Update - Mulino State Airport - Waterline Project Starting September 28th

Update - The Mulino State Airport (4S9) Waterline project will begin Monday September 28th, 2026.

This project will improve water access for fire suppression and allow aeronautical development at the airport.

The Hangar Construction project will begin after the Waterline project is completed. A separate notice will be sent with more information when it is available.

Project/Closure Schedule:

• Waterline construction will begin Monday September 28th, 2026. 
• This project will take approximately 10 weeks to complete, and should conclude early December 2026.
• The waterline project will have minimal impacts to aircraft operations.
• The existing waterline will remain operational until the new line is tested. The only service disruption will occur during the transition to the new line. Anticipated transition dates will be shared in future updates.

Important Operating Information

(!) For the most current updates on field conditions and surface closures throughout this project, please check the latest NOTAMs.

(!!) As always, please remain outside of, and avoid low flight over closed work areas. This includes aircraft, vehicles, and pedestrians.

We appreciate your patience and understanding while we improve 4S9.