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For Immediate Release
July 19, 2021

Board of Water Supply Collecting Data Using Global Navigation Satellite System Technology

Data will be used to improve accuracy of water system map


HONOLULU – The Board of Water Supply (BWS) has contracted Dudek for a two-year project to locate and collect Geographic Information System (GIS) data for water system features throughout Oahu. 

The project will map about 46,000 features – BWS-owned valves, meters, and hydrants -- using high accuracy Real Time Kinematic (RTK) Global Navigation Satellite System (GNSS) technology.  Many of these features are underground in roadways and sidewalks, making them hard to find and access.

“When completed, this project will enhance the accuracy of our GIS maps and save time and effort for our field employees who need to access valves and meters,” said BWS Manager and Chief Engineer Ernest Lau. “For example, in a main break the roadway is often under water, making it hard to locate water system valves. Improving our ability to quickly find and close those valves greatly reduces the extent and impact of the break in that community.”

This project, contracted for $500,000, is a continuation of a previous effort from about 10 years ago.  The BWS used Global Positioning Satellite technology to map most of its water system features.  However, it was unable to collect data for all of them at the time and some features have since been added and/or moved. 

To collect GNSS data for each feature, the contractor’s employee will:

  • Locate the feature, place an antenna pole over it for a few seconds to get GNSS positioning and  record the data in a tablet before moving on to the next feature.
  • Possibly take photos if field conditions do not match BWS data.

The BWS is mailing out flyers to notify customers about a week in advance of the contractor’s work in an area. The work, which will take place Monday through Friday from 7:00 a.m. to 4:00 p.m., will not affect water service and will occur in the public right-of-way.  In very rare instances when the BWS needs access to its easement within private property, someone will notify the property owner that access is needed.  No customer shall be asked for any type of payment by any BWS employee or contractor for this project.

To address concerns that the project may be used to mask illegal activity:

  • All contractor employees will have special BWS Contractor ID badges;
  • Contractor employees will carry a letter and special business cards from the BWS; and
  • The BWS will post project information at, as well as on social media -- Facebook, Twitter, and Nextdoor -- for customers to check on work in their area.
  • If customers spot suspicious activity or have questions about the project, they can contact the BWS via:
    • A special hotline at 748-6500 – monitored from 7:45 a.m. to 4:30 p.m., Monday-Friday. 
      IMPORTANT - - If calling before 7:45 a.m. or after 4:30 p.m., please leave your name and  phone number so that we may return your call.
    • Email at – monitored 7:45 a.m. to 4:30 p.m. Monday- Friday.

Contractor employees will be wearing orange colored vests
with the name of the contractor on the back.



Kathleen Elliott-Pahiinui
Information Officer
Honolulu Board of Water Supply
(808) 748-5319

About the Board of Water Supply

The Board of Water Supply (BWS), a semi-autonomous agency of the City and County of Honolulu, manages Oahu’s municipal water resources and distribution system. As the largest water utility in the State, the BWS serves approximately one million customers on Oahu. The BWS embraces its mission of "Water for Life – Ka Wai Ola" – to provide a safe, dependable, and affordable water supply, now and into the future. Uwē ka lani, ola ka honua – "When the heavens weep, the earth lives."