing insurable (FEMA) structures (habitable
buildings)
No increase greater than 0.1 feet in the 1, 5, and 100‐year flood elevations over existing
roadways. No increase greater than 0.1 feet and 100‐year flood elevations unless
contained in existing channel, roadway, drainage easement and/or ROW.
Proposed channel velocities for 1, 5, and 100‐year storms cannot exceed the applicable
maximum permissible velocity in Table 3.16 and Table 3.17 of the City of Fort Worth
Stormwater Criteria Manual.
If existing channel velocities exceed maximum permissible velocities, no more than 5%
increase in velocities will be allowed.
No increase in downstream discharges caused by the proposed development that, in
combination with existing discharges, exceeds the existing capacity of the downstream
storm drainage system or existing right‐of‐way.
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 3
Overall Hydrologic Analysis
The City of Southlake provided KCE with the Drainage Study for Zena‐Rucker Road prepared by
Teague Nall & Perkins (TNP), dated December 2014 for the design of the existing culvert under
Zena Rucker Rd. adjacent to the Project site. However, the City only provided KCE with the PDF
of the report and not the HEC‐HMS model used for the analysis, so KCE instead created a HEC‐
HMS model for Timarron Creek watershed to a point just downstream of the Project site to
determine if the proposed project would result in increases in the peak discharges at Timarron
Creek. In addition, the report by TNP indicated the use of an older version of HEC‐HMS (version
3.5) as well as different rainfall data. While this information was correct and the best available
at the time of the study, KCE has used the Atlas 14 rainfall data and HEC‐HMS version 4.9 for this
analysis.
KCE used the onsite topographic survey data provided by Spry Surveyors, LLC, dated 3/2/21 as
well as the 2019 TNRIS contour data and record drawings to determine the existing drainage
areas for the HEC‐HMS model of Timarron Creek to the downstream side of the Project site. At
this location the contributing watershed is approximately 235‐acres, to the 2.2‐acre Project site
comprises approximately 1% of the watershed and this was taken as the Zone of Influence.
The Project site currently includes an existing retention pond that was designed as part of a
commercial development on the north side of Zena Rucker Rd. by Pogue Engineering &
Development Company, Inc., dated 9/19/05. The record drawings are provided in Appendix D.
As part of this proposed Project, the developer is proposing to remove the existing retention
pond to allow for more commercial development.
The existing drainage area map is shown in Appendix A – Figure 2. The main ponds and junctions
are as follows:
Fox_Pond‐1 – the existing detention pond from the Foxborough residential development
on the upstream side Foxborough Lane
Fox_Pond‐2 – the second existing detention pond from the Foxborough residential
development located just upstream of FM 1709
J‐3 – located at the upstream side of the existing commercial drive just to the south of FM
1709
J‐4 – located at the upstream side of Zena Rucker Road
Ex_Pond‐A – the existing retention pond within the Project site
J‐5 – located at the downstream side of the Project site and the Project’s ZOI
The SCS curve number (CN) represents the runoff potential of a given area with the higher the
CN, the greater the runoff potential. Curve numbers were determined based on the hydrologic
soil type and adjusted based on land use. KCE used the USGS Web Soil Survey to determine the
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 4
hydrologic soil types for the drainage areas. KCE calculated the base CN for each drainage area
and then determined the percent impervious based on the existing land uses.
For the proposed conditions CN, KCE used a percent impervious for the Project site of 70% based
on the current proposed site plan by RG. Refer to Appendix A – Figures 2 and 4 for the existing
and proposed land uses, respectively. Refer to Appendix A – Figure 3 for the hydrologic soil map
and refer to Appendix B for the base CN and percent impervious calculations for the existing
conditions. The construction plans are in Appendix E.
The time of concentration is defined as the time required for water to flow from the most
hydraulically remote point of the basin to the design point of interest, in this case to the junction
locations in the HEC‐HMS model. The path of travel is divided into sheet flow, shallow
concentrated flow and open channel flow (or closed storm drain system flow). KCE used the
existing contour data and record drawings to determine the existing time of concentration
calculations, and the proposed plans and grading by RG for the proposed calculations. Refer to
Appendix A – Figures 2 and 4 for the existing and proposed flowpaths, respectively. The time of
concentration calculations are shown in Appendix B, and the proposed storm drain systems are
shown in Appendix E.
Based on the SCS Publication Technical Release (TR‐55), the watershed lag time was calculated
at 60% of the total time of concentration for the subbasin. The watershed lag time is the time
from the center of mass of excess rainfall to the peak rate of storm water runoff. To comply with
the City of Southlake requirements, the rainfall data used is from the iSWM technical manual for
Tarrant County.
Tables 1 and 2 below show the existing and proposed parameters for the Project, and Figures 1
and 2 below show the existing and proposed HEC‐HMS models.
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 5
Figure 1 – Existing HEC‐HMS Model
Table 1 – Existing HMS Input Parameters
Existing Conditions HMS Input Data
Basin Area
(Sq.Mi.)
Area
(acres)
Base
CN
Impervious
Rate
Lag Time
(min)
A 0.003447 2.206 74.0 23% 11.3
OS‐A 0.009934 6.358 73.2 86% 12.2
OS‐1 0.073661 47.143 67.9 50% 18.4
OS‐2 0.144055 92.195 70.4 46% 13.8
OS‐3 0.073464 47.017 69.6 74% 17.1
OS‐4 0.036864 23.593 77.1 44% 13.5
OS‐5 0.026047 16.670 70.3 73% 13.1
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 6
Figure 2 – Proposed HEC‐HMS Model
Table 2 – Proposed HMS Input Parameters
Proposed Conditions HMS Input Data
Basin Area
(Sq.Mi.)
Area
(acres)
Base
CN
Impervious
Rate
Lag Time
(min)
A 0.003447 2.206 74.0 70% 4.5
OS‐A 0.009934 6.358 73.2 86% 12.2
OS‐1 0.073661 47.143 67.9 50% 18.4
OS‐2 0.144055 92.195 70.4 46% 13.8
OS‐3 0.073464 47.017 69.6 74% 17.1
OS‐4 0.036864 23.593 77.1 44% 13.5
OS‐5 0.026047 16.670 70.3 73% 13.1
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 7
Existing Detention Ponds
As previously discuss, there is an existing retention pond within the Project site that was
constructed as part of an upstream commercial development with the construction plans by
Pogue Engineering & Development Company, Inc., dated 9/19/05. Per the record drawings
provided, it appears that the retention pond was designed using the Modified Rational Method,
but KCE was only provided with the drainage area map and not any detention pond design plan
sheets. Based on the drainage area map, the normal WSEL of the pond was supposed to be
613.50 with a 100‐year WSEL of 617.30. The outfall design appears to be a weir and the tailwater
in the adjacent Timarron Creek does not appear to be taken into consideration in the original
design. In addition, there are two (2) detention ponds within the Foxborough residential
development that outfall into Timarron Creek. Please refer to Appendix D for the record
drawings provided to KCE.
KCE used the 2019 TNRIS contour data to determine the elevation‐areas for each of the existing
detention ponds. Although Existing Pond A was supposed to have a normal WSEL of 613.5, at
the time of the survey the WSEL was only 613.0, so KCE used this as the bottom of the storage
available in the retention pond. The pond outfalls for the Foxborough ponds were determined
from the record drawings. For the existing retention pond on the Project site, KCE used the
survey data to determine the pipe outfall and weir overtopping. Since both Foxborough Pond 2
and Existing Pond A outfall into Timarron Creek, the tailwater conditions in Timarron Creek also
impacts the pond outfalls. Tables 4 – 6 below show the elevation‐area‐volume for the existing
ponds, Tables 7 – 8 shows the tailwater elevation‐discharge for Foxborough Pond 2 and Existing
Pond A.
Table 4 – Foxborough Pond 1 Elevation‐
Area‐Volume
Fox_Pond‐1
Elevation
(ft)
Area
(acres)
Inc. Vol.
(acre‐ft)
Cum. Vol.
(acre‐ft)
626.5 0.000 0.000 0.000
628 0.009 0.007 0.007
630 0.337 0.346 0.353
632 0.495 0.832 1.185
634 0.702 1.197 2.382
Table 5 – Foxborough Pond 2 Elevation‐
Area‐Volume
Fox_Pond‐2
Elevation
(ft)
Area
(acres)
Inc. Vol.
(acre‐ft)
Cum. Vol.
(acre‐ft)
623.5 0.000 0.000 0.000
624 0.768 0.192 0.192
625 0.921 0.845 1.037
626 1.020 0.971 2.007
627 1.131 1.076 3.083
628 1.277 1.204 4.287
629 1.785 1.531 5.818
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 8
Table 6 – Existing Pond A Elevation‐Area‐
Volume
Ex_Pond‐A
Elevation
(ft)
Area
(acres)
Inc. Vol.
(acre‐ft)
Cum.
Vol.
(acre‐ft)
613.0 0.311 0.000 0.000
614 0.383 0.347 0.347
615 0.415 0.399 0.746
616 0.475 0.445 1.191
617 0.584 0.530 1.721
618 0.584 0.584 2.305
Table 7 – Foxborough Pond 2 Tailwater
Elevation‐Discharge
Fox Pond 2 Tailwater
RAS XS 11208
Elevation
(ft)
Discharge
(cfs)
623.74 0
623.79 1
624.4 100
624.77 200
625.09 300
625.36 400
625.61 500
626.15 750
627.02 1000
627.9 1250
628.9 1500
629.94 1750
630.51 2000
630.84 2250
631.11 2500
631.35 2800
Table 8 – Existing Pond A Tailwater
Elevation‐Discharge
Ex Pond A Tailwater
RAS XS 10021
Elevation
(ft)
Discharge
(cfs)
610.5 0
610.76 1
612.99 100
614.13 200
614.96 300
615.63 400
616.16 500
617.17 750
617.74 1000
617.93 1250
618.36 1500
618.54 1750
618.71 2000
618.87 2250
619.02 2500
619.19 2800
This existing pond information was input into the HEC‐HMS model for the watershed.
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 9
HEC‐HMS Model
These parameters and detention ponds were input into the United States Army Corps of
Engineers HEC‐HMS (version 4.9) program to determine the peak discharges for the contributing
drainage areas for the required storm events. The routing between Fox_Pond‐1 and Fox_Pond‐
2 was done with the Muskingum‐Cunge method, and the routing between J‐3 and J‐4 was done
with Modified Puls method. Table 9 below shows the Modified Puls routing data used, Table 10
below shows the calculated peak discharges for the required storm events at the HMS junctions
for the existing and proposed conditions, and Tables 11 – 13 show the pond result summaries.
Table 9 – Modified Puls Routing Data
Reach‐2
XS 10950 ‐ XS 10227
Storage
(ac‐ft)
Discharge
(cfs)
0.04 1
0.61 100
0.98 200
1.29 300
1.58 400
1.83 500
2.57 750
3.56 1000
4.66 1250
5.83 1500
7.76 1750
8.84 2000
10.05 2250
Table 10 – Peak Discharges at Junctions
Peak Discharge Comparison
Basin Peak Discharge 5‐Yr (cfs) Peak Discharge 10‐Yr (cfs) Peak Discharge 100‐Yr (cfs)
Ex. Pr. Pr. ‐ Ex. Ex. Pr. Pr. ‐ Ex. Ex. Pr. Pr. ‐ Ex.
A 6 11 5 7 13 6 13 21 8
Ex_Pond‐A 13 NA NA 14 NA NA 58 NA NA
Fox_Pond‐2 303 303 0 373 373 0 626 626 0
J‐3 436 436 0 534 534 0 881 881 0
J‐4 493 493 0 603 603 0 987 987 0
J‐5 539 561 22 659 685 26 1,111 1,111 0
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 10
Based on the results of the HEC‐HMS model, although Existing Pond A did reduce the peak
discharge for the 5‐ and 10‐year storm events, it did not provide any detention for the 100‐year
storm event. There were increases in the peak discharge from the Project site due to the
proposed development, but there was no increase in the 100‐year peak discharge at Timarron
Creek at the ZOI. There were increases in the 5‐ and 10‐year storm events, but those increases
are entirely contained within the existing 100‐year floodplain of Timarron Creek.
Table 11 – Foxborough Pond 1 Results
Fox_Pond‐1
Rain
Event
Peak
Inflow
(cfs)
Peak
Outflow
(cfs)
Peak
Storage
(acre‐
ft)
Peak
Elevation
(ft)
5‐Year 107 95 0.6 630.7
10‐Year 133 117 0.8 631.4
100‐Year 225 192 1.8 633.3
Table 12 – Foxborough Pond 2 Results
Fox_Pond‐2
Rain
Event
Peak
Inflow
(cfs)
Peak
Outflow
(cfs)
Peak
Storage
(acre‐
ft)
Peak
Elevation
(ft)
5‐Year 317 303 1.7 625.8
10‐Year 389 373 2.1 626.1
100‐Year 650 626 3.2 627.2
Table 13 – Existing Pond A Results
Existing Pond A
Rain
Event
Peak
Inflow
(cfs)
Peak
Outflow
(cfs)
Peak
Storage
(acre‐
ft)
Peak
Elevation
(ft)
5‐Year 29 13 1.5 616.5
10‐Year 35 14 1.7 617.0
100‐Year 56 58 2.2 617.8
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 11
Overall Hydraulic Analysis
Timarron Creek is part of the NCTCOG FY14 Risk MAP Project by Halff, dated February of 2016.
It is KCE’s understanding that the report and models associated with this remapping effort are in
the process of becoming the FEMA‐effective models for the watershed but have not yet been
approved. The City of Southlake provided KCE with the HEC‐RAS model of Timarron Creek from
this report to use as the effective model. That model included all of Timarron Creek as well as
several tributaries. However, the Timarron Creek model did not include the Zena Rucker Rd
crossing and had lower peak discharges than those calculated by KCE (950 cfs vs 1,100 cfs). Since
KCE’s peak discharges were higher adjacent to the Project site, KCE created a truncated HEC‐RAS
model of Timarron Creek along Reach 3. KCE also added cross‐sections through the Project site
to model Zena Rucker Rd and to better capture any proposed impacts to the floodplain. The
cross‐sections added are:
101+06 100+75 100+21
The plans in the HEC‐RAS model are as follows:
TIMARRON_CREEK_WATERSHED – the Timarron Creek model by Halff dated February
2016 as part of the NCTCOG FY14 TSDN. This model does not include Zena Rucker Rd.
TIMARRON_CREEK_ROUTING – the Timarron Creek model by Halff dated 2016 as part of
the NCTCOG FY14 TSDN. KCE assumes that this model was used for the Modified Puls
routing data.
TIMARRON_CREEK_FLOODWAY – the Timarron Creek model by Halff dated 2016 as part
of the NCTCOG FY14 TSDN.
KCE_Corrected_MP – KCE saved the TIMARRON_CREEK_WATERSHED model and added
cross‐sections as well as Zena Rucker Rd
KCE_Corrected_Routing – the KCE_Corrected_MP model with the routing data used by
Halff
KCE_Corrected_2 – this is the model used as the existing model for the basis of
comparison. KCE truncated the model from KCE_Corrected_MP and used the higher peak
discharges determined by KCE in the earlier hydrologic analysis. KCE added a rating curve
for the downstream boundary conditions to tie into the effective model
KCE_Concept_Proposed_2 – this is the model used as the proposed model for the basis
of comparison. KCE used the proposed grading by RG dated 11/11/22 to determine the
hydraulic impact of the proposed Project.
The United States Army Corps of Engineers HEC‐RAS (version 6.1) program was used to calculate
the WSEL and velocity within the limits of the study. Tables 14 – 16 below displays the HEC‐RAS
comparison for the required storm events through the Project site. The existing and proposed
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 12
floodplains are shown in Appendix A – Figures 5 and 6, respectively. Refer to Appendix C for the
HEC‐RAS profile and cross‐sections comparison.
Table 14 – 100‐year HEC‐RAS Results
100‐year HEC‐RAS Results
River
Sta
W.S. Elev (ft) Velocity (ft/s)
Ex. Pr. Pr‐Ex Ex. Pr. Pr‐Ex % Diff.
11208 626.52 626.52 0.00 5.53 5.53 0.00 0%
11188 626.60 626.60 0.00 3.70 3.70 0.00 0%
11108
11038 626.51 626.51 0.00 2.38 2.38 0.00 0%
11013 626.43 626.43 0.00 3.21 3.21 0.00 0%
10985
10950 623.40 623.40 0.00 6.04 6.04 0.00 0%
10860 623.07 623.07 0.00 5.13 5.13 0.00 0%
10660 622.31 622.31 0.00 5.09 5.09 0.00 0%
10559 621.18 621.18 0.00 7.26 7.26 0.00 0%
10440 619.99 619.99 0.00 6.33 6.33 0.00 0%
10346 619.59 619.59 0.00 4.68 4.68 0.00 0%
10227 619.37 619.37 0.00 3.59 3.59 0.00 0%
10207
10106 618.59 618.59 0.00 3.65 3.65 0.00 0%
10075 618.18 618.18 0.00 5.43 5.44 0.01 0%
10021 617.92 617.92 0.00 5.36 5.36 0.00 0%
9936 617.24 617.24 0.00 6.59 6.58 ‐0.01 0%
9799 616.83 616.83 0.00 4.70 4.70 0.00 0%
9604 615.55 615.55 0.00 6.71 6.71 0.00 0%
9483 614.72 614.72 0.00 6.60 6.60 0.00 0%
9394 614.42 614.42 0.00 4.86 4.86 0.00 0%
Table 15 – 10‐year HEC‐RAS Results
10‐year HEC‐RAS Results
River
Sta
W.S. Elev (ft) Velocity (fps)
Ex. Pr. Pr‐Ex Ex. Pr. Pr‐Ex % Diff.
11208 625.29 625.29 0.00 6.66 6.66 0.00 0%
11188 624.40 624.40 0.00 6.47 6.47 0.00 0%
11108
11038 624.56 624.56 0.00 2.27 2.28 0.01 0%
11013 624.35 624.35 0.00 3.71 3.71 0.00 0%
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 13
10‐year HEC‐RAS Results
River
Sta
W.S. Elev (ft) Velocity (fps)
Ex. Pr. Pr‐Ex Ex. Pr. Pr‐Ex % Diff.
10985
10950 622.26 622.26 0.00 4.79 4.79 0.00 0%
10860 621.97 621.97 0.00 4.07 4.07 0.00 0%
10660 621.16 621.16 0.00 4.53 4.53 0.00 0%
10559 620.35 620.34 ‐0.01 5.64 5.65 0.01 0%
10440 618.49 618.52 0.03 6.74 6.65 ‐0.09 ‐1%
10346 617.91 617.97 0.06 4.28 4.21 ‐0.07 ‐2%
10227 617.58 617.66 0.08 3.27 3.20 ‐0.07 ‐2%
10207
10106 617.38 617.45 0.07 2.72 2.69 ‐0.03 ‐1%
10075 617.09 617.18 0.09 4.30 4.20 ‐0.10 ‐2%
10021 616.87 616.98 0.11 4.17 4.06 ‐0.11 ‐3%
9936 616.39 616.48 0.09 4.93 5.02 0.09 2%
9799 615.75 615.83 0.08 4.77 4.85 0.08 2%
9604 614.73 614.79 0.06 5.18 5.31 0.13 3%
9483 613.31 613.42 0.11 7.34 7.28 ‐0.06 ‐1%
9394 613.09 613.20 0.11 4.35 4.37 0.02 0%
Table 16 – 5‐year HEC‐RAS Results
5‐year HEC‐RAS Results
River
Sta
W.S. Elev (ft) Velocity (fps)
Ex. Pr. Pr‐Ex Ex. Pr. Pr‐Ex % Diff.
11208 625.09 625.09 0.00 6.30 6.30 0.00 0%
11188 624.22 624.22 0.00 6.10 6.10 0.00 0%
11108
11038 623.36 623.36 0.00 2.61 2.61 0.00 0%
11013 623.07 623.06 ‐0.01 4.27 4.27 0.00 0%
10985
10950 621.81 621.81 0.00 4.41 4.41 0.00 0%
10860 621.52 621.52 0.00 3.74 3.74 0.00 0%
10660 620.78 620.77 ‐0.01 4.08 4.08 0.00 0%
10559 620.07 620.07 0.00 5.01 5.02 0.01 0%
10440 617.98 618.00 0.02 7.10 7.03 ‐0.07 ‐1%
10346 617.36 617.41 0.05 4.10 4.04 ‐0.06 ‐1%
10227 616.99 617.06 0.07 3.13 3.07 ‐0.06 ‐2%
10207
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 14
5‐year HEC‐RAS Results
River
Sta
W.S. Elev (ft) Velocity (fps)
Ex. Pr. Pr‐Ex Ex. Pr. Pr‐Ex % Diff.
10106 616.85 616.93 0.08 2.46 2.43 ‐0.03 ‐1%
10075 616.58 616.67 0.09 4.05 3.94 ‐0.11 ‐3%
10021 616.36 616.47 0.11 3.90 3.78 ‐0.12 ‐3%
9936 615.91 616.01 0.10 4.50 4.59 0.09 2%
9799 615.26 615.36 0.10 4.43 4.49 0.06 1%
9604 614.27 614.38 0.11 4.74 4.80 0.06 1%
9483 612.83 612.91 0.08 7.10 7.21 0.11 2%
9394 612.58 612.68 0.10 4.07 4.13 0.06 1%
Based on the comparison of the existing conditions to the proposed conditions for the 100‐year
peak discharges, there is no change in the WSEL and only one cross‐section (XS 100+75) with a
slight increase in velocity of 0.01‐fps. At this cross‐section, the velocity is less than 6‐fps and the
slight increase would not result in any erosive velocities, so it is not considered an adverse impact.
There were increases in the 10‐ and 5‐year storm peak discharges because of removing the
existing retention pond, so there was also a corresponding increase in the WSEL adjacent to the
Project site with the largest increase for both storms equal to 0.11‐ft. This increase dissipates
approximately 300‐ft upstream of Zena Rucker Rd. However, any increase in the 10‐ or 5‐year
WSEL is entirely contained within the existing 100‐year floodplain. There are also increases and
decreases in velocity, but no increase in velocity of more than 2%.
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Page | 15
Conclusions
This drainage study was performed to determine if the proposed Project would cause any
adverse impacts to adjacent properties per the City of Southlake criteria. Although the removal
of the existing retention pond does cause an increase in the peak discharges for the 10‐ and 5‐
year storm events, there is no change to the 100‐year peak discharge to Timarron Creek as a
result of this proposed Project.
The results of the hydraulic analysis show that the proposed grading does not cause any increase
in the 100‐year WSEL and only minor changes to the velocity. There are increases in the WSEL
for the 10‐ and 5‐year storm events, but those increases are contained within the existing 100‐
year floodplain. There are minor fluctuations in velocity as a result of the proposed Project but
no increase of more than 2%.
Based on the results of the drainage study, the proposed Project would not result in any adverse
impacts to other properties per the City of Southlake definition.
If you have any questions or comments, please feel free to call.
Sincerely,
Dr. Cuneyt Erbatur, PE, CFM, LEED AP
Principal
a Texas limited liability corporation
TBPE Reg. No. F‐16940
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendices
Appendix A – Figures
$+
Project Location
Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China (Hong Kong), Esri Korea, Esri (Thailand), NGCC, (c)
OpenStreetMap contributors, and the GIS User Community
0 1 2Miles
ZENA RUCKER
NOVEMBER 2022
1 inch = 1 miles
LOCATIONMAP
FIGURE 1±
Legend
$+Location
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Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix B – Hydrologic Data
Basin NameCalculated LongestFlowpath (ft) (1)Length (ft) (2)Slope (ft/ft) (3)Surface Type (4)Manning's n (5)TO (min) (6)Length (ft) (7)Slope (ft/ft) (8)Surface Type (9)K (10)TS (min) (11)Length (ft) (12)Slope (ft/ft) (13)Manning's n (14) X-Section TypeArea (ft2) (15)WP (ft) (16)Channel Velocity (f/s) (17)TH (min) (19)A (EX)476 100 0.010 Dense Grass 0.240 17.03 126 0.020 unpaved16.1 0.92 2500.050Channel5.00 0.83Total TO (min)=17.03Total TS (min)=0.92Total TH (min)=0.8318.79 11.3A (PR)387 50 0.030 Dense Grass 0.240 6.30 87 0.017paved20.3 0.54 2500.013Conduit6.00 0.69Total TO (min)=6.30Total TS (min)=0.54Total TH (min)=0.697.54 4.5OS-A990 100 0.010 Dense Grass 0.240 17.03 298 0.020paved20.3 1.72 5920.013Conduit6.00 1.64Total TO (min)=17.03Total TS (min)=1.72Total TH (min)=1.6420.40 12.2OS-12399 100 0.010 Dense Grass 0.240 17.03 1585 0.013paved20.3 11.57 7140.013Conduit6.00 1.98Total TO (min)=17.03Total TS (min)=11.57Total TH (min)=1.9830.59 18.4OS-22553 100 0.020 Dense Grass 0.240 12.91 164 0.049 unpaved16.1 0.77 22890.013Conduit6.00 6.36587 0.027paved20.3 2.92Total TO (min)=12.91Total TS (min)=3.68Total TH (min)=6.3622.95 13.8OS-32858 100 0.020 Dense Grass 0.240 12.91 621 0.013 unpaved16.1 5.65 21370.013Conduit6.00 5.94286 0.003paved20.3 3.97Total TO (min)=12.91Total TS (min)=9.62Total TH (min)=5.9428.46 17.1OS-41107 100 0.020 Dense Grass 0.240 12.91 1007 0.012 unpaved16.1 9.53 00.013Conduit6.00 0.00Total TO (min)=12.91Total TS (min)=9.53Total TH (min)=0.0022.44 13.5OS-51648 100 0.010 Dense Grass 0.240 17.03 138 0.014paved20.3 0.94 14100.013Conduit6.00 3.92Total TO (min)=17.03Total TS (min)=0.94Total TH (min)=3.9221.89 13.1Basin DataOverland Flow Shallow Concentrated Flow Channel/Street FlowTime of Conc. Calc. (min) (20)Lag Time (min) (22) TRAVEL TIME CALCULATIONSLag_Time_Calculations
FID Label Acres HYDRO CN A*CN
14 A 2.2064199 C 74 163.2751
33 OS‐1 0.0633343 B 61 3.863392
34 OS‐1 13.8572998 B 61 845.2953
37 OS‐1 0.0122279 B 61 0.745902
38 OS‐1 14.9941998 B 61 914.6462
35 OS‐1 0.540658 C 74 40.00869
36 OS‐1 3.1405101 C 74 232.3977
32 OS‐1 14.5351 D 80 1162.808
Sub‐Total OS‐1 47.1433299 67.9 3199.765
2 OS‐2 0.831757 B 61 50.73718
3 OS‐2 30.4342995 B 61 1856.492
4 OS‐2 0.573703 B 61 34.99588
8 OS‐2 0.916689 B 61 55.91803
9 OS‐2 1.24045 B 61 75.66745
11 OS‐2 2.0760801 B 61 126.6409
5 OS‐2 3.2020199 C 74 236.9495
6 OS‐2 0.456837 C 74 33.80594
7 OS‐2 9.1315403 C 74 675.734
10 OS‐2 20.6396008 C 74 1527.33
0 OS‐2 0.380724 D 80 30.45792
1 OS‐2 22.3110008 D 80 1784.88
Sub‐Total OS‐2 92.1947014 70.4 6489.61
17 OS‐3 1.87537 B 61 114.3976
18 OS‐3 3.0882599 B 61 188.3839
23 OS‐3 18.9761009 B 61 1157.542
20 OS‐3 1.66983 C 74 123.5674
21 OS‐3 2.73417 C 74 202.3286
22 OS‐3 1.66508 C 74 123.2159
15 OS‐3 5.9363899 D 80 474.9112
16 OS‐3 5.6914401 D 80 455.3152
19 OS‐3 5.38024 D 80 430.4192
Sub‐Total OS‐3 47.0168808 69.6 3270.081
31 OS‐4 11.4361 C 74 846.2714
29 OS‐4 7.1963601 D 80 575.7088
30 OS‐4 4.9603701 D 80 396.8296
Sub‐Total OS‐4 23.5928302 77.1 1818.81
25 OS‐5 0.261956 B 61 15.97932
26 OS‐5 2.00003 B 61 122.0018
28 OS‐5 4.0981302 B 61 249.9859
EXISTING BASE CN CALCS
FID Label Acres HYDRO CN A*CN
EXISTING BASE CN CALCS
27 OS‐5 6.8175602 C 74 504.4995
24 OS‐5 3.49245 D 80 279.396
Sub‐Total OS‐5 16.6701264 70.3 1171.863
12 OS‐A 0.394995 B 61 24.0947
13 OS‐A 5.9625201 C 74 441.2265
Sub‐Total OS‐A 6.3575151 73.2 465.3212
FID Label Acres CATEGORY Imp. Rate A*Imper.
25 A 0.0534948 Open Space 0% 0
26 A 0.116541 Open Space 0% 0
27 A 1.52161 Open Space 0% 0
24 A 0.0024351 ROW 100% 0.0024351
28 A 0.512333 Water 100% 0.512333
Sub‐Total A 2.2064139 23% 0.5147681
68 OS‐1 1.72131 Commercial 85% 1.4631135
67 OS‐1 6.6884799 ROW 100% 6.6884799
70 OS‐1 3.9716799 Single family 38% 1.50923836
71 OS‐1 12.8950005 Single family 38% 4.90010019
72 OS‐1 13.1329002 Single family 38% 4.99050208
73 OS‐1 0.244078 Single family 38% 0.09274964
74 OS‐1 4.5871401 Single family 38% 1.74311324
75 OS‐1 2.8101101 Single family 38% 1.06784184
69 OS‐1 1.0927 Water 100% 1.0927
Sub‐Total OS‐1 47.1433987 50% 23.5478387
1 OS‐2 0.262892 Commercial 85% 0.2234582
2 OS‐2 0.75545 Commercial 85% 0.6421325
3 OS‐2 0.0238111 Commercial 85% 0.02023944
4 OS‐2 0.0155065 Commercial 85% 0.01318053
20 OS‐2 0.219292 Commercial 85% 0.1863982
8 OS‐2 0.751487 Open Space 0% 0
19 OS‐2 0.679379 Open Space 0% 0
0 OS‐2 9.1967802 ROW 100% 9.1967802
9 OS‐2 15.2726002 Single family 38% 5.80358808
10 OS‐2 28.9571991 Single family 38% 11.0037357
11 OS‐2 3.2439101 Single family 38% 1.23268584
12 OS‐2 8.3350096 Single family 38% 3.16730365
13 OS‐2 0.0128131 Single family 38% 0.00486898
14 OS‐2 1.59552 Single family 38% 0.6062976
15 OS‐2 12.7606001 Single family 38% 4.84902804
16 OS‐2 3.2681701 Single family 38% 1.24190464
17 OS‐2 3.8510301 Single family 38% 1.46339144
18 OS‐2 0.908433 Single family 38% 0.34520454
5 OS‐2 0.0105296 Water 100% 0.0105296
6 OS‐2 0.676905 Water 100% 0.676905
7 OS‐2 1.39741 Water 100% 1.39741
Sub‐Total OS‐2 92.1947278 46% 42.0850421
30 OS‐3 0.11769 Commercial 85% 0.1000365
31 OS‐3 0.139737 Commercial 85% 0.11877645
32 OS‐3 0.783233 Commercial 85% 0.66574805
33 OS‐3 1.25266 Commercial 85% 1.064761
EXISTING IMPERVIOUS RATE CALCS
FID Label Acres CATEGORY Imp. Rate A*Imper.
EXISTING IMPERVIOUS RATE CALCS
34 OS‐3 1.73043 Commercial 85% 1.4708655
35 OS‐3 3.1043301 Commercial 85% 2.63868059
36 OS‐3 2.8582799 Commercial 85% 2.42953792
46 OS‐3 0.0092201 Commercial 85% 0.00783709
49 OS‐3 3.97437 Commercial 85% 3.3782145
37 OS‐3 0.0004938 Open Space 0%0
48 OS‐3 0.273162 Open Space 0%0
29 OS‐3 16.9055996 ROW 100% 16.9055996
40 OS‐3 1.7948999 Single family 38% 0.68206196
41 OS‐3 0.308126 Single family 38% 0.11708788
42 OS‐3 0.137694 Single family 38% 0.05232372
43 OS‐3 0.0184382 Single family 38% 0.00700652
44 OS‐3 7.8032598 Single family 38% 2.96523872
45 OS‐3 5.6909699 Single family 38% 2.16256856
47 OS‐3 0.112334 Single family 38% 0.04268692
38 OS‐3 0.0015103 Water 100% 0.0015103
39 OS‐3 0.0004086 Water 100% 0.0004086
Sub‐Total OS‐3 47.0168462 74% 34.8109504
60 OS‐4 1.62187 Commercial 85% 1.3785895
61 OS‐4 3.8290801 Commercial 85% 3.25471809
66 OS‐4 4.9914699 Commercial 85% 4.24274942
63 OS‐4 1.00445 Open Space 0%0
64 OS‐4 9.3129597 Open Space 0%0
59 OS‐4 0.600276 ROW 100% 0.600276
62 OS‐4 0.567248 Single family 38% 0.21555424
65 OS‐4 1.66544 Single family 38% 0.6328672
Sub‐Total OS‐4 23.5927937 44% 10.3247544
51 OS‐5 1.01141 Commercial 85% 0.8596985
52 OS‐5 1.04506 Commercial 85% 0.888301
53 OS‐5 1.24884 Commercial 85% 1.061514
54 OS‐5 4.6800299 Commercial 85% 3.97802542
55 OS‐5 3.5502901 Commercial 85% 3.01774659
57 OS‐5 0.0192527 Open Space 0%0
50 OS‐5 0.558076 ROW 100% 0.558076
56 OS‐5 3.80831 Single family 38% 1.4471578
58 OS‐5 0.748846 Single family 38% 0.28456148
Sub‐Total OS‐5 16.6701147 73% 12.0950808
22 OS‐A 5.6982498 Commercial 85% 4.84351233
23 OS‐A 0.0604634 Open Space 0%0
21 OS‐A 0.598798 ROW 100% 0.598798
Sub‐Total OS‐A 6.3575112 86% 5.44231033
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix C – Hydraulic Data
0500100015002000605610615620625630TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2/14/2023 2) KCE_Ex 2/14/2023 Main Channel Distance (ft)Elevation (ft)LegendWS 100yr - KCE_PrWS 100yr - KCE_ExWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGroundGroundTIMMARON CREEK 3
0100200300400500600622624626628630632634636TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 11208 OVERBANK ELEVATIONS FROM 2019 LIDAR, CHANNEL FROM SURVEY SECTIONStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0100200300400500600700622624626628630632634636TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 11188 OVERBANK ELEVATIONS FROM LIDAR 2019, CHANNEL ELEVATIONS FROM SURStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExIneff - KCE_ExBank Sta - KCE_ExGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr
0100200300400500600700620622624626628630632634636TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 11108 Culv FM 1709 CROSSING. SEE NOTES:Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_Pr- KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_Pr- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr0100200300400500600700618620622624626628630632634TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 11038 OVERBANK ELEVATIONS FROM LIDAR 2019, CHANNEL ELEVATIONS FROM SURStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_Pr- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr
0100200300400500600700616618620622624626628630632634TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 11013 OVERBANK ELEVATIONS FROM LIDAR 2019, CHANNEL ELEVATIONS FROM SURStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_Pr- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr0100200300400500600700616618620622624626628630632634TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10985 Culv PECAN CREEK DEVELOPMENT CROSSINGStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_Ex- KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_Pr- KCE_Pr- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr
0100200300400500600700616618620622624626628630TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10950 OVERBANK ELEVATIONS FROM LIDAR 2019, CHANNEL ELEVATIONS FROM SURStation (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExIneff - KCE_ExBank Sta - KCE_ExGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr0100200300400500600700614616618620622624626628630TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10860 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
0100200300400500600700800614616618620622624626628630TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10660 Station (ft)Elevation (ft)LegendWS 100yr - KCE_PrWS 100yr - KCE_ExWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0100200300400500614616618620622624626TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10559 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_ExWS 10yr - KCE_PrWS 5yr - KCE_ExWS 5yr - KCE_PrGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
0100200300400500614616618620622624626TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10440 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0100200300400500612614616618620622624626TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10346 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
0100200300400500612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10227 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr0100200300400500610612614616618620622624626TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10207 Culv Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_Pr- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr
0100200300400500600610612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10106 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr0100200300400500600610612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10075 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
0100200300400500600610612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 10021 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0100200300400500600700800608610612614616618620622624626TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 9936 Station (ft)Elevation (ft)LegendWS 100yr - KCE_PrWS 100yr - KCE_ExWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_Ex- KCE_ExGround - KCE_ExIneff - KCE_ExBank Sta - KCE_Ex- KCE_PrGround - KCE_PrIneff - KCE_PrBank Sta - KCE_Pr
0100200300400500600608610612614616618620622TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 9799 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0100200300400500600608610612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 9604 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
0100200300400500600700606608610612614616618620622624TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 9483 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr0200400600800606608610612614616618620622TIMARRON_CREEK_WATERSHED Plan: 1) KCE_Pr 2) KCE_Ex River = TIMMARON CREEK Reach = 3 RS = 9394 Station (ft)Elevation (ft)LegendWS 100yr - KCE_ExWS 100yr - KCE_PrWS 10yr - KCE_PrWS 10yr - KCE_ExWS 5yr - KCE_PrWS 5yr - KCE_ExGround - KCE_ExBank Sta - KCE_ExGround - KCE_PrBank Sta - KCE_Pr
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix D – Record Drawings
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Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix E – Survey and Construction Plans
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Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix F – Environmental Report
20 January 2023
Mr. Clayton Redinger, P.E.
Redinger Group, LLC
250 Miron Drive
Southlake, Texas 76092
Re: Pecan Creek Business Park - Waters of the United States Delineation
Approximately 2.5 acres located at the northwestern corner of Zena Rucker Road and Matthews Court in
the City of Southlake, Tarrant County, Texas.
Dear Mr. Redinger,
Integrated Environmental Solutions, LLC (IES) performed a site survey to identify any aquatic features that meet a
definition of a water of the United States on approximately 2.5 acres located at the northwestern corner of Zena
Rucker Road and Matthews Court in the City of Southlake, Tarrant County, Texas (Attachment A, Figure 1). This
report will ultimately assess and delineate potentially jurisdictional aquatic features to ensure compliance with Clean
Water Act (CWA) Sections 401 and 404.
INTRODUCTION
Waters of the United States are protected under guidelines outlined in CWA Sections 401 and 404, in Executive
Order (EO) 11990 (Protection of Wetlands), and by the review process of the Texas Commission on Environmental
Quality (TCEQ). Agencies that regulate impacts to the nation’s water resources within Texas include the U.S. Army
Corps of Engineers (USACE), the U.S. Environmental Protection Agency (USEPA), the U.S. Fish and Wildlife Service
(USFWS), and the TCEQ. The USACE has the primary regulatory authority for enforcing CWA Section 404
requirements for waters of the United States.
The decision for whether a CWA Section 404 permit is required on a property is determined if there are waters of
the United States present and the extent of losses of those features. The USACE and USEPA have gone through
rulemaking to define what is a water of the United States, independently and jointly, several times since the initial
CWA. The longest standing definitions of waters of the United States were those published in 1986; however, these
definitions were challenged in 2001 and 2007 U.S. Supreme Court decisions. Since then, both the Obama and Trump
administration completed rulemaking to modify the definitions of waters of the United States in the Clean Water
Rule in 2016 and the Navigable Water Protection Rule (NWPR) in 2020. A recent federal district court decision in
Arizona struck down the NWPR but was silent on which definitions of waters of the United States would replace it.
As of the date of this letter report, the USACE Fort Worth District has provided verbal guidance that the USACE will
be utilizing the pre-2015 definitions (i.e., 1986 definitions combined with the Rapanos and Carabell U.S. Supreme
Court decisions) to define waters of the United States. USEPA has indicated that the pre-2015 definitions will be in
place until new definitions have been developed as part of the new definitions rulemaking process that was started
in June 2021, prior to the Arizona court decision.
Mr. Clayton Redinger, P.E.
Pecan Creek Business Park - Waters of the United States Delineation
20 January 2023 Page 2
1986 Waters of the United States Definitions and Rapanos Decision
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.
Waters of the United States are defined in 33 CFR 328.3 (a), 13 November 1986, as:
1. All waters which are currently used, or were used in the past, or may be susceptible to use in interstate or
foreign commerce, including all waters which are subject to the ebb and flow of the tide;
2. All interstate waters including interstate wetlands;
3. All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats,
sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use,
degradation, or destruction of which could affect interstate or foreign commerce including any such waters:
• Which are or could be used by interstate or foreign travelers for recreational or other purposes; or
• From which fish or shellfish are or could be taken and sold in interstate or foreign commerce; or
• Which are used or could be used for industrial purposes by industries in interstate commerce;
4. All impoundments of waters otherwise defined as waters of the United States under the definition;
5. Tributaries of waters identified in paragraphs (a)(1)-(4) of this section;
6. The territorial seas;
7. Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs
(a)(1)-(6) of this section.
On 05 June 2007, the USACE and the USEPA issued joint guidance on delineation of waters on the United States
based on the U.S. Supreme Court decisions in Rapanos and Carabell. Under this guidance, potential waters of the
United States have been classified as traditional navigable waters (TNW), relatively permanent waters (RPW) (i.e.,
having flow most of the year or at least seasonally), or non-RPWs. This guidance states that TNWs and RPWs and
contiguous or adjacent wetlands to these aquatic features are waters of the United States. Wetlands that are
bordering, contiguous, or neighboring another water of the United States is considered adjacent. Additionally,
wetlands that are within the 100-year floodplain of another water of the United States are also considered adjacent.
Non-RPWs, wetlands contiguous or adjacent to non-RPWs, and isolated wetlands must undergo a “significant nexus”
test on a case-by-case basis to determine the jurisdictional nature of these aquatic features. Under the “significant
nexus” test a water feature must have substantial connection to a TNW by direct flow, or by indirect biological,
hydrologic, or chemical connection. Under the “significant nexus” test the USACE District Engineer must submit the
jurisdictional determination (JD) to the regional USEPA office, which makes the decision whether to move the JD to
Headquarters USACE to make the final determination.
This guidance does not void the January 2001 decision of the U.S. Supreme Court in Solid Waste Agency of Northern
Cook County (SWANCC) v. USACE which disallowed regulation of isolated wetlands under the CWA 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. However, the new guidance does require that the
“significant nexus” test be performed in addition to an analysis of other potential interstate commerce uses for
isolated waters.
Mr. Clayton Redinger, P.E.
Pecan Creek Business Park - Waters of the United States Delineation
20 January 2023 Page 3
METHODOLOGY
Prior to conducting fieldwork, the U.S. Geological Survey (USGS) topographic map (Attachment A, Figures 2A and
2B), the Soil Survey of Tarrant County, Texas, and the U.S. Department of Agriculture (USDA) Natural Resources
Conservation Service (NRCS) digital soil databases for Tarrant County (Attachment A, Figure 3), the Federal
Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) (Attachment A, Figure 4), and recent and
historic aerial photographs of the proposed survey area were studied to identify possible aquatic features that could
meet the definition of waters of the United States and areas prone to wetland development. Mr. Lane Pressler and
Mr. Rafael Gomez of IES conducted the delineation in the field in accordance with the USACE procedures on 17
January 2023.
Wetland determinations and delineations were performed on location using the methodology outlined in the 1987
Corps of Engineers Wetland Delineation Manual and the Regional Supplement to the Corps of Engineer Wetland
Delineation Manual: Great Plains Region (Version 2.0). The presence of a wetland is determined by the positive
indication of three criteria (i.e., hydrophytic vegetation, hydrology, and hydric soils). Potential jurisdictional
boundaries for other water features (i.e., non-wetland) were delineated in the field at the ordinary high-water mark
(OHWM). The 33 CFR 328.3 (c)(7) defines OHWM as the line on the shore established by the fluctuations of water
and indicated by physical characteristics such as a clear, 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
that consider the characteristics of the surrounding areas.
Water feature boundaries were recorded on a Trimble GeoExplorer XT Global Positioning System (GPS) unit capable
of sub-meter accuracy. Photographs were also taken at representative points within the survey area (Attachment
B). Historic aerial photographs, from Environmental Data Resources, Inc. (EDR), were used in the jurisdictional
determination of some aquatic features, are included in Attachment C.
RESULTS
Background Review
Topographic Setting
The USGS topographic map (Colleyville 7.5’ Quadrangle 1959, revised 1982) illustrates no blue line features within
the survey area; however, one feature is directly to the east (see Attachment A, Figure 2A). The 2022 Colleyville
7.5’ Quadrangle map illustrates the conditions similarly (see Attachment A, Figure 2B). The overall site topography
was illustrated with slopes-oriented northwest-to-southeast. The maximum site elevation was approximately 620
feet above mean sea level (amsl).
Soils
The USDA NRCS Web Soil Survey identified one soil map unit within the survey area, Rader fine sandy loam, 0 to 3
percent slopes. This soil map unit was not listed as a hydric soil on the Hydric Soils of Texas list prepared by the
National Technical Committee for Hydric Soils (accessed 17 January 2023, Tarrant County, Texas) (see Attachment
A, Figure 3). Hydric soils are described as soils that are sufficiently wet in the upper part to develop anaerobic
conditions during the growing season.
FEMA FIRM
The FEMA FIRM (Tarrant County; Map Panel 48439C0085K and 48439C0095K; effective 25 September 2009) shows
most of the survey area to be within Zone X (Areas of 0.2 percent annual chance flood; areas of 1 percent annual
chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas
protected by levees from 1 percent annual chance flood). A small area along the western border is within Zone X
(Areas determined to be outside the 0.2 percent annual chance floodplain) (see Attachment A, Figure 4).
Historic Aerial Photographs
Historic aerial photographs from an aerial photograph decade package from EDR were also reviewed to understand
the sequence of events that have occurred in the survey area (see Attachment C). The following paragraphs provide
a description of the aerial photographs based on site conditions:
Mr. Clayton Redinger, P.E.
Pecan Creek Business Park - Waters of the United States Delineation
20 January 2023 Page 4
1942-1979 – The survey area is characterized as an active agricultural property comprised of plowed fields
and pastureland. A large drainage channel is depicted outside the survey area near the eastern boundary.
1984-1995 – A building has been constructed in the northeastern corner.
2006-2020 – The building has been removed and a pond has been constructed in its place.
Weather History
The weather history for Wunderground.com W5JP weather station (KTXSOUTH110) recorded no precipitation during
the 7-day period and no precipitation during the 30-day period, prior to the site visit.
Field Investigation
The survey area was characterized as a fallow agricultural property. One vegetation community was observed:
pastureland. The pastureland consisted almost entirely of Bermudagrass (Cynodon dactylon) with bushy bluestem
(Andropogon glomeratus), and Johnsongrass (Sorghum halepense) along the pond edge. Sugarberry (Celtis
laevigata), honey locust (Gleditsia triacanthos), greenbrier (Smilax bona-nox), and poison ivy (Toxicodendron
radicans) were also observed in the fence lines.
Water from the survey area flows southeast into an unnamed tributary of Big Bear Creek. Big Bear Creek flows into
Bear Creek. Bear Creek flows into West Fork Trinity River which ultimately flows in the Trinity River, a TNW. Table
1 and the following paragraphs detail the aquatic features identified within the survey area at the time of evaluation
(Attachment A, Figure 5).
Table 1. Aquatic Features Identified within the Survey Area
Water
Identification Hydrology Characteristics
Post-Rapanos
Water Classification
33 CFR
328.3
Definition
Area
(Acre)
Length
(Linear Feet)
Pond 1 Semi-Permanently Inundated Isolated --- 0.37 ---
Pond 1 was identified as an off channel, isolated, artificially excavated pond in the eastern region. Pond 1 was
constructed sometime between October 2005 and 2006 to capture stormwater from nearby roads and buildings.
The pond’s limits were identified and delineated by OHWM characteristics that included a natural line impressed in
the bank, a wrack line, and water line. No features with OHWM characteristics were observed entering or exiting
the ponds at the time of evaluation. A storm drain was observed feeding the pond from Zena Rucker Road to the
north. A culvert spillway was also observed along the east side of the pond. A review of recent and historical aerial
photographs indicated that Pond 1 has minor fluctuations in surface water elevation, and as such, it is IES’s
professional opinion that it would be considered semi-permanently inundated.
POTENTIAL JURISDICTIONAL ASSESSMENT
The 05 June 2007 USACE and USEPA jointly published instructional guidebook is intended to provide the USACE field
staff a national standard operating procedure for conducting jurisdictional determinations. The guidebook was
prepared by combining all prior applicable provisions, regulations, statutes, and case laws pertaining to the CWA.
All terms, definitions, and conclusions regarding the jurisdictional nature of the aquatic features used within this
report are derived directly, as they are practiced, from the guidance. The following outlines the applicable
interpretations of the guidance appropriate for this situation. Table 1 provides an overview of the jurisdictional
assessment of the aquatic features under the 1986 Waters of the United States definitions and the Rapanos decision
(see Attachment A, Figure 5).
Non-Jurisdictional Features – Pond 1
Based on evidence, Pond 1 was created in an upland setting by excavating a depression and placing earthen fill across
the natural gradient of the landscape in a manner to collect and redirect upslope sheet flow and stormwater with
no signs of previous jurisdictional features in the vicinity. Under the 2007 guidance:
Pond 1 would not be subject to jurisdiction under CWA Section 404, by definition, as it;
Mr. Clayton Redinger, P.E.
Pecan Creek Business Park - Waters of the United States Delineation
20 January 2023 Page 5
• is not a natural pond, impoundment of waters, or waters as defined in paragraphs (a)(1)-(7) of the CWA 33
CFR 328.3;
• is not a TNW or wetland adjacent to a TNW, nor are they non-navigable tributaries of a TNW with relatively
permanent flow or wetlands that abut such tributaries; and
• as clarified under 33 CFR 323.2 (b), The term lake … As used in this regulation, the term does not include
artificial lakes or ponds created by excavating and/or diking dry land to collect and retain water for such
purposes as stock watering, irrigation, settling basins, cooling, and rice growing.
Furthermore, no evidence that this pond was utilized for recreational or commercial purposes was observed. As
such, this pond does not provide interstate commerce and would not be subject to jurisdiction under CWA Section
404.
CONCLUSIONS
To summarize the delineation a pond was identified and delineated within the survey area. Under the 1986 waters
of the United States definitions and the Rapanos decision, Pond 1 would not be considered jurisdictional as it was
a man-made, isolated feature on the landscape. As such, this feature would not be regulated under CWA Section
404.
This delineation is based on professional experience in the approved methodology and from experience with the
USACE Fort Worth District regulators; however, this delineation does not constitute a jurisdictional determination
of waters of the United States. This delineation has been based on the professional experience of IES staff and our
interpretation of USACE regulations at 33 CFR 328.3, the joint USACE/USEPA guidance regarding the Rapanos and
Carabell decisions and the Regulatory Guidance Letter (RGL) 08-02. While IES believes our delineation to be
accurate, final authority to interpret the regulations lies solely with the USACE and USEPA. The USACE Headquarters
in association with the USEPA often issue guidance that changes the interpretation of published regulations.
USACE/USEPA guidance issued after the date of this report has the potential to invalidate the report conclusions
and/or recommendations, which may create the need to reevaluate the report conclusions. IES has no regulatory
authority, as such, proceeding based solely upon this report does not protect the Client from potential sanction or
fines from the USACE/USEPA. The Client acknowledges that they can submit this report to the USACE for a
preliminary jurisdictional determination for concurrence prior to proceeding with any work within aquatic features
located on the survey area. If the Client elects not to do so, then the Client proceeds at their sole risk.
IES appreciates the opportunity to work with you and Redinger Group, LLC on this project, and we 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 myself or Rudi Reinecke at 972-562-7672 (lpressler@intenvsol.com or rreinecke@intenvsol.com).
Sincerely,
Integrated Environmental Solutions, LLC.
Mr. Lane Pressler
Biologist / Wetland Scientist
Attachments
File ref: 04.354.088
ATTACHMENT A
Figures
Figure 1.
General Location Map
Area of Detail Scale: 1 inch equals 10 miles
04.354.088
1/17/2023File Ref.
Date:
Survey Area
-0 500
Feet
1 in = 500 feet
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
Survey AreaFigure 2A.
Topographic Setting
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/20/2023
File Ref.
Date:-0 300
Feet
1 in = 300 feet
USGS Colleyville 7.5' Quad 1959 revised 1982
Survey AreaFigure 2B.
Topographic Setting
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/20/2023
File Ref.
Date:-0 300
Feet
1 in = 300 feet
USGS Colleyville 7.5' Quad 2022
Survey Area
Soil map units outside survey area
Soil Map Units
RaA - Rader fine sandy loam, 0 to 3 percent slopes
Figure 3.
Soils Map
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/17/2023
File Ref.
Date:-0 130
Feet
1 in = 130 feet
Survey AreaFigure 4.
Federal Emergency
Management Agency
Flood Insurance Rate Map
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/17/2023
File Ref.
Date:-0 130
Feet1 in = 130 feet
PANEL
48439C0085K
48439C0095K
eff. 9/25/2009
FEMA FIRM Zone Descriptions
Zone X - Areas determined to be outside the 0.2% annual
chance floodplain
Zone X - Areas of 0.2% annual chance flood; areas of 1% annual chance
flood with average depths of less than 1 foot or with drainage areas less than
1 square mile; and areas protected by levees from 1% annual chance flood
Zone AE - Special Flood Hazard Areas subject to inundation by the 1% annual
chance flood; Base flood elevations determined
Zone AE - Floodway areas in Zone AE
Zone A - Special Flood Hazard Areas subject to inundation by the 1% annual
chance flood; No base flood elevations determined
Survey Area
Aquatic Features That Do Not Meet a Definition of a Water of the United States
Pond, Isolated
Figure 5.
Aquatic Features Identified
within the Survey Area
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/18/2023
File Ref.
Date:-0 70
Feet
1 in = 70 feet
ATTACHMENT B
Site Photographs
Survey Area
Photograph Location
Aquatic Features That Do Not Meet a Definition of a Water of the United States
Pond, Isolated
Photograph Location Map
Pecan Creek Business Park
City of Southlake
Tarrant County, Texas
04.354.088
1/19/2023
File Ref.
Date:-0 70
Feet
1 in = 70 feet
Photograph 1 Photograph 2
Photograph 3 Photograph 4
Photograph 5 Photograph 6
Photograph 7 Photograph 8
Photograph 9 Photograph 10
Photograph 11 Photograph 12
ATTACHMENT C
Historic Aerial Photographs
The EDR Aerial Photo Decade Package
Pecan Creek Business Park
Southlake
Southlake, TX 76092
Inquiry Number:
January 12, 2023
7223454.1
6 Armstrong Road, 4th floor
Shelton, CT 06484
Toll Free: 800.352.0050
www.edrnet.com
2020 1"=500'Flight Year: 2020 USDA/NAIP
2016 1"=500'Flight Year: 2016 USDA/NAIP
2012 1"=500'Flight Year: 2012 USDA/NAIP
2006 1"=500'Flight Year: 2006 USDA/NAIP
1995 1"=500'Acquisition Date: January 31, 1995 USGS/DOQQ
1990 1"=500'Flight Date: January 29, 1990 NAPP
1984 1"=500'Flight Date: June 01, 1984 TXDOT
1979 1"=500'Flight Date: November 11, 1979 USDA
1972 1"=500'Flight Date: February 03, 1972 USDA
1968 1"=500'Flight Date: May 01, 1968 USGS
1950 1"=500'Flight Date: December 30, 1950 USDA
1942 1"=500'Flight Date: April 02, 1942 USDA
EDR Aerial Photo Decade Package 01/12/23
Pecan Creek Business Park
Site Name:Client Name:
Integrated Env. Solutions, Inc.
Southlake 301 W Eldorado Parkway Suite 101
Southlake, TX 76092 McKinney, TX 75069
EDR Inquiry #7223454.1 Contact:Lane Pressler
Environmental Data Resources, Inc. (EDR) Aerial Photo Decade Package is a screening tool designed to assist
environmental professionals in evaluating potential liability on a target property resulting from past activities. EDR’s
professional researchers provide digitally reproduced historical aerial photographs, and when available, provide one photo
per decade.
Search Results:
Year Scale Details Source
When delivered electronically by EDR, the aerial photo images included with this report are for ONE TIME USE
ONLY. Further reproduction of these aerial photo images is prohibited without permission from EDR. For more
information contact your EDR Account Executive.
Disclaimer - Copyright and Trademark Notice
Copyright 2023 by Environmental Data Resources, Inc. All rights reserved. Reproduction in any media or format, in whole or in part, of any report or map of
Environmental Data Resources, Inc., or its affiliates, is prohibited without prior written permission.
EDR and its logos (including Sanborn and Sanborn Map) are trademarks of Environmental Data Resources, LLC or its affiliates. All other trademarks used herein
are the property of their respective owners.
7223454 1-page 2
This Report contains certain information obtained from a variety of public and other sources reasonably available to Environmental Data Resources, LLC. It cannot
be concluded from this Report that coverage information for the target and surrounding properties does not exist from other sources. This Report is provided on an
“AS IS”, “AS AVAILABLE” basis. NO WARRANTY EXPRESS OR IMPLIED IS MADE WHATSOEVER IN CONNECTION WITH THIS REPORT.
ENVIRONMENTAL DATA RESOURCES, LLC AND ITS SUBSIDIARIES, AFFILIATES AND THIRD PARTY SUPPLIERS DISCLAIM ALL WARRANTIES, OF ANY
KIND OR NATURE, EXPRESS OR IMPLIED, ARISING OUT OF OR RELATED TO THIS REPORT OR ANY OF THE DATA AND INFORMATION PROVIDED IN
THIS REPORT, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES REGARDING ACCURACY, QUALITY, CORRECTNESS, COMPLETENESS,
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CONSEQUENTIAL OR OTHER DAMAGES OF ANY TYPE OR KIND (INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS, LOSS OF USE, OR LOSS OF
DATA), ARISING OUT OF OR IN ANY WAY CONNECTED WITH THIS REPORT OR ANY OF THE DATA AND INFORMATION PROVIDED IN THIS REPORT.
Any analyses, estimates, ratings, environmental risk levels, or risk codes provided in this Report are provided for illustrative purposes only, and are not intended to
provide, nor should they be interpreted as providing any facts regarding, or prediction or forecast of, any environmental risk for any property. Only an assessment
performed by a qualified environmental professional can provide findings, opinions or conclusions regarding the environmental risk or conditions in, on or at any
property.
7223454.1
2020
= 500'
7223454.1
2016
= 500'
7223454.1
2012
= 500'
7223454.1
2006
= 500'
7223454.1
1995
= 500'
7223454.1
1990
= 500'
7223454.1
1984
= 500'
7223454.1
1979
= 500'
7223454.1
1972
= 500'
7223454.1
1968
= 500'
7223454.1
1950
= 500'
7223454.1
1942
= 500'
Drainage Study
Timarron Creek for the Pecan Creek Development – Southlake, TX
February 14, 2023
Appendix G – Electronic Data