🏒
Property Ownerβœ“ Verified ActiveπŸ“ž Contact Available

HARRIS COUNTY ENGINEERING DESIGN SERVICE

πŸ“ Tomball, TX

πŸ“Š Data Overview

9+
Years Active

πŸ“„ About HARRIS COUNTY ENGINEERING DESIGN SERVICE

HARRIS COUNTY ENGINEERING DESIGN SERVICE is a property owner and development entity serving Katy, Huffman, Houston with 9+ years of documented activity.

HARRIS COUNTY ENGINEERING DESIGN SERVICE is currently active in the Texas construction market with 12 projects in the past 12 months representing $22.1M in value.

This entity also operates under 13 other registered business names: Harris County Engineering Department - Design Services, HARRIS COUNTY ENGINEERING DEPT.-DESIGN, Harris County Engineering-Design Services, and others.

πŸ† Largest Projects

1
Sidewalk Along Beltway 8 Northbound Frontage Rd.
BW8 N From Wallisville Rd. to Auburn Knoll Ave, Houston, TX 77049, Houston
$44.5M
2021-06-01
2
701 San Jacinto Street Jail MEP Upgrades
701 San Jacinto Street, Houston, TX 77002, Houston
$38.0M
2020-09-11
3
HARRIS CO VET PUBLIC HEALTHCARE FACILITY
612 CANINO ROAD, Houston, TX 77076, Houston
$19.0M
2017-07-01
4
HC SOUTH CENTRAL PLANT UPGRADE
1303 Preston Street Suite 200, Houston, TX 77042, Houston
$14.0M
2022-03-01
5
Castlewood Addition Sec 3 & 4 Subdivision Drainage Improvements - 2018
Intersection of Connorvale Rd and Russ Dr to Intersection of Connorvale Rd and Rockshire Dr, Houston, TX 77039, Houston
$12.6M
2021-10-01

πŸ“ˆ Company Insights

9+
Years Active
Small
Company Scale
$3.0M
Avg Project Size
12
Last 12 Months
Active in public records from 2016 to 2025

❓ Frequently Asked Questions

What areas does HARRIS COUNTY ENGINEERING DESIGN SERVICE serve in Texas?β–Ό
HARRIS COUNTY ENGINEERING DESIGN SERVICE has completed construction work in Katy, Huffman, Houston, Abilene, Spring and 14 other Texas cities, spanning 1 county including Harris.
What type of developments does HARRIS COUNTY ENGINEERING DESIGN SERVICE build?β–Ό
HARRIS COUNTY ENGINEERING DESIGN SERVICE is a property owner/developer in Texas.
How long has HARRIS COUNTY ENGINEERING DESIGN SERVICE been operating in Texas?β–Ό
HARRIS COUNTY ENGINEERING DESIGN SERVICE has 9+ years of documented construction activity in Texas, with public records dating back to 2016. They remain actively engaged in the Texas construction market.
How do I contact HARRIS COUNTY ENGINEERING DESIGN SERVICE?β–Ό
You can contact HARRIS COUNTY ENGINEERING DESIGN SERVICE by phone at (713) 274-3897. Their headquarters is located at 1111 Fannin Street, Suite 1200, Houston, Texas 77002.

πŸ—ΊοΈ Service Areas & Locations19 cities β€’ 1 counties

Cities (19)

KatyHuffmanHoustonAbileneSpringWebsterGreenvilleHumbleMckinneySeabrookChannelviewTomballLa PortePasadenaEl LagoBaytownAtascocitaCypressCrosby

Counties (1)

Harris County

🏒 Related Entities & Subsidiaries14 linked records

This entity group includes the following related businesses and name variations:

Harris County Engineering - Design Services Division

Primary
πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

Harris County Engineering Department - Design Services

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

HARRIS COUNTY ENGINEERING DEPT.-DESIGN

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

Harris County Engineering-Design Services

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

HARRIS COUNTY ENGINEERING DEPT

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
owner

HARRIS COUNTY ENGINEERING DESIGN SERVICE

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

HARRIS COUNTY ENGINEERING DEPARTMENT DES

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

HARRIS COUNTY ENGINEER DEPARTMENT

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

HARRIS COUNTY ENGINEERING DEPARTMENT -

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
firm

Harris County of Engineering Department

πŸ“1111 Fannin St. 11th Floor, Houston, Texas 77002
firm

Harris County Design Services

πŸ“1055 NW Freeway, Houston, Texas 77092
owner

HARRIS COUNTY ENGINEERING

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
owner

HARRIS COUNTY ENGINEERING DEPARTMENT

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
owner

HARRIS COUNTY ENGINEERING DEPARTMENT-CPD

πŸ‘€Carlos Perez
πŸ“1111 Fannin Street, Suite 1200, Houston, Texas 77002
owner

All business names: Harris County Engineering - Design Services Division β€’ Harris County Engineering Department - Design Services β€’ HARRIS COUNTY ENGINEERING DEPT.-DESIGN β€’ Harris County Engineering-Design Services β€’ HARRIS COUNTY ENGINEERING DEPT β€’ HARRIS COUNTY ENGINEERING DESIGN SERVICE β€’ HARRIS COUNTY ENGINEERING DEPARTMENT DES β€’ HARRIS COUNTY ENGINEER DEPARTMENT β€’ HARRIS COUNTY ENGINEERING DEPARTMENT - β€’ Harris County of Engineering Department β€’ Harris County Design Services β€’ HARRIS COUNTY ENGINEERING β€’ HARRIS COUNTY ENGINEERING DEPARTMENT β€’ HARRIS COUNTY ENGINEERING DEPARTMENT-CPD

πŸ“ Project Portfolio0 total

πŸ“‹ Permit

Westpark Drive Pedestrian Improvements (SW34-WPK)

16116 Westpark Drive, Houston

4K sqft
$681K
Project Registered
2025-12-08
View β†’
πŸ“‹ Permit

SAUMS RD PEDESTRIAN IMPROVEMENTS (SW29_SMS)

20100 Saums Road, Katy

1K sqft
$86K
Review Complete
2025-11-17
View β†’
πŸ“‹ Permit

Westheimer Place Drive Pedestrian Improvements (SW33_WHM)

16305 Kensley Dr, Houston

1K sqft
$181K
Project Registered
2025-11-17
View β†’
πŸ“‹ Permit

Morton Road Pedestrian Improvements (SW41_MRT)

22719 Morton Ranch Rd, Katy

1K sqft
$124K
Review Complete
2025-11-17
View β†’
πŸ“‹ Permit

Westgreen Blvd Pedestrian Improvement (SW31_WGN)

1555 Westgreen Blvd, Katy

1K sqft
$74K
Review Complete
2025-11-17
View β†’
πŸ“‹ Permit

Seabrook Sports Complex - Parking Lot - 2023 - Precinct 2

1805 N Meyer Ave, Seabrook

38K sqft
$896K
Project Registered
2025-11-12
View β†’
πŸ“‹ Permit

SIDEWALK & PARKING - WESLEY COMMUNITY CENTER

1410 Lee St, Houston

5K sqft
$1.1M
Review Complete
2025-11-01
View β†’
πŸ“‹ Permit

1010 Lamar (Annex) - Executive Floor - CAO Renovations

1010 Lamar St., 18th Floor, Houston

12K sqft
$1.5M
Review Complete
2025-10-24
View β†’
πŸ“‹ Permit

South Sheldon at Market St Intersection & Drainage Improvements

South Sheldon Road & Market Street, Channelview

5K sqft
$6.9M
Review Complete
2025-09-01
View β†’
πŸ“‹ Permit

Hike and Bike - Halls Bayou Detention Basin

North of Wiley Rd., South of Langley Rd. East of Dodson St., West of Willie St.,, Houston

126K sqft
$4.8M
Review Complete
2025-08-01
View β†’
πŸ“‹ Permit

Lockwood Overpass Parking Lot & Improvements

601 Lockwood Dr, Houston, TX 77011, Houston

111K sqft
$4.2M
Review Complete
2025-02-10
View β†’
πŸ“‹ Permit

Sidewalk - West Road From Veterans Memorial Blvd to IH-45

W Road between Veterans Memorial Blvd. and IH-45, Houston

55K sqft
$1.5M
Review Complete
2025-02-01
View β†’
πŸ“‹ Permit

Rimwood Pocket Park - Looped Sidewalk - 2023

Rimwood Road at Elderberry Lane, Houston, TX 77049, Houston

15K sqft
$95K
Inspection Complete
2024-11-01
View β†’
πŸ“‹ Permit

Blackhawk Blvd Sidewalk Project

Blackhawk from Scarsdale Blvd to Beltway 8, Houston, TX 77089, Houston

141K sqft
$2.8M
Review Complete
2024-09-11
View β†’
πŸ“‹ Permit

Mueschke 9

Draper Rd. To FM 2920, Tomball, TX 77377, Tomball

8K sqft
$4.8M
Review Complete
2024-09-02
View β†’
πŸ“‹ Permit

Trail-Fairmont Parkway-2022

Fairmont Parkway from SH 146 to Sylvan Beach Park, La Porte, TX 77571, La Porte

30K sqft
$1.0M
Review Complete
2024-06-03
View β†’
πŸ“‹ Permit

Hike & Bike Trail - Lauder Road Basin - Phase 1 - Precinct 2

Lauder Road, Houston, TX 77039, Houston

98K sqft
$1.4M
Project Closed
2024-05-01
View β†’
πŸ“‹ Permit

Intersection Improvement Vickery Street at Lauder Road - 2021

4702 Lauder Rd, Houston, TX 77039, Houston

131K sqft
$1.5M
Inspection Complete
2024-04-01
View β†’
πŸ“‹ Permit

Hike and Bike Trail - Exploration Green Trail - 2023

Exploration Green Trail Space Center Blvd to 800' South, Houston, TX 77062, Houston

9K sqft
$182K
Review Complete
2024-04-01
View β†’
πŸ“‹ Permit

Sidewalk - Holland Avenue from Clinton Dr. to 18th St.

Holland Avenue from Clinton Dr. to 18th St., Houston, TX 77547, Houston

27K sqft
$875K
Project Closed
2023-11-14
View β†’
πŸ“‹ Permit

Hiram Clarke Rd-Anderson Rd to Summerlyn Dr UPIN No. 19101MF0ZE01

Hiram Clarke Rd between Anderson Rd, Houston, TX 77053, Houston

90K sqft
$2.4M
Project Closed
2023-08-01
View β†’
πŸ“‹ Permit

1111 Fannin Basement Level Remodel

1111 Fannin, Houston, TX 77002, Houston

7K sqft
$4.0M
Review Complete
2023-08-01
View β†’
πŸ“‹ Permit

Trail - Fairmont Parkway 2021; UPIN 22102MF2FC01

HCFCD B100 to Red Bluff Rd, Pasadena, TX 77505, Pasadena

30K sqft
$2.5M
Project Closed
2023-06-01
View β†’
πŸ“‹ Permit

Sidewalk: Dell Dale Street from Woodforest Boulevard to Wallisville Road, Precinct 2; UPIN 22102MF

Dell Dale Street from Woodforest Boulevard to Wall, Channelview, TX 77530, Channelview

96K sqft
$900K
Project Closed
2023-05-15
View β†’
πŸ“‹ Permit

Asian Pavilion at Arthur Storey Park

7400 W Sam Houston Park S, Houston, TX 77072, Houston

1K sqft
$500K
Review Complete
2023-03-31
View β†’
πŸ“‹ Permit

Armand Bayou Hike & Bike Trail

Partnership Park to Fairmont Pkwy, Pasadena, TX 77505, Pasadena

0K sqft
$2.2M
Review Complete
2023-01-01
View β†’
πŸ“‹ Permit

Sidewalk - E Meyer Avenue - 2021

E Meyer Ave from SH 146 to N Meyer Ave, Seabrook, TX 77586, Seabrook

83K sqft
$679K
Project Closed
2022-11-01
View β†’
πŸ“‹ Permit

Bentley Street Sidewalk

10918 Bentley Street, Houston, TX 77093, Houston

13K sqft
$480K
Inspection Complete
2022-08-27
View β†’
πŸ“‹ Permit

HC SOUTH CENTRAL PLANT UPGRADE

1303 Preston Street Suite 200, Houston, TX 77042, Houston

13K sqft
$14.0M
Review Complete
2022-03-01
View β†’
πŸ“‹ Permit

Sidewalk Package 2, Phase III - FY 20-21

1111 Fannin, Houston, TX 77002, Houston

27K sqft
$383K
Project Closed
2022-02-15
View β†’
πŸ“‹ Permit

Sidewalk Package 1, Phase III - FY 20-21

1111 Fannin, Houston, TX 77002, Houston

14K sqft
$174K
Project Closed
2022-02-07
View β†’
πŸ“‹ Permit

Cypress Creek Greenway 2 Loop Trails at SH 249

20022 Tomball Pkwy, Houston, TX 77070, Houston

20K sqft
$1.1M
Project Closed
2022-01-01
View β†’
πŸ“‹ Permit

Dad's Club South (Paving and Sidewalks) - Design and Construction - P2- 2021

14500 Village Evergreen Trail, Houston, TX 77062, Houston

10K sqft
$82K
Project Closed
2021-12-01
View β†’
πŸ“‹ Permit

Sidewalk - Normandy Street from Woodforest Blvd. to Wallisville Rd.

Normandy St from Woodforest Blvd to Wallisville Rd, Houston, TX 77015, Houston

77K sqft
$606K
Project Closed
2021-11-16
View β†’
πŸ“‹ Permit

Water Control Improvement District (WCID) 50 Drainage Improvements-2020 UPIN No 21102MR1WF01 HCFCD

Various Locations throughout El Lago TX, El Lago, TX 77586, El Lago

242K sqft
$12.2M
Project Closed
2021-10-24
View β†’
πŸ“‹ Permit

Sidewalk - Garth Road From Spring Park Dr. To Seabird St. UPIN No. 21102MF21T01

Garth rd - between Spring Park to Seabird, Baytown, TX 77521, Baytown

0K sqft
$406K
Project Closed
2021-10-18
View β†’
πŸ“‹ Permit

Castlewood Addition Sec 3 & 4 Subdivision Drainage Improvements - 2018

Intersection of Connorvale Rd and Russ Dr to Intersection of Connorvale Rd and Rockshire Dr, Houston, TX 77039, Houston

976K sqft
$12.6M
Project Closed
2021-10-01
View β†’
πŸ“‹ Permit

Additional Parking Spaces for Child Protective Services

6300 Chimney Rock, Houston, TX 77081, Houston

12K sqft
$250K
Project Closed
2021-09-01
View β†’
πŸ“‹ Permit

Cypress Creek Greenway 1 Loop Trails at SH249

20215 Chasewood Park Dr, Houston, TX 77070, Houston

125K sqft
$1.2M
Project Closed
2021-07-02
View β†’
πŸ“‹ Permit

Sidewalk Along Beltway 8 Northbound Frontage Rd.

BW8 N From Wallisville Rd. to Auburn Knoll Ave, Houston, TX 77049, Houston

5K sqft
$44.5M
Project Closed
2021-06-01
View β†’
πŸ“‹ Permit

Sidewalk Package 2, Phase II - FY 20-21

1001 Preston, Houston, TX 77056, Houston

15K sqft
$256K
Project Closed
2021-05-15
View β†’
πŸ“‹ Permit

Sidewalk Package 1, Phase II - FY 20-21

1001 Preston, Houston, TX 77002, Houston

31K sqft
$501K
Project Closed
2021-05-15
View β†’
πŸ“‹ Permit

Bay Area Hike & Bike Trail Segment 3

7500 Bay Area Blvd., Pasadena, TX 77058, Pasadena

55K sqft
$1.5M
Project Closed
2020-11-01
View β†’
πŸ“‹ Permit

701 San Jacinto Street Jail MEP Upgrades

701 San Jacinto Street, Houston, TX 77002, Houston

640K sqft
$38.0M
Review Complete
2020-09-11
View β†’
πŸ“‹ Permit

Neuens Road Improvements from Gessner Road to Blalock Road

Neuens Road from Gessner Road to Blalock Road, Houston, TX 77080, Houston

52K sqft
$430K
Project Closed
2020-07-20
View β†’
πŸ“‹ Permit

Spring Creek Park

15012 Brown Road, Tomball, TX 77375, Tomball

1K sqft
$270K
Review Complete
2020-01-06
View β†’
πŸ“‹ Permit

Suite 290, Interior Build-Out

10555 NW Freeway, Suite 290, Houston, TX 77092, Houston

4K sqft
$292K
Project Closed
2019-12-01
View β†’
πŸ“‹ Permit

Hufsmith-Kohrville 2 Trail

Northwest Corner of Hufsmith-Kohrville Dr. and Grand Ashford Dr., Tomball, TX 77375, Tomball

52K sqft
$145K
Review Complete
2019-11-01
View β†’
πŸ“‹ Permit

Sidewalks Improvements along Woodsdale Blvd., Woodington Dr. and Frick Rd.

Woodsdale Blvd., Woodington Dr., and Frick Rd., Houston, TX 77038, Houston

15K sqft
$465K
Project Closed
2019-09-30
View β†’
πŸ“‹ Permit

Richey Road

N/A, Houston, TX 77090, Houston

60K sqft
$6.2M
Project Closed
2019-09-01
View β†’
πŸ“‹ Permit

Champion Forest Park Playground

9650 Cypresswood, Houston, TX 77069, Houston

4K sqft
$100K
Project Closed
2019-05-01
View β†’
πŸ“‹ Permit

Cleburne St Reconstruction From Ennis St to Scott St

Ennis St to Scott St, Houston, TX 77004, Houston

10K sqft
$540K
Review Complete
2019-04-01
View β†’
πŸ“‹ Permit

Timber Forest Drive from Eagles Springs Parkway to Madera Run Parkway

Timber Forest Dr., Atascocita, TX 77346, Atascocita

139K sqft
$3.0M
Project Closed
2018-11-05
View β†’
πŸ“‹ Permit

ADMIN BUILDING PLAZA RENOVATION

1001 PRESTON, Houston, TX 77002, Houston

0K sqft
$175K
Project Closed
2018-11-01
View β†’
πŸ“‹ Permit

ATASCOCITA AREA TRAILS - SECTION 1

W. LAKE HOUSTON PKWY TO N. OF Kings Park Way along HCFCD, Humble, TX 77346, Humble

$705K
Project Closed
2018-10-01
View β†’
πŸ“‹ Permit

DENNIS JOHNSTON - ADMINISTRATIVE COTTAGE

709 RILEY FUZZEL RD., Spring, TX 77373, Spring

0K sqft
$183K
Review Complete
2018-09-01
View β†’
πŸ“‹ Permit

CMAQ PHASE 1C: N ELDRIDGE PKWY

17000 NORTH ELDRIDGE PARKWAY, Tomball, TX 77377, Tomball

$4.2M
Review Complete
2018-08-01
View β†’
πŸ“‹ Permit

LAKES OF BRIDGEWATER SIDEWALK, N&S

NORTH AND SOUTH CLAY RD., Katy, TX 77449, Katy

$150K
Project Closed
2018-07-01
View β†’
πŸ“‹ Permit

MERCER VOLUNTEER COTTAGE ADDITION &RENOV

22306 ALDINE WESTFIELD ROAD, Humble, TX 77338, Humble

2K sqft
$166K
Review Complete
2018-06-01
View β†’
πŸ“‹ Permit

MERCER BOTANIC INFORMATION CENTER RENOVA

22306 ALDINE WESTFIELD ROAD, Humble, TX 77338, Humble

0K sqft
$220K
Inspection Complete
2018-06-01
View β†’
πŸ“‹ Permit

SIDEWALK: GREENHOUSE ROAD OF LANGHAM CRE

8200 GREENHOUSE RD., Cypress, TX 77433, Cypress

$134K
Project Closed
2018-05-01
View β†’
πŸ“‹ Permit

SPRINGWOODS VILLAGE NATURE PRESERVE EQUE

0 HOLZWARTH RD., Spring, TX 77389, Spring

0K sqft
$483K
Project Closed
2018-02-01
View β†’
πŸ“‹ Permit

1001 PRESTON 1ST FLOOR WINDOW RENOVATION

1001 PRESTON ST., Houston, TX 77002, Houston

0K sqft
$850K
Project Closed
2017-12-01
View β†’
πŸ“‹ Permit

6000 CANAL ST LID PARKING LOT & IMPROV.

6000 CANAL STREET, Houston, TX 77011, Houston

0K sqft
$465K
Project Closed
2017-12-01
View β†’
πŸ“‹ Permit

HARRIS CO VET PUBLIC HEALTHCARE FACILITY

612 CANINO ROAD, Houston, TX 77076, Houston

$19.0M
Project Closed
2017-07-01
View β†’
πŸ“‹ Permit

WOODLAND HILLS DRIVE PHASE 2

0 WOODLAND HILLS DRIVE, Humble, TX 77346, Humble

$8.2M
Project Closed
2017-04-01
View β†’
πŸ“‹ Permit

ADMIN BLDG HOLLY HALL RE-CLADDING

2525 HOLLY HALL STREET, Houston, TX 77054, Houston

$3.2M
Project Registered
2017-03-01
View β†’
πŸ“‹ Permit

HOWELL-SUGARLAND ROAD SIDEWALKS FROM REN

HOWELL-SUGARLAND FROM RENN TO Beechnut, Houston, TX 77083, Houston

$282K
Project Closed
2017-03-01
View β†’
πŸ“‹ Permit

RED SUMMIT SIDEWALK

RED SUMMIT DRIVE, Crosby, TX 77532, Crosby

$65K
Project Closed
2017-03-01
View β†’
πŸ“‹ Permit

ANDERSON TRAIL DITCH FROM CYPRESSWOOD DR

CYPRESSWOOD TO GRANT RD, Houston, TX 77070, Houston

$609K
Project Closed
2017-01-01
View β†’
πŸ“‹ Permit

ANDERSON TRAIL DITCH FROM CYPRESSWOOD DR

CYPRESSWOOD TO GRANT RD, Houston, TX 77070, Houston

$609K
Project Closed
2017-01-01
View β†’
πŸ“‹ Permit

ALDINE MAIL ROUTE-EAST ALDINE TOWN CENTE

EAST ALDINE MAIL ROUTE (BETWEE Russ & Fern Meadows Drives), Houston, TX 77039, Houston

$2.1M
Project Closed
2016-10-01
View β†’
πŸ“‹ Permit

KICKERILLO MISCHER PRESERVE PARKPHASE II

9860 CYPRESSWOOD DR., Houston, TX 77070, Houston

$741K
Project Closed
2016-09-01
View β†’
πŸ“‹ Permit

GRANT ROAD IMPROVEMENT PROJECT

FROM SPRING CYP TO OLD KLUGE R, Houston, TX 77429, Houston

$70K
Review Complete
2016-09-01
View β†’
πŸ“‹ Permit

GRANT ROAD SIDEWALK

EAST CYPRESS FOREST DR. TO Perry Rd., Houston, TX 77070, Houston

$150K
Project Closed
2016-07-01
View β†’
πŸ“‹ Permit

SOUTH MACGREGOR WAY FITNESS COURT

SOUTH MACGREGOR WAY & OAKCREST Dr., Houston, TX 77021, Houston

$149K
Project Closed
2016-05-01
View β†’

Data sourced from Texas TDLR, Austin Site Plans, and Building Permits

Contact Information

1 contacts from TDLR & public records

Headquarters
1111 Fannin Street, Suite 1200, Houston, Texas 77002
Key Contacts
Carlos Perez
Harris County Engineering Department
πŸ“ž (713) 274-3880
Address
10555 NW Frwy, Suite 200, Houston, Texas 77092
Tomball, TX
Data Sources