U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2004–3070

August 2004

The Colonias Monitoring Program 

provides a publicly accessible, binational, GIS database to enable civic 

leaders and citizens to inventory, analyze, and monitor growth, housing, and 

infrastructure in border communities. 

High-technology tools are provided to 

support planning efforts and development along the border, using a sustainable and comprehensive approach. 

The collective information can be used 

by nongovernmental organizations in 

preparing grant and loan applications 

for community-improvement projects. 

The U.S. Geological Survey (USGS) 

and the U.S. Department of Housing and 

Urban Development (HUD), in cooperation with the Mexican Instituto Nacional 

de Estadística Geografía e Informática 

(INEGI), have developed a joint project 

to create Internet-enabled geographic 

information systems (GISes) that will 

help cities along the United States–Mexico border manage issues related to urban 

growth and low-income housing developments.

HUD defines colonias as rural 

neighborhoods within 150 miles of the 

border that lack adequate infrastructure or 

housing, as well as other basic services. 

The colonias typically have high poverty 

rates, making it difficult for residents to 

pay for roads, sanitary-water and sewer 

systems, minimum-standard housing, 

street lighting, and other services. 

Colonias are scattered along the 

border as makeshift settlements, commonly on private land. Because these 

settlements have been established outside 

the formally sanctioned governance of 

nearby cities and towns, colonias residents have traditionally struggled to gain 

access to the public services available in 

those communities.

General Description

This joint project delineated colonias, 

developed geospatial databases describing infrastructure and land use, and established a framework for distributing World 

Wide Web-based GIS decision-support 

systems for the sister-city areas. “Sister” 

or “twin” cities are those communities 

where a city in one country borders a city 

in another, creating a large urban area 

separated by administrative boundaries. To develop the GIS databases, we 

integrated data from The National Map 

(USGS), the U.S. Census Bureau, and 

INEGI and worked with binational partners, including Federal, State, county, and 

town representatives, as well as interested 

youth and advocacy groups. 

Each Web-based mapping site incorporates common-base data layers, including transportation, digital orthophoto 

quadrangles (DOQs), digital raster graphics (DRGs), Landsat imagery, colonia 

boundaries, hydrography, demographics, 

and geographic names.

Purpose

The application

• provides Web-based planning tools 

for estimating development costs for the 

colonias, 

• includes the integration of existing 

binational geospatial, statistical, and demographic data, and 

• provides geographic-analysis tools that 

will enhance the decisionmaking processes 

of city and county planning departments.

Local government and nonprofit agencies can employ this system to facilitate 

access to grants, in order to improve living conditions in the colonias.

Figure 2. The sister cities of Eagle Pass/Piedras Negras, El Paso/Ciudad Juárez, Douglas/Agua 

Prieta, and Nogales/Nogales were chosen as project sites because of their location on the border 

and their international manufacturing and commercial opportunities, which have led to rapid spread 

of the colonias (Web-mapping services located at http://tx.usgs.gov/geography/prj_HUD.htm).

Printed on recycled paper

In cooperation with U.S. Department of Housing and Urban Development and Instituto Nacional de Estadística Geografía e Informática 

Monitoring Colonias Along the United States–Mexico Border

Figure 1. A house in a colonia of Agua Prieta, 

Sonora. Photograph by Hugo B. Rodríguez-Gallegos.
Projects in Binational Sister Cities

On the basis of local partnership 

opportunities, the GIS database developed for each sister-city pair includes 

additional layers that can facilitate planning for urban growth and the colonias’ 

infrastructure needs. 

The sister cities of Eagle Pass/Piedras 

Negras, El Paso/Ciudad Juárez, Douglas/

Agua Prieta, and Nogales/Nogales were 

chosen as project sites because of their 

location on the border and their international manufacturing and commercial 

opportunities, which have led to rapid 

spread of the colonias.

El Paso/Ciudad Juárez

The Web-based GIS database for El 

Paso/Ciudad Jarez was developed under 

local partnership with the binational Paso 

Del Norte Mapping for Public Access 

collaboration, administered by the city 

of El Paso and the Instituto Municipal de 

Investigación y Planeación. Local data 

layers include such critical infrastructure 

as police, fire stations, hospitals, schools, 

boundaries for enterprise communities, “empowerment zones,” and police, 

school, voter, and irrigation districts. 

Future plans include incorporation of 

local data from Doña Ana County, New 

Mexico, and geospatial-database access 

to the most current El Paso County 

Colonias Regional Water and Wastewater 

Plan.

Eagle Pass/Piedras Negras

Local partners that contributed data 

for Eagle Pass/Piedras Negras include 

the Middle Rio Grande Council of 

Governments, the Texas Water Development Board, and the city of Eagle 

Pass. Specific data layers include parcel 

ownership, waterlines and sewerlines, 

and critical infrastructure features. Future 

plans include incorporating zoning 

information, transportation-development 

plans, and Maverick County colonias 

master annexation plans. 

Douglas/Agua Prieta

Partners that contributed geospatial 

data for Douglas/Agua Prieta to develop 

base maps for this project include the 

Border Environment Cooperation Commission–Comisión de Cooperación Ecológica 

Fronteriza 

(BECC–COCEF), 

Cochise County, 

Arizona, the city 

of Douglas, and 

the Municipio 

de Agua Prieta, 

Sonora. With the 

help of community members 

in the cities of 

Douglas and Agua 

Prieta, waterlines 

and sewer lines, 

inadequate housing structures, 

and colonias 

were identified 

and digitized. 

These data can be 

viewed in concert 

with resources 

identified by local 

Figure 3. Waterlines and sewerlines in El Paso, 

Texas.

Figure 4. Web-based GIS decision-support system established for Nogales/Nogales.

youth groups and by other locality-reference information.

Nogales/Nogales

Many partners contributed geospatial 

data for Nogales/Nogales to develop 

base maps for this project, including the 

Secretaría de Infraestructura Urbana y 

Ecología (SIUE), the Arizona Department of Environmental Quality (ADEQ), 

the Instituto del Medio Ambiente y el 

Desarrollo Sustentable (IMADES), the 

Comisión de Agua Potable y Alcantarillado del Estado de Sonora (COAPAES), 

the University of Arizona Udall Center 

for Studies in Public Policy, the city of 

Nogales, Arizona, and the Municipio de 

Nogales, Sonora. Community members 

in the cities used waterlines, sewerlines, 

and inadequate housing structures to help 

identify colonias. Those areas identified 

by community members of Nogales, 

Sonora, were also identified by the SIUE 

as neighborhoods that are either “popular 

dwellings” or “precarious constructions,” 

and these homogeneous areas can now be 

visualized online.

Laura M. Norman, Jean W. Parcher, and 

Alven H. Lam

Edited by 

George A. Havach

Graphics by

Zachary D. Wilson and Laura M. Norman

Produced by

Sean M. Stone, Alan L. Vaughn, and 

Brent-Kaan White

COOPERATING ORGANIZATIONS

U.S. Geological Survey

U.S. Department of Housing and Urban Development

Instituto Nacional de Estadística Geografía e 

Informática

For more information, contact:

Laura M. Norman, lnorman@usgs.gov

Jean W. Parcher, jwparcher@usgs.gov

Alven H. Lam, alven_h._lam@hud.gov

For information on other USGS products and services, call 1-888-ASK-USGS 

or visit the general interest publications 

Web site on mapping, geography, and 

related topics at mac.usgs.gov/mac/isb/

pubs/pubslists/.

For additional information, visit the 

ask.usgs.gov Web site or the USGS home 

page at www.usgs.gov.