KANEOHE, OAHU (HawaiiNewsNow) –

The drilling for the tunnel of the Kaneohe-Kailua gravity sewer was completed on Tuesday.

The tunnel boring machine (TBM), nicknamed Pohakulani, finished the three mile excavation journey after 13 months.

With this, the first phase of the project concluded. The tunnel is designed to store waste water during heavy rains or backups to prevent overflows and spills for Kailua and Kaneohe.

The 10-foot wide sewer line will use gravity, rather than electricity, to transfer waste water from Kaneohe downhill to the Kailua plant.

Once finished, it will be Hawaii’s first and largest gravity sewer line to run between the Kaneohe Waste Water Pre-Treatment Facility and the Kailua Regional Waste Water Treatment Plant.

This project is also the city’s second largest construction project after the rail building campaign. It is expected to be complete in 2018.

Copyright 2016 Hawaii News Now. All rights reserved.