TR9303-CS 940622CITY OF COPPELL, TEXAS
LAND USE ASSUMPTIONS FOR
ROADWAY IMPACT FEES
June, 1994
Leftwich & Associates
Urban Planners & Engineers
JBM, Engineers & Planners
Dallas, Texas
PURPOSE
In October, 1993, the City of Coppell authorized a study to implement roadway impact fees as
defined by Chapter 395 of the Texas Local Government Code. Chapter 395 requires that capital
improvements accommodate new development expected to occur over a 10 year period. A land-use
study has been conducted to establish demographic estimates for the base year (1994) and growth
within a ten-year period (2004). As part of this study an ultimate build-out of the City of Coppell was
also developed. This document defines the methodology used to establish this information.
METHODOLOGY
When developing this type of data several factors should be examined. The type, quantity and density
of existing development, growth trends, and the availability and access of vacant land were all
included the development of growth factors. Also considered was the recent zoning changes
recommended by the City of Coppell Planning & Zoning and acted upon by the City Council.
To establish a reliable base for growth estimates the 1990 census data was used as a starting point.
The North Central Council of Governments (NCICO6) Regional Data Center recently completed
their 20 year projections for population and employment within this region. This data was based on
the 1990 census data and the DKAM/EMPAL models (demand driven models using employment
locations, household income quartile, land use and travel time). A Demographic Methodology Task
Force consisting of 10 local city planners and representatives of TxDOT, NCTCOG and DART
provided review and input into the process. Final approval of this data was made by all Planning
Directors wSthin the region.
TRAFFIC SURVEY ZONES
NC/COG established Traffic Survey Zones (TSZ) for use in their transportation model in the early
1970's. These zones are based on homogeneity ofland uses and are delineated by census tracts or
natural boundaries (roadways, creeklines, raikoads, etc). For this study, TSZ served as a natural
division for collection of data. TSZ's reflect the reestablished Denton/Dallas county line and recent
annexation of land into the City of Coppell.
SERVICE AREAS
Chapter 395 dictates that a roadway service area cannot exceed three miles in diameter. All service
areas conform to this requirement and relate to existing roadway facilities as shown in Figure 1. Each
service areas consist of one to five TSZ 's. These service areas will be used in the development of
capital improvement inventories and development of fee structures.
BA SE DA TA
It was determined that the above information best sewed as a basis in establishing growth rates within
the City of Coppell. An annual growth rate was calculated from 1990 to 2010 (these rates are
compounded annually). Tables l (Employment) and 2 (Population) illustrate growth rates for each
TSZ. The projected growth rate for each TSZ was then examined for validity using the City of
Coppell aerials (December 1993), the current zoning map, the City of Coppell Subdivision
Development Map, and input from the Planning Department.
The 1994 projections of employment and population was verified using the above method.
Categories ofuses followed the c-xisting zoning ordinance: Residential ($FoED, SFo0 thru SF-I $,
9, TH-I & 2, MF-I &2, and Mit) and Nonresidential (O, R, HC, TC, LI, HI, PD, FP, SUP).
Population was verified using the C~ of Coppell Engineering Department Subdivision Development
Map, an inventory of existing housing and input from the Planning Director. Employment was
verified using an inventory of existing development, information provided by the Planning
Department, on-site review, and input from the Planning Director.
GROWTH ASSUMPTIONS AND TEN-YEAR PROJECTIONS
It was assumed that the City of Coppeli could accommodate future growth through increased school
and inlYastructure facilities. Growth areas were identified by identifying TSZ with the highest growth
factors. These area were then cross checked for available vacan! land, land uses (existing and
potential development), trends of development, and accessibility (future roadway/freeway
improvements). These growth estimates were reviewed for logical uniformity with the 1994 and
ultimate build-out of development. Mr. Gary Seib, Planning Director again provided input as the
validity of these assumptions.
ULTIMATE BUILD-OUT PROJECTIONS
An inventory ofvacant land was made using the City of Coppell aerials. Vacant gross acreage were
coded using the zoning categories listed above and modified for recent changes made by the City
Council. Roadways and landscape requirements were then subtracted from these gross acreage to
reflect the amount ofdevelopable land. Floor area ratios were taken from the City's zoning ordinance
and modified by the Planning Director to reflect a realistic density. Agriculture zoned tracts were not
included in these calculation due to the uncertainty of future zoning. Table 3 depicts these
calculations for all available vacant tracts within the city. These numbers were then added to the
existing 1994 inventory to define an ultimate build-out ofthe City of Coppell.
SUMMARY
The 1994 existing inventory (Figure 2) shows a total of 7,060 persons employed within the city
boundaries and a resident population of 21,675. These numbers conform to the estimates made by
NCTCOG and the City of Coppell Planning Department. By 2004 (Figure 3) employment will
increase by 60% for a total of 11,325. Population for 2004 is projected to increase approximately
3 7% for a total of 29,765. Ultimate build-out for the City of Coppell (Figure 4) shows the total
capacity of employment to be 95,018 and a population of 39,064. Based on these numbers the city's
! 994 residential development is 80% built and employment is at .1245% of its capacity.
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