DR9604-CS 981020DENTON CI~i~.K PROJECT
20 October 1998
Introduction
The floodplain of Denton Creek, a tributary to the Elm Fork of the Trinity River in the city
of Coppell, is located within a developing metropolitan-area. Urban expansion has resulted in
alterations to the natural features. During the early 1980's, economic conditions led developers and the
City of Coppell to seek use of the Denton Creek floodplain. Adjacent lands to the creeks have been or
are continuing to be developed by private interests for housing and commercial development, including
utility routes, railroads, and transportation corridors.
The city of Coppell has been an active participant in the Upper Trinity River Feasibility Study,
including agreeing to implement the Corridor Development Certificate Program. This program is
directed at protection of the floodplain's values of flood water storage with associated ground water
recharge, water quality improvement, erosion prevention, fish and wildlife habitat, urban open space
and recreation. Widespread community support exists for maintaining these values in a growing
Proposed Study
Proposed studies for this area would focus on analyzing environmental restoration, wetland
restoration/preservation, streambank erosion, and'associated recreation opportunities and needs.
Potential restoration projects would be possible on lands adjacent to the creek. These restoration
activities along the modified portion of Denton Creek could include riparian forest stand improvement
and development, as well as wetland/shallow water/moist soil/mud fiats. Other riparian restoration
may exist further downstream between Denton Creek and the Elm Fork of the Trinity River.
Additionally, as a part of the restoration investigation, consideration would be'given to incorporating
pedestrian/bicycle access across the creek to allow utilization of the restoration area as an education tool
by area schools. Streambank erosion problems would be addressed by diversion of high flows through a
by-pass channel to new wetlands.
For the purpose of this study, projects within Coppell will be located within an area starting west of
Denton Tap Road, proceeding eastward along Denton Creek for approximately 3 miles and including the
area between the natural Denton Creek channel and the Elm Fork of the Trinity River down to the Sandy
Lake Bridge. The linear area (along the modified Denton Creek) would have an approximate width of 450
feet through the majority of the study area. Downstream ora channelized (permitted) reach of the creek,
the study area would investigate environmental restoration on each side of the natural creek, by-pass
channels, and undeveloped floodplain: Immediately south of Denton Creek are existing city recreation
facilities. Portions of these facilities could be used for restoration along Denton Creek.
TABLE 1
STUDY COST ESTIMATE SUMMARY
FOR CITY OF COPPELL PROJECT
Federal Non-Federal
Total
Hydrologic/Hydraulic Studies
Civil/Structural Design
Cost Engineering
Geotechnical Studies
Hazardous and Toxic Wastes
Surveys
Environmental Studies
U.S. Fish and. Wildlife Service
Cultural Resource Studies
Geographical Information System
Economic Studies
Recreation Studies
Real Estate Studies
Technical Management
Plan Formulation
Programs and Project Management
Report Preparation
Public Involvement
EIS/EA Preparation
Review Contingency
50,000 0
80,000 0
25,000 0
50,000 0
50,000 0
0 10,000
35,000 0
20,000 0
20,000 0
15,000 0
15,000 0
25,000 5,000
30,000 5,000
35,000 25,000
5,000 5,000
35,000 0
25,000 0
5,000 10,000
10,000 5,000
10,000 5,000
50,000
80,000
25,000
50,000
50,000
10,000
35,000
20,000
20,000
15,000
15,000
30,000
35,000
60,000
10,000
35,000
25,000
15,000
15,000
15,000
SUBTOTAL
CASH CONTRIBUTION
TOTAL STUDY COST
F~xpected Work Based F, xpenditures:
Coppell $50,000
NCTCOG $20,000
Corps of Engineers ' $540,000
S 540,000 $70,000 $ 610,000
(235,000) 235,00O
$ 305,000 $ 305,000 $ 610,000
H&H Studies
Civil/Structural Design
Cost Estimates
Geotechnical Studies
HTRW
Surveys
Environmental Studies
USFWS
Cultural Resource
Economic Studies
. Recreation
Real Estate
Technical Management
Plan Formulation
Project Management
Report Preparation
Public Involvement
EIS/EA Preparation
Review Continency
Total Study Cost
Total Cost
TABLE 2
STUDY COST ESTIMATE SUMMARY BY PHASE
DENTON CREEK - COPPEI,I.
$20,000 $25,000 $5,000
$25,000 $40,000 $15,000
$5,000 $10,000 $I0,000
$5,000 $4O,OOO $5,OOO
$10,000 $35,000 $5,000
$10,000 $0 $0
$10,000 $15,000 $10,000
$5,000 $10,000 $5,000
$5,000 $10,000 $5,000
$5,000 $5,000 $5,000
$10,000 $15,000 $5,000
$5,000 $5,000 $5,000
$5,000 $20,000 $10,000
$20,000 $20,000 $20,000
$5,000 $5,000 $0
$10,000 $10,000 $15,000
$0 $0 $25,000
$5,000 $5,O00 ~,000
$0 $0 $15,000
$0 $0 $15,000
$160,000 $225,000 $225,000
$610,000
Federal
non-Fedexal WIX
non-Federal Cash
$80,000
$28,000
$52,000
$135,000
$23,000
$112,000
$90,000
$19,000
$'71,000
Time (Months) 6 months 9 months 3 months