Honolulu Water System

Honolulu Water System Improvements

Environmental Assessment (EA)


Due to undersized and aging water lines, the Board of Water Supply (BWS) plans to make improvements to the water system in Honolulu. The water systems improvements span several different neighborhoods: Iwilei, Palama, Downtown, Kakaako, Ala Moana, Waikiki and Makiki. These improvements will include replacement and upsizing of transmission mains, providing an enhanced level of reliability in meeting future increases in demands.

Some of the current existing water lines were installed before 1930. Many are 6 to 8 inches in diameter which are inadequate for the current demands. As such, there have been many breaks which causes inconveniences to businesses, residents, motorists, and pedestrians.

The water system improvements involve the use of state or county lands and funds, therefore, the environmental review process is mandated under Chapter 343 of the Hawaii Revised Statutes. In addition, federal funding sources may be pursued, therefore, the Environmental Assessment addresses compliance with cross-cutting federal authorities.

Description of Work

Gray, Hong, Nojima & Associates, Inc. (GHN) was contracted by the Honolulu BWS to prepare an environmental assessment (EA) for the Honolulu Water System Improvements. This included research and pre-assessment consultation of affected parties, and the preparation and distribution of a Draft EA and Final EA.

The EA addressed the project’s technical, economic, environmental, and social characteristics, as well as, an assessment and summary of the major impacts of the proposed action:

  • Projected timetable on demand growth, including infrastructure construction phasing
  • Documentation of archaeological/historic sites along the project route
  • Cultural Impact Assessment as required by Act 50
  • Geotechnical engineering review of available documentation and site visits
  • Biological survey of flora and fauna species in the project areas
  • Applicable federal, state, and county standards, regulations, and permits

Project Owner

Honolulu Board of Water Supply

Firm's REsponsibility

Environmental Assessment (EA)

Completion Date



Honolulu, Oahu, Hawaii